SYNOPSIS redbean.com [-?BVabdfghjkmsuvz] [-p PORT] [-D DIR] [-- SCRIPTARGS...] DESCRIPTION redbean - single-file distributable web server OVERVIEW redbean makes it possible to share web applications that run offline as a single-file Actually Portable Executable PKZIP archive which contains your assets. All you need to do is download the redbean.com program below, change the filename to .zip, add your content in a zip editing tool, and then change the extension back to .com. redbean can serve 1 million+ gzip encoded responses per second on a cheap personal computer. That performance is thanks to zip and gzip using the same compression format, which enables kernelspace copies. Another reason redbean goes fast is that it's a tiny static binary, which makes fork memory paging nearly free. redbean is also easy to modify to suit your own needs. The program itself is written as a single .c file. It embeds the Lua programming language and SQLite which let you write dynamic pages. FEATURES - Lua v5.4 - SQLite 3.35.5 - TLS v1.2 / v1.1 / v1.0 - HTTP v1.1 / v1.0 / v0.9 - Chromium-Zlib Compression - Statusz Monitoring Statistics - Self-Modifying PKZIP Object Store - Linux + Windows + Mac + FreeBSD + OpenBSD + NetBSD FLAGS -h or -? help -d daemonize -u uniprocess -z print port -m log messages -i interpreter mode -b log message bodies -a log resource usage -g log handler latency -e eval Lua code in arg -F eval Lua code in file -E show crash reports to public ips -j enable ssl client verify -k disable ssl fetch verify -Z log worker system calls -f log worker function calls -B only use stronger cryptography -X disable ssl server and client support -* permit self-modification of executable -J disable non-ssl server and client support -% hasten startup by not generating an rsa key -s increase silence [repeatable] -v increase verbosity [repeatable] -V increase ssl verbosity [repeatable] -S increase pledge sandboxing [repeatable] -H K:V sets http header globally [repeatable] -D DIR overlay assets in local directory [repeatable] -r /X=/Y redirect X to Y [repeatable] -R /X=/Y rewrites X to Y [repeatable] -K PATH tls private key path [repeatable] -C PATH tls certificate(s) path [repeatable] -A PATH add assets with path (recursive) [repeatable] -M INT tunes max message payload size [def. 65536] -t INT timeout ms or keepalive sec if <0 [def. 60000] -p PORT listen port [def. 8080; repeatable] -l ADDR listen addr [def. 0.0.0.0; repeatable] -c SEC configures static cache-control -W TTY use tty path to monitor memory pages -L PATH log file location -P PATH pid file location -U INT daemon set user id -G INT daemon set group id -w PATH launch browser on startup --strace enables system call tracing (see also -Z) --ftrace enables function call tracing (see also -f) KEYBOARD CTRL-D EXIT CTRL-C CTRL-C EXIT CTRL-E END CTRL-A START CTRL-B BACK CTRL-F FORWARD CTRL-L CLEAR CTRL-H BACKSPACE CTRL-D DELETE CTRL-N NEXT HISTORY CTRL-P PREVIOUS HISTORY CTRL-R SEARCH HISTORY CTRL-G CANCEL SEARCH ALT-< BEGINNING OF HISTORY ALT-> END OF HISTORY ALT-F FORWARD WORD ALT-B BACKWARD WORD CTRL-RIGHT FORWARD WORD CTRL-LEFT BACKWARD WORD CTRL-K KILL LINE FORWARDS CTRL-U KILL LINE BACKWARDS ALT-H KILL WORD BACKWARDS CTRL-W KILL WORD BACKWARDS CTRL-ALT-H KILL WORD BACKWARDS ALT-D KILL WORD FORWARDS CTRL-Y YANK ALT-Y ROTATE KILL RING AND YANK AGAIN CTRL-T TRANSPOSE ALT-T TRANSPOSE WORD ALT-U UPPERCASE WORD ALT-L LOWERCASE WORD ALT-C CAPITALIZE WORD CTRL-\ QUIT PROCESS CTRL-S PAUSE OUTPUT CTRL-Q UNPAUSE OUTPUT (IF PAUSED) CTRL-Q ESCAPED INSERT CTRL-ALT-F FORWARD EXPR CTRL-ALT-B BACKWARD EXPR ALT-RIGHT FORWARD EXPR ALT-LEFT BACKWARD EXPR ALT-SHIFT-B BARF EXPR ALT-SHIFT-S SLURP EXPR CTRL-SPACE SET MARK CTRL-X CTRL-X GOTO MARK CTRL-Z SUSPEND PROCESS ALT-\ SQUEEZE ADJACENT WHITESPACE PROTIP REMAP CAPS LOCK TO CTRL ──────────────────────────────────────────────────────────────────────────────── USAGE This executable is also a ZIP file that contains static assets. You can run redbean interactively in your terminal as follows: ./redbean.com -vvvmbag # starts server verbosely open http://127.0.0.1:8080/ # shows zip listing page CTRL-C # 1x: graceful shutdown CTRL-C # 2x: forceful shutdown You can override the default listing page by adding: zip redbean.com index.lua # lua server pages take priority zip redbean.com index.html # default page for directory The listing page only applies to the root directory. However the default index page applies to subdirectories too. In order for it to work, there needs to be an empty directory entry in the zip. That should already be the default practice of your zip editor. wget \ --mirror \ --convert-links \ --adjust-extension \ --page-requisites \ --no-parent \ --no-if-modified-since \ http://a.example/index.html zip -r redbean.com a.example/ # default page for directory redbean normalizes the trailing slash for you automatically: $ printf 'GET /a.example HTTP/1.0\n\n' | nc 127.0.0.1 8080 HTTP/1.0 307 Temporary Redirect Location: /a.example/ Virtual hosting is accomplished this way too. The Host is simply prepended to the path, and if it doesn't exist, it gets removed. $ printf 'GET / HTTP/1.1\nHost:a.example\n\n' | nc 127.0.0.1 8080 HTTP/1.1 200 OK Link: ; rel="canonical" If you mirror a lot of websites within your redbean then you can actually tell your browser that redbean is your proxy server, in which redbean will act as your private version of the Internet. $ printf 'GET http://a.example HTTP/1.0\n\n' | nc 127.0.0.1 8080 HTTP/1.0 200 OK Link: ; rel="canonical" If you use a reverse proxy, then redbean recognizes the following provided that the proxy forwards requests over the local network: X-Forwarded-For: 203.0.113.42:31337 X-Forwarded-Host: foo.example:80 There's a text/plain statistics page called /statusz that makes it easy to track and monitor the health of your redbean: printf 'GET /statusz\n\n' | nc 127.0.0.1 8080 redbean will display an error page using the /redbean.png logo by default, embedded as a bas64 data uri. You can override the custom page for various errors by adding files to the zip root. zip redbean.com 404.html # custom not found page Audio video content should not be compressed in your ZIP files. Uncompressed assets enable browsers to send Range HTTP request. On the other hand compressed assets are best for gzip encoding. zip redbean.com index.html # adds file zip -0 redbean.com video.mp4 # adds without compression You can have redbean run as a daemon by doing the following: sudo ./redbean.com -vvdp80 -p443 -L redbean.log -P redbean.pid kill -TERM $(cat redbean.pid) # 1x: graceful shutdown kill -TERM $(cat redbean.pid) # 2x: forceful shutdown redbean currently has a 32kb limit on request messages and 64kb including the payload. redbean will grow to whatever the system limits allow. Should fork() or accept() fail redbean will react by going into "meltdown mode" which closes lingering workers. You can trigger this at any time using: kill -USR2 $(cat redbean.pid) Another failure condition is running out of disk space in which case redbean reacts by truncating the log file. Lastly, redbean does the best job possible reporting on resource usage when the logger is in debug mode noting that NetBSD is the best at this. Your redbean is an actually portable executable, that's able to run on six different operating systems. To do that, it needs to extract a 4kb loader program to ${TMPDIR:-${HOME:-.}}/.ape that'll map your redbean into memory. It does however check to see if `ape` is on the system path beforehand. You can also "assimilate" any redbean into the platform-local executable format by running: $ file redbean.com redbean.com: DOS/MBR boot sector $ ./redbean.com --assimilate $ file redbean.com redbean.com: ELF 64-bit LSB executable ──────────────────────────────────────────────────────────────────────────────── SECURITY redbean uses a protocol polyglot for serving HTTP and HTTPS on the same port numbers. For example, both of these are valid: http://127.0.0.1:8080/ https://127.0.0.1:8080/ SSL verbosity is controlled as follows for troubleshooting: -V log ssl errors -VV log ssl state changes too -VVV log ssl informational messages too -VVVV log ssl verbose details too redbean provides hardened ASAN (Address Sanitizer) builds that proactively guard against any potential memory weaknesses that may be discovered, such as buffer overruns, use after free, etc. MDOE=asan is recomended when serving on the public Internet. redbean also supports robust sandboxing on Linux Kernel 5.13+ and OpenBSD. The recommended way to harden your redbean is to call the pledge() and unveil() functions. For example, if you have a SQLite app then the key to using these features is to connect to the db first: function OnWorkerStart() db = sqlite3.open("db.sqlite3") db:busy_timeout(1000) db:exec[[PRAGMA journal_mode=WAL]] db:exec[[PRAGMA synchronous=NORMAL]] db:exec[[SELECT x FROM warmup WHERE x = 1]] assert(unix.setrlimit(unix.RLIMIT_RSS, 100 * 1024 * 1024)) assert(unix.setrlimit(unix.RLIMIT_CPU, 4)) assert(unix.unveil("/var/tmp", "rwc")) assert(unix.unveil("/tmp", "rwc")) assert(unix.unveil(nil, nil)) assert(unix.pledge("stdio flock rpath wpath cpath", nil, unix.PLEDGE_PENALTY_RETURN_EPERM)) end What makes this technique interesting is redbean doesn't have file system access to the database file, and instead uses an inherited file descriptor that was opened beforehand. With SQLite the tmp access is only needed to support things like covering indexes. The -Z flag is also helpful to see where things go wrong, so you know which promises are needed to support your use case. pledge() will work on all Linux kernels since RHEL6 since it uses SECCOMP BPF filtering. On the other hand, unveil() requires Landlock LSM which was only introduced in 2021. If you need unveil() then be sure to test the restrictions work. Most environments don't support unveil(), so it's designed to be a no-op in unsupported environments. Alternatively, there's CLI flags which make it simple to get started: -S (online policy) This causes unix.pledge("stdio rpath inet dns id") to be called on workers after fork() is called. This permits read-only operations and APIs like Fetch() that let workers send and receive data with private and public Internet hosts. Access to the unix module is somewhat restricted, disallowing its more powerful APIs like exec. -SS (offline policy) This causes unix.pledge("stdio rpath id") to be called on workers after after fork() is called. This prevents workers from talking to the network (other than the client) and allows read-only file system access (e.g. `-D DIR` flag). The `id` group helps you to call other functions important to redbean security, such as the unix.setrlimit() function. -SSS (contained policy) This causes unix.pledge("stdio") to be called on workers after after fork() is called. This prevents workers from communicating with the network (other than the client connection) and prevents file system access (with some exceptions like logging). Redbean should only be able to serve from its own zip file in this mode. Lua script access to the unix module is highly restricted. Unlike the unix.pledge() function, these sandboxing flags use a more permissive policy on Linux. Rather than killing the process, they'll cause system calls to fail with EPERM instead. Therefore these flags should be gentler when you want security errors to be recoverable. See http://redbean.dev for further details. ──────────────────────────────────────────────────────────────────────────────── LUA SERVER PAGES Any files with the extension .lua will be dynamically served by redbean. Here's the simplest possible example: Write('Hello World') The Lua Server Page above should be able to perform at 700,000 responses per second on a Core i9, without any sort of caching. If you want a Lua handler that can do 1,000,000 responses per second, then try adding the following global handler to your /.init.lua file: function OnHttpRequest() Write('Hello World') end Here's an example of a more typical workflow for Lua Server Pages using the redbean API: SetStatus(200) SetHeader('Content-Type', 'text/plain; charset=utf-8') Write('

Hello ') Write(EscapeHtml(GetParam('name'))) We didn't need the first two lines in the previous example, because they're implied by redbean automatically if you don't set them. Responses are also buffered until the script finishes executing. That enables redbean to make HTTP as easy as possible. In the future, API capabilities will be expanded to make possible things like websockets. redbean embeds the Lua standard library. You can use packages such as io to persist and share state across requests and connections, as well as the StoreAsset function, and the lsqlite3 module. Your Lua interpreter begins its life in the main process at startup in the .init.lua, which is likely where you'll want to perform all your expensive one-time operations like importing modules. Then, as requests roll in, isolated processes are cloned from the blueprint you created. ──────────────────────────────────────────────────────────────────────────────── REPL Your redbean displays a Read-Eval-Print-Loop that lets you modify the state of the main server process while your server is running. Any changes will propagate into forked clients. Your REPL is displayed only when redbean is run as a non-daemon in a Unix terminal or the Windows 10 command prompt or PowerShell. Since the REPL is a Lua REPL it's not included in a redbean-static builds. redbean uses the same keyboard shortcuts as GNU Readline and Emacs. Some of its keyboard commands (listed in a previous section) were inspired by Paredit. A history of your commands is saved to `~/.redbean_history`. If you love the redbean repl and want to use it as your language interpreter then you can pass the `-i` flag to put redbean into interpreter mode. redbean.com -i binarytrees.lua 15 When the `-i` flag is passed (for interpreter mode), redbean won't start a web server and instead functions like the `lua` command. The first command line argument becomes the script you want to run. If you don't supply a script, then the repl without a web server is displayed. This is useful for testing since redbean extensions and modules for the Lua language, are still made available. You can also write redbean scripts with shebang lines: #!/usr/bin/redbean -i print('hello world') However UNIX operating systems usually require that interpreters be encoded in its preferred executable format. You can assimilate your redbean into the local format using the following commands: $ file redbean.com redbean.com: DOS/MBR boot sector $ ./redbean.com --assimilate $ file redbean.com redbean.com: ELF 64-bit LSB executable $ sudo cp redbean.com /usr/bin/redbean By following the above steps, redbean can be installed systemwide for multiple user accounts. It's also possible to chmod the binary to have setuid privileges. Please note that, if you do this, the UNIX section provides further details on APIs like `unix.setuid` that will help you remove root privileges from the process in the appropriate manner. ──────────────────────────────────────────────────────────────────────────────── LUA ENHANCEMENTS We've made some enhancements to the Lua language that should make it more comfortable for C/C++ and Python developers. Some of these - redbean supports a printf modulus operator, like Python. For example, you can say `"hello %s" % {"world"}` instead of `string.format("hello %s", "world")`. - redbean supports a string multiply operator, like Python. For example, you can say `"hi" * 2` instead of `string.rep("hi", 2)`. - redbean supports octal (base 8) integer literals. For example `0644 == 420` is the case in redbean, whereas in upstream Lua `0644 == 644` would be the case. - redbean supports binary (base 2) integer literals. For example `0b1010 == 10` is the case in redbean, whereas in upstream Lua `0b1010` would result in an error. - redbean supports the GNU syntax for the ASCII ESC character in string literals. For example, `"\e"` is the same as `"\x1b"`. ──────────────────────────────────────────────────────────────────────────────── GLOBALS arg: array[str] Array of command line arguments, excluding those parsed by getopt() in the C code, which stops parsing at the first non-hyphenated arg. In some cases you can use the magic -- argument to delimit C from Lua arguments. For example, if you launch your redbean as follows: redbean.com -v arg1 arg2 Then your `/.init.lua` file will have the `arg` array like: arg[-1] = '/usr/bin/redbean.com' arg[ 0] = '/zip/.init.lua' arg[ 1] = 'arg1' arg[ 2] = 'arg2' If you launch redbean in interpreter mode (rather than web server) mode, then an invocation like this: ./redbean.com -i script.lua arg1 arg2 Would have an `arg` array like this: arg[-1] = './redbean.com' arg[ 0] = 'script.lua' arg[ 1] = 'arg1' arg[ 2] = 'arg2' ──────────────────────────────────────────────────────────────────────────────── SPECIAL PATHS / redbean will generate a zip central directory listing for this page, and this page only, but only if there isn't an /index.lua or /index.html file defined. /.init.lua This script is run once in the main process at startup. This lets you modify the state of the Lua interpreter before connection processes are forked off. For example, it's a good idea to do expensive one-time computations here. You can also use this file to call the ProgramFOO() functions below. The init module load happens after redbean's arguments and zip assets have been parsed, but before calling functions like socket() and fork(). Note that this path is a hidden file so that it can't be unintentionally run by the network client. /.reload.lua This script is run from the main process when SIGHUP is received. This only applies to redbean when running in daemon mode. Any changes that are made to the Lua interpreter state will be inherited by future forked connection processes. Note that this path is a hidden file so that it can't be unintentionally run by the network client. /.lua/... Your Lua modules go in this directory. The way it works is redbean sets Lua's package.path to /zip/.lua/?.lua;/zip/.lua/?/init.lua by default. Cosmopolitan Libc lets system calls like open read from the ZIP structure, if the filename is prefixed with /zip/. So this works like magic. /redbean.png If it exists, it'll be used as the / listing page icon, embedded as a base64 URI. /usr/share/zoneinfo This directory contains a subset of the timezone database. Your `TZ` environment variable controls which one of these files is used by functions such as unix.localtime(). /usr/share/ssl/root This directory contains your root certificate authorities. It is needed so the Fetch() HTTPS client API can verify that a remote certificate was signed by a third party. You can add your own certificate files to this directory within the ZIP executable. If you enable HTTPS client verification then redbean will check that HTTPS clients (a) have a certificate and (b) it was signed. /.args Specifies default command-line arguments. There's one argument per line. Trailing newline is ignored. If the special argument `...` is *not* encountered, then the replacement will only happen if *no* CLI args are specified. If the special argument `...` *is* encountered, then it'll be replaced with whatever CLI args were specified by the user. For example, you might want to use redbean.com in interpreter mode, where your script file is inside the zip. Then, if your redbean is run, what you want is to have the default behavior be running your script. In that case, you might: $ cat <<'EOF' >.args -i /zip/hello.lua EOF $ cat <<'EOF' >hello.lua print("hello world") EOF $ zip redbean.com .args hello.lua $ ./redbean.com hello world Please note that if you ran: $ ./redbean.com -vv Then the default mode of redbean will kick back in. To prevent that from happening, simply add the magic arg `...` to the end of your `.args` file. ──────────────────────────────────────────────────────────────────────────────── HOOKS OnHttpRequest() If this function is defined in the global scope by your /.init.lua then redbean will call it at the earliest possible moment to hand over control for all messages (with the exception of OPTIONS *). See functions like Route which asks redbean to do its default thing from the handler. OnClientConnection(ip:int, port:int, serverip:int, serverport:int) → bool If this function is defined it'll be called from the main process each time redbean accepts a new client connection. If it returns `true`, redbean will close the connection without calling fork. OnLogLatency(reqtimeus:int, contimeus:int) If this function is defined it'll be called from the main process each time redbean completes handling of a request, but before the response is sent. The handler received the time (in µs) since the request handling and connection handling started. OnProcessCreate(pid:int, ip:int, port:int, serverip:int, serverport:int) If this function is defined it'll be called from the main process each time redbean forks a connection handler worker process. The ip/port of the remote client is provided, along with the ip/port of the listening interface that accepted the connection. This may be used to create a server activity dashboard, in which case the data provider handler should set SetHeader('Connection','Close'). This won't be called in uniprocess mode. OnProcessDestroy(pid:int) If this function is defined it'll be called from the main process each time redbean reaps a child connection process using wait4(). This won't be called in uniprocess mode. OnServerHeartbeat() If this function is defined it'll be called from the main process on each server heartbeat. The heartbeat interval is configurable with ProgramHeartbeatInterval. OnServerListen(socketdescriptor:int,serverip:int,serverport:int) → bool If this function is defined it'll be called from the main process before redbean starts listening on a port. This hook can be used to modify socket configuration to set `SO_REUSEPORT`, for example. If it returns `true`, redbean will not listen to that ip/port. OnServerStart() If this function is defined it'll be called from the main process right before the main event loop starts. OnServerStop() If this function is defined it'll be called from the main process after all the connection processes have been reaped and exit() is ready to be called. OnWorkerStart() If this function is defined it'll be called from the child worker process after it's been forked and before messages are handled. This won't be called in uniprocess mode. OnWorkerStop() If this function is defined it'll be called from the child worker process once _exit() is ready to be called. This won't be called in uniprocess mode. ──────────────────────────────────────────────────────────────────────────────── FUNCTIONS Write(data:str) Appends data to HTTP response payload buffer. This is buffered independently of headers. SetStatus(code:int[, reason:str]) Starts an HTTP response, specifying the parameters on its first line. reason is optional since redbean can fill in the appropriate text for well-known magic numbers, e.g. 200, 404, etc. This method will reset the response and is therefore mutually exclusive with ServeAsset and other Serve* functions. If this function isn't called, then the default behavior is to send 200 OK. SetHeader(name:str, value:str) Appends HTTP header to response header buffer. name is case-insensitive and restricted to non-space ASCII. value is a UTF-8 string that must be encodable as ISO-8859-1. Leading and trailing whitespace is trimmed automatically. Overlong characters are canonicalized. C0 and C1 control codes are forbidden, with the exception of tab. This function automatically calls SetStatus(200, "OK") if a status has not yet been set. As SetStatus and Serve* functions reset the response, SetHeader needs to be called after SetStatus and Serve* functions are called. The header buffer is independent of the payload buffer. Neither is written to the wire until the Lua Server Page has finished executing. This function disallows the setting of certain headers such as Content-Range and Date, which are abstracted by the transport layer. In such cases, consider calling ServeAsset. SetCookie(name:str, value:str[, options:table]) Appends Set-Cookie HTTP header to the response header buffer. Several Set-Cookie headers can be added to the same response. __Host- and __Secure- prefixes are supported and may set or overwrite some of the options (for example, specifying __Host- prefix sets the Secure option to true, sets the path to "/", and removes the Domain option). The following options can be used (their lowercase equivalents are supported as well): - Expires: sets the maximum lifetime of the cookie as an HTTP-date timestamp. Can be specified as a Date in the RFC1123 (string) format or as a UNIX timestamp (number of seconds). - MaxAge: sets number of seconds until the cookie expires. A zero or negative number will expire the cookie immediately. If both Expires and MaxAge are set, MaxAge has precedence. - Domain: sets the host to which the cookie will be sent. - Path: sets the path that must be present in the request URL, or the client will not send the Cookie header. - Secure: (bool) requests the cookie to be only send to the server when a request is made with the https: scheme. - HttpOnly: (bool) forbids JavaScript from accessing the cookie. - SameSite: (Strict, Lax, or None) controls whether a cookie is sent with cross-origin requests, providing some protection against cross-site request forgery attacks. GetParam(name:str) → value:str Returns first value associated with name. name is handled in a case-sensitive manner. This function checks Request-URL parameters first. Then it checks application/x-www-form-urlencoded from the message body, if it exists, which is common for HTML forms sending POST requests. If a parameter is supplied matching name that has no value, e.g. foo in ?foo&bar=value, then the returned value will be nil, whereas for ?foo=&bar=value it would be "". To differentiate between no-equal and absent, use the HasParam function. The returned value is decoded from ISO-8859-1 (only in the case of Request-URL) and we assume that percent-encoded characters were supplied by the client as UTF-8 sequences, which are returned exactly as the client supplied them, and may therefore may contain overlong sequences, control codes, NUL characters, and even numbers which have been banned by the IETF. It is the responsibility of the caller to impose further restrictions on validity, if they're desired. EscapeHtml(str) → str Escapes HTML entities: The set of entities is &><"' which become &><"'. This function is charset agnostic and will not canonicalize overlong encodings. It is assumed that a UTF-8 string will be supplied. See escapehtml.c. LaunchBrowser([path:str]) Launches web browser on local machine with URL to this redbean server. It is the responsibility of the caller to escape the path with EscapePath if needed, as it's not escaped automatically. This function may be called from /.init.lua. CategorizeIp(ip:uint32) → str Returns a string describing an IP address. This is currently Class A granular. It can tell you if traffic originated from private networks, ARIN, APNIC, DOD, etc. DecodeBase64(ascii:str) → binary:str Turns ASCII into binary, in a permissive way that ignores characters outside the base64 alphabet, such as whitespace. See decodebase64.c. DecodeLatin1(iso-8859-1:str) → utf-8:str Turns ISO-8859-1 string into UTF-8. EncodeBase64(binary:str) → ascii:str Turns binary into ASCII. This can be used to create HTML data: URIs that do things like embed a PNG file in a web page. See encodebase64.c. DecodeJson(input:str) ├─→ int64 ├─→ string ├─→ double ├─→ array ├─→ object ├─→ false ├─→ true ├─→ nil └─→ nil, error:str Turns JSON string into a Lua data structure. This is a generally permissive parser, in the sense that like v8, it permits scalars as top-level values. Therefore we must note that this API can be thought of as special, in the sense val = assert(DecodeJson(str)) will usually do the right thing, except in cases where false or null are the top-level value. In those cases, it's needed to check the second value too in order to discern from error val, err = DecodeJson(str) if not val then if err then print('bad json', err) elseif val == nil then print('val is null') elseif val == false then print('val is false') end end This parser supports 64-bit signed integers. If an overflow happens, then the integer is silently coerced to double, as consistent with v8. If a double overflows into Infinity, we coerce it to `null` since that's what v8 does, and the same goes for underflows which, like v8, are coerced to 0.0. When objects are parsed, your Lua object can't preserve the the original ordering of fields. As such, they'll be sorted by EncodeJson() and may not round-trip with original intent This parser has perfect conformance with JSONTestSuite. This parser validates utf-8 and utf-16. EncodeJson(value[, options:table]) ├─→ json:str ├─→ true [if useoutput] └─→ nil, error:str Turns Lua data structure into JSON string. Since Lua tables are both hashmaps and arrays, we use a simple fast algorithm for telling the two apart. Tables with non-zero length (as reported by `#`) are encoded as arrays, and any non-array elements are ignored. For example: >: EncodeJson({2}) "[2]" >: EncodeJson({[1]=2, ["hi"]=1}) "[2]" If there are holes in your array, then the serialized array will exclude everything after the first hole. If the beginning of your array is a hole, then an error is returned. >: EncodeJson({[1]=1, [3]=3}) "[1]" >: EncodeJson({[2]=1, [3]=3}) "[]" >: EncodeJson({[2]=1, [3]=3}) nil "json objects must only use string keys" If the raw length of a table is reported as zero, then we check for the magic element `[0]=false`. If it's present, then your table will be serialized as empty array `[]`. An entry is inserted by DecodeJson() automatically, only when encountering empty arrays, and it's necessary in order to make empty arrays round-trip. If raw length is zero and `[0]=false` is absent, then your table will be serialized as an iterated object. >: EncodeJson({}) "{}" >: EncodeJson({[0]=false}) "[]" >: EncodeJson({["hi"]=1}) "{\"hi\":1}" >: EncodeJson({["hi"]=1, [0]=false}) "[]" >: EncodeJson({["hi"]=1, [7]=false}) nil "json objects must only use string keys" The following options may be used: - useoutput: (bool=false) encodes the result directly to the output buffer and returns `true` value. This option is ignored if used outside of request handling code. - sorted: (bool=true) Lua uses hash tables so the order of object keys is lost in a Lua table. So, by default, we use `strcmp` to impose a deterministic output order. If you don't care about ordering then setting `sorted=false` should yield a performance boost in serialization. - pretty: (bool=false) Setting this option to `true` will cause tables with more than one entry to be formatted across multiple lines for readability. - indent: (str=" ") This option controls the indentation of pretty formatting. This field is ignored if `pretty` isn't `true`. - maxdepth: (int=64) This option controls the maximum amount of recursion the serializer is allowed to perform. The max is 32767. You might not be able to set it that high if there isn't enough C stack memory. Your serializer checks for this and will return an error rather than crashing. This function will return an error if: - `value` is cyclic - `value` has depth greater than 64 - `value` contains functions, user data, or threads - `value` is table that blends string / non-string keys - Your serializer runs out of C heap memory (setrlimit) We assume strings in `value` contain UTF-8. This serializer currently does not produce UTF-8 output. The output format is right now ASCII. Your UTF-8 data will be safely transcoded to \uXXXX sequences which are UTF-16. Overlong encodings in your input strings will be canonicalized rather than validated. NaNs are serialized as `null` and Infinities are `null` which is consistent with the v8 behavior. EncodeLua(value[, options:table]) ├─→ luacode:str ├─→ true [if useoutput] └─→ nil, error:str Turns Lua data structure into Lua code string. Since Lua uses tables as both hashmaps and arrays, tables will only be serialized as an array with determinate order, if it's an array in the strictest possible sense. 1. for all 𝑘=𝑣 in table, 𝑘 is an integer ≥1 2. no holes exist between MIN(𝑘) and MAX(𝑘) 3. if non-empty, MIN(𝑘) is 1 In all other cases, your table will be serialized as an object which is iterated and displayed as a list of (possibly) sorted entries that have equal signs. >: EncodeLua({3, 2}) "{3, 2}" >: EncodeLua({[1]=3, [2]=3}) "{3, 2}" >: EncodeLua({[1]=3, [3]=3}) "{[1]=3, [3]=3}" >: EncodeLua({["hi"]=1, [1]=2}) "{[1]=2, hi=1}" The following options may be used: - useoutput: (bool=false) encodes the result directly to the output buffer and returns `true` value. This option is ignored if used outside of request handling code. - sorted: (bool=true) Lua uses hash tables so the order of object keys is lost in a Lua table. So, by default, we use `strcmp` to impose a deterministic output order. If you don't care about ordering then setting `sorted=false` should yield a performance boost in serialization. - pretty: (bool=false) Setting this option to `true` will cause tables with more than one entry to be formatted across multiple lines for readability. - indent: (str=" ") This option controls the indentation of pretty formatting. This field is ignored if `pretty` isn't `true`. - maxdepth: (int=64) This option controls the maximum amount of recursion the serializer is allowed to perform. The max is 32767. You might not be able to set it that high if there isn't enough C stack memory. Your serializer checks for this and will return an error rather than crashing. If a user data object has a `__repr` or `__tostring` meta method, then that'll be used to encode the Lua code. This serializer is designed primarily to describe data. For example, it's used by the REPL where we need to be able to ignore errors when displaying data structures, since showing most things imperfectly is better than crashing. Therefore this isn't the kind of serializer you'd want to use to persist data in prod. Try using the JSON serializer for that purpose. Non-encodable value types (e.g. threads, functions) will be represented as a string literal with the type name and pointer address. The string description is of an unspecified format that could most likely change. This encoder detects cyclic tables; however instead of failing, it embeds a string of unspecified layout describing the cycle. Integer literals are encoded as decimal. However if the int64 number is ≥256 and has a population count of 1 then we switch to representing the number in hexadecimal, for readability. Hex numbers have leading zeroes added in order to visualize whether the number fits in a uint16, uint32, or int64. Also some numbers can only be encoded expressionally. For example, NaNs are serialized as `0/0`, and Infinity is `math.huge`. >: 7000 7000 >: 0x100 0x0100 >: 0x10000 0x00010000 >: 0x100000000 0x0000000100000000 >: 0/0 0/0 >: 1.5e+9999 math.huge >: -9223372036854775807 - 1 -9223372036854775807 - 1 The only failure return condition currently implemented is when C runs out of heap memory. EncodeLatin1(utf-8:str[, flags:int]) → iso-8859-1:str Turns UTF-8 into ISO-8859-1 string. EscapeFragment(str) → str Escapes URL #fragment. The allowed characters are -/?.~_@:!$&'()*+,;=0-9A-Za-z and everything else gets %XX encoded. Please note that '& can still break HTML and that '() can still break CSS URLs. This function is charset agnostic and will not canonicalize overlong encodings. It is assumed that a UTF-8 string will be supplied. See kescapefragment.c. EscapeHost(str) → str Escapes URL host. See kescapeauthority.c EscapeLiteral(str) → str Escapes JavaScript or JSON string literal content. The caller is responsible for adding the surrounding quotation marks. This implementation \uxxxx sequences for all non-ASCII sequences. HTML entities are also encoded, so the output doesn't need EscapeHtml. This function assumes UTF-8 input. Overlong encodings are canonicalized. Invalid input sequences are assumed to be ISO-8859-1. The output is UTF-16 since that's what JavaScript uses. For example, some individual codepoints such as emoji characters will encode as multiple \uxxxx sequences. Ints that are impossible to encode as UTF-16 are substituted with the \xFFFD replacement character. See escapejsstringliteral.c. EscapeParam(str) → str Escapes URL parameter name or value. The allowed characters are -.*_0-9A-Za-z and everything else gets %XX encoded. This function is charset agnostic and will not canonicalize overlong encodings. It is assumed that a UTF-8 string will be supplied. See kescapeparam.c. EscapePass(str) → str Escapes URL password. See kescapeauthority.c. EscapePath(str) → str Escapes URL path. This is the same as EscapeSegment except slash is allowed. The allowed characters are -.~_@:!$&'()*+,;=0-9A-Za-z/ and everything else gets %XX encoded. Please note that '& can still break HTML, so the output may need EscapeHtml too. Also note that '() can still break CSS URLs. This function is charset agnostic and will not canonicalize overlong encodings. It is assumed that a UTF-8 string will be supplied. See kescapepath.c. EscapeSegment(str) → str Escapes URL path segment. This is the same as EscapePath except slash isn't allowed. The allowed characters are -.~_@:!$&'()*+,;=0-9A-Za-z and everything else gets %XX encoded. Please note that '& can still break HTML, so the output may need EscapeHtml too. Also note that '() can still break CSS URLs. This function is charset agnostic and will not canonicalize overlong encodings. It is assumed that a UTF-8 string will be supplied. See kescapesegment.c. EscapeUser(str) → str Escapes URL username. See kescapeauthority.c. EvadeDragnetSurveillance(bool) If this option is programmed then redbean will not transmit a Server Name Indicator (SNI) when performing Fetch() requests. This function is not available in unsecure mode. Fetch(url:str[,body:str|{method=value:str,body=value:str,headers=table,...}]) ├─→ status:int, {header:str=value:str,...}, body:str └─→ nil, error:str Sends an HTTP/HTTPS request to the specified URL. If only the URL is provided, then a GET request is sent. If both URL and body parameters are specified, then a POST request is sent. If any other method needs to be specified (for example, PUT or DELETE), then passing a table as the second value allows setting request method, body, and headers, as well as some other options: - method (default = "GET"): sets the method to be used for the request. The specified method is converted to uppercase. - body (default = ""): sets the body value to be sent. - headers: sets headers for the request using the key/value pairs from this table. Only string keys are used and all the values are converted to strings. - followredirect (default = true): forces temporary and permanent redirects to be followed. This behavior can be disabled by passing `false`. - maxredirects (default = 5): sets the number of allowed redirects to minimize looping due to misconfigured servers. When the number is exceeded, the last response is returned. When the redirect is being followed, the same method and body values are being sent in all cases except when 303 status is returned. In that case the method is set to GET and the body is removed before the redirect is followed. Note that if these (method/body) values are provided as table fields, they will be modified in place. FormatHttpDateTime(seconds:int) → rfc1123:str Converts UNIX timestamp to an RFC1123 string that looks like this: Mon, 29 Mar 2021 15:37:13 GMT. See formathttpdatetime.c. FormatIp(uint32) → str Turns integer like 0x01020304 into a string like 1.2.3.4. See also ParseIp for the inverse operation. GetAssetComment(path:str) → str Returns comment text associated with asset in the ZIP central directory. Also available as GetComment (deprecated). GetAssetLastModifiedTime(path:str) → seconds:number Returns UNIX timestamp for modification time of a ZIP asset (or local file if the -D flag is used). If both a file and a ZIP asset are present, then the file is used. Also available as GetLastModifiedTime (deprecated). GetAssetMode(path:str) → int Returns UNIX-style octal mode for ZIP asset (or local file if the -D flag is used). If both a file and a ZIP asset are present, then the file is used. GetAssetSize(path:str) → int Returns byte size of uncompressed contents of ZIP asset (or local file if the -D flag is used). If both a file and a ZIP asset are present, then the file is used. GetBody() → str Returns the request message body if present or an empty string. Also available as GetPayload (deprecated). GetCookie(name:str) → str Returns cookie value. GetCryptoHash(name:str,payload:str[,key:str]) → str Returns value of the specified cryptographic hash function. If the key is provided, then HMAC value of the same function is returned. The name can be one of the following strings: MD5, SHA1, SHA224, SHA256, SHA384, SHA512, and BLAKE2B256. GetRemoteAddr() → ip:uint32,port:uint16 Returns client ip4 address and port, e.g. 0x01020304,31337 would represent 1.2.3.4:31337. This is the same as GetClientAddr except it will use the ip:port from the X-Forwarded-For header, only if IsPrivateIp or IsLoopbackIp return true. When multiple addresses are present in the header, the last/right-most address is used. GetResponseBody() ├─→ body:str └─→ nil, error:str Returns the (uncompressed) response message body if present or an empty string. May also return a partial or empty string during streaming, as the full content may not be known at the call time. Returns an error when decompression fails. GetClientAddr() → ip:uint32,port:uint16 Returns client socket ip4 address and port, e.g. 0x01020304,31337 would represent 1.2.3.4:31337. Please consider using GetRemoteAddr instead, since the latter takes into consideration reverse proxy scenarios. GetClientFd() → int Returns file descriptor being used for client connection. This is useful for scripts that want to use unix:fork(). IsClientUsingSsl() → bool Returns true if client connection has begun being managed by the MbedTLS security layer. This is an important thing to consider if a script is taking control of GetClientFd() GetServerAddr() → ip:uint32,port:uint16 Returns address to which listening server socket is bound, e.g. 0x01020304,8080 would represent 1.2.3.4:8080. If -p 0 was supplied as the listening port, then the port in this string will be whatever number the operating system assigned. GetDate() → seconds:int Returns date associated with request that's used to generate the Date header, which is now, give or take a second. The returned value is a UNIX timestamp. GetHeader(name:str) → value:str Returns HTTP header. name is case-insensitive. The header value is returned as a canonical UTF-8 string, with leading and trailing whitespace trimmed, which was decoded from ISO-8859-1, which is guaranteed to not have C0/C1 control sequences, with the exception of the tab character. Leading and trailing whitespace is automatically removed. In the event that the client suplies raw UTF-8 in the HTTP message headers, the original UTF-8 sequence can be losslessly restored by counter-intuitively recoding the returned string back to Latin1. If the requested header is defined by the RFCs as storing comma-separated values (e.g. Allow, Accept-Encoding) and the field name occurs multiple times in the message, then this function will fold those multiple entries into a single string. GetHeaders() → {name:str=value:str,...} Returns HTTP headers as dictionary mapping header key strings to their UTF-8 decoded values. The ordering of headers from the request message is not preserved. Whether or not the same key can repeat depends on whether or not it's a standard header, and if so, if it's one of the ones that the RFCs define as repeatable. See khttprepeatable.c. Those headers will not be folded. Standard headers which aren't on that list, will be overwritten with the last-occurring one during parsing. Extended headers are always passed through exactly as they're received. Please consider using GetHeader API if possible since it does a better job abstracting these issues. GetLogLevel() → int Returns logger verbosity level. Likely return values are kLogDebug > kLogVerbose > kLogInfo > kLogWarn > kLogError > kLogFatal. GetHost() → str Returns host associated with request. This will be the Host header, if it's supplied. Otherwise it's the bind address. GetHostOs() → str Returns string that describes the host OS. This can return: - `"LINUX"` - `"METAL"` - `"WINDOWS"` - `"XNU"` - `"NETBSD"` - `"FREEBSD"` - `"OPENBSD"` GetMonospaceWidth(str|char) → int Returns monospace display width of string. This is useful for fixed-width formatting. For example, CJK characters typically take up two cells. This function takes into consideration combining characters, which are discounted, as well as control codes and ANSI escape sequences. GetMethod() → str Returns HTTP method. Normally this will be GET, HEAD, or POST in which case redbean normalizes this value to its uppercase form. Anything else that the RFC classifies as a "token" string is accepted too, which might contain characters like &". GetParams() → {{name:str[,value:str]},...} Returns name=value parameters from Request-URL and application/x-www-form-urlencoded message body in the order they were received. This may contain duplicates. The inner array will have either one or two items, depending on whether or not the equals sign was used. GetPath() → str Returns the Request-URL path. This is guaranteed to begin with "/". It is further guaranteed that no "//" or "/." exists in the path. The returned value is returned as a UTF-8 string which was decoded from ISO-8859-1. We assume that percent-encoded characters were supplied by the client as UTF-8 sequences, which are returned exactly as the client supplied them, and may therefore may contain overlong sequences, control codes, NUL characters, and even numbers which have been banned by the IETF. redbean takes those things into consideration when performing path safety checks. It is the responsibility of the caller to impose further restrictions on validity, if they're desired. GetEffectivePath() → str Returns path as it was resolved by the routing algorithms, which might contain the virtual host prepended if used. GetScheme() → str Returns scheme from Request-URL, if any. GetSslIdentity() → str Returns certificate subject or PSK identity from the current SSL session. `nil` is returned for regular (non-SSL) connections. GetStatus() → int Returns current status (as set by an earlier SetStatus call) or `nil` if the status hasn't been set yet. GetTime() → seconds:number Returns current time as a UNIX timestamp with 0.0001s precision. GetUrl() → str Returns the effective Request-URL as an ASCII string, where illegal characters or UTF-8 is guaranteed to be percent encoded, and has been normalized to include either the Host or X-Forwarded-Host headers, if they exist, and possibly a scheme too if redbean is being used as an HTTP proxy server. In the future this API might change to return an object instead. GetHttpVersion() → int Returns the request HTTP protocol version, which can be 9 for HTTP/0.9, 10 for HTTP/1.0, or 11 for HTTP/1.1. Also available as GetVersion (deprecated). GetHttpReason(code:int) → str Returns a string describing the HTTP reason phrase. See gethttpreason.c GetRandomBytes([length:int]) → str Returns string with the specified number of random bytes (1..256). If no length is specified, then a string of length 16 is returned. GetRedbeanVersion() → int Returns the Redbean version in the format 0xMMmmpp, with major (MM), minor (mm), and patch (pp) versions encoded. The version value 1.4 would be represented as 0x010400. GetZipPaths([prefix:str]) → {path:str,...} Returns paths of all assets in the zip central directory, prefixed by a slash. If prefix parameter is provided, then only paths that start with the prefix (case sensitive) are returned. HasParam(name:str) → bool Returns true if parameter with name was supplied in either the Request-URL or an application/x-www-form-urlencoded message body. HidePath(prefix:str) Programs redbean / listing page to not display any paths beginning with prefix. This function should only be called from /.init.lua. IsHiddenPath(path:str) → bool Returns true if the prefix of the given path is set with HidePath. IsPublicIp(uint32) → bool Returns true if IP address is not a private network (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) and is not localhost (127.0.0.0/8). Note: we intentionally regard TEST-NET IPs as public. IsPrivateIp(uint32) → bool Returns true if IP address is part of a private network (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16). IsLoopbackIp(uint32) → bool Returns true if IP address is part of the localhost network (127.0.0.0/8). IsAssetCompressed(path:str) → bool Returns true if ZIP artifact at path is stored on disk using DEFLATE compression. Also available as IsCompressed (deprecated). IndentLines(str[, int]) → str Adds spaces to beginnings of multiline string. If the int parameter is not supplied then 1 space will be added. LoadAsset(path:str) → str Returns contents of file as string. The asset may be sourced from either the zip (decompressed) or the local filesystem if the -D flag was used. If slurping large file into memory is a concern, then consider using ServeAsset which can serve directly off disk. StoreAsset(path:str, data:str[, mode:int]) Stores asset to executable's ZIP central directory. This currently happens in an append-only fashion and is still largely in the proof-of-concept stages. Currently only supported on Linux, XNU, and FreeBSD. In order to use this feature, the -* flag must be passed. Log(level:int, message:str) Emits message string to log, if level is less than or equal to GetLogLevel. If redbean is running in interactive mode, then this will log to the console. If redbean is running as a daemon or the -L LOGFILE flag is passed, then this will log to the file. Reasonable values for level are kLogDebug > kLogVerbose > kLogInfo > kLogWarn > kLogError > kLogFatal. The logger emits timestamps in the local timezone with microsecond precision. If log entries are emitted more frequently than once per second, then the log entry will display a delta timestamp, showing how much time has elapsed since the previous log entry. This behavior is useful for quickly measuring how long various portions of your code take to execute. ParseHttpDateTime(rfc1123:str) → seconds:int Converts RFC1123 string that looks like this: Mon, 29 Mar 2021 15:37:13 GMT to a UNIX timestamp. See parsehttpdatetime.c. ParseUrl(url:str[, flags:int]) → URL Parses URL. An object containing the following fields is returned: - `scheme` is a string, e.g. `"http"` - `user` is the username string, or nil if absent - `pass` is the password string, or nil if absent - `host` is the hostname string, or nil if `url` was a path - `port` is the port string, or nil if absent - `path` is the path string, or nil if absent - `params` is the URL paramaters, e.g. `/?a=b&c` would be represented as the data structure `{{"a", "b"}, {"c"}, ...}` - `fragment` is the stuff after the `#` character `flags` may have: - `kUrlPlus` to turn `+` into space - `kUrlLatin1` to transcode ISO-8859-1 input into UTF-8 This parser is charset agnostic. Percent encoded bytes are decoded for all fields. Returned values might contain things like NUL characters, spaces, control codes, and non-canonical encodings. Absent can be discerned from empty by checking if the pointer is set. There's no failure condition for this routine. This is a permissive parser. This doesn't normalize path segments like `.` or `..` so use IsAcceptablePath() to check for those. No restrictions are imposed beyond that which is strictly necessary for parsing. All the data that is provided will be consumed to the one of the fields. Strict conformance is enforced on some fields more than others, like scheme, since it's the most non-deterministically defined field of them all. Please note this is a URL parser, not a URI parser. Which means we support everything everything the URI spec says we should do except for the things we won't do, like tokenizing path segments into an array and then nesting another array beneath each of those for storing semicolon parameters. So this parser won't make SIP easy. What it can do is parse HTTP URLs and most URIs like data:opaque, better in fact than most things which claim to be URI parsers. IsAcceptablePath(str) → bool Returns true if path doesn't contain ".", ".." or "//" segments See isacceptablepath.c IsReasonablePath(str) → bool Returns true if path doesn't contain "." or ".." segments. See isreasonablepath.c EncodeUrl(URL) → str This function is the inverse of ParseUrl. The output will always be correctly formatted. The exception is if illegal characters are supplied in the scheme field, since there's no way of escaping those. Opaque parts are escaped as though they were paths, since many URI parsers won't understand things like an unescaped question mark in path. ParseIp(str) → int Converts IPv4 address string to integer, e.g. "1.2.3.4" → 0x01020304, or returns -1 for invalid inputs. See also FormatIp for the inverse operation. ProgramAddr(ip:int) ProgramAddr(host:str) Configures the address on which to listen. This can be called multiple times to set more than one address. If an integer is provided then it should be a word-encoded IPv4 address, such as the ones returned by ResolveIp(). If a string is provided, it will first be passed to ParseIp() to see if it's an IPv4 address. If it isn't, then a HOSTS.TXT lookup is performed, with fallback to the system-configured DNS resolution service. Please note that in MODE=tiny the HOSTS.TXT and DNS resolution isn't included, and therefore an IP must be provided. ProgramBrand(str) Changes HTTP Server header, as well as the

title on the / listing page. The brand string needs to be a UTF-8 value that's encodable as ISO-8859-1. If the brand is changed to something other than redbean, then the promotional links will be removed from the listing page too. This function should only be called from /.init.lua. ProgramCache(seconds:int) Configures Cache-Control and Expires header generation for static asset serving. A negative value will disable the headers. Zero means don't cache. Greater than zero asks public proxies and browsers to cache for a given number of seconds. This should only be called from /.init.lua. ProgramCertificate(pem:str) Same as the -C flag if called from .init.lua, e.g. ProgramCertificate(LoadAsset("/.sign.crt")) for zip loading or ProgramCertificate(Slurp("/etc/letsencrypt.lol/fullchain.pem")) for local file system only. ProgramContentType(ext:str[, contenttype:str]) → str Sets or returns content type associated with a file extension. ProgramHeader(name:str, value:str) Appends HTTP header to the header buffer for all responses (whereas SetHeader only appends a header to the current response buffer). name is case-insensitive and restricted to non-space ASCII. value is a UTF-8 string that must be encodable as ISO-8859-1. Leading and trailing whitespace is trimmed automatically. Overlong characters are canonicalized. C0 and C1 control codes are forbidden, with the exception of tab. The header buffer is independent of the payload buffer. This function disallows the setting of certain headers such as Content-Range and Date, which are abstracted by the transport layer. ProgramHeartbeatInterval([milliseconds:int]) Sets the heartbeat interval (in milliseconds). 5000ms is the default and 100ms is the minimum. If `milliseconds` is not specified, then the current interval is returned. ProgramTimeout(milliseconds:int|seconds:int) Default timeout is 60000ms. Minimal value of timeout is 10(ms). Negative values (<0) sets the keepalive in seconds. This should only be called from /.init.lua. ProgramPort(uint16) Hard-codes the port number on which to listen, which can be any number in the range 1..65535, or alternatively 0 to ask the operating system to choose a port, which may be revealed later on by GetServerAddr or the -z flag to stdout. ProgramMaxPayloadSize(int) Sets the maximum HTTP message payload size in bytes. The default is very conservatively set to 65536 so this is something many people will want to increase. This limit is enforced at the transport layer, before any Lua code is called, because right now redbean stores and forwards messages. (Use the UNIX API for raw socket streaming.) Setting this to a very high value can be useful if you're less concerned about rogue clients and would rather have your Lua code be granted more control to bounce unreasonable messages. If a value less than 1450 is supplied, it'll automatically be increased to 1450, since that's the size of ethernet frames. This function can only be called from .init.lua. ProgramMaxWorkers(int) Limits the number of workers forked by redbean. If that number is reached, the server continues polling until the number of workers is reduced or the value is updated. Setting it to 0 removes the limit (this is the default). ProgramPrivateKey(pem:str) Same as the -K flag if called from .init.lua, e.g. ProgramPrivateKey(LoadAsset("/.sign.key")) for zip loading or ProgramPrivateKey(Slurp("/etc/letsencrypt/privkey.pem")) for local file system only. ProgramRedirect(code:int, src:str, location:str) Configures fallback routing for paths which would otherwise return 404 Not Found. If code is 0 then the path is rewritten internally as an accelerated redirect. If code is 301, 302, 307, or 308 then a redirect response will be sent to the client. This should only be called from /.init.lua. ProgramSslTicketLifetime(seconds:int) Defaults to 86400 (24 hours). This may be set to ≤0 to disable SSL tickets. It's a good idea to use these since it increases handshake performance 10x and eliminates a network round trip. This function is not available in unsecure mode. ProgramSslPresharedKey(key:str, identity:str) This function can be used to enable the PSK ciphersuites which simplify SSL and enhance its performance in controlled environments. `key` may contain 1..32 bytes of random binary data and identity is usually a short plaintext string. The first time this function is called, the preshared key will be added to both the client and the server SSL configs. If it's called multiple times, then the remaining keys will be added to the server, which is useful if you want to assign separate keys to each client, each of which needs a separate identity too. If this function is called multiple times with the same identity string, then the latter call will overwrite the prior. If a preshared key is supplied and no certificates or key-signing-keys are programmed, then redbean won't bother auto-generating any serving certificates and will instead use only PSK ciphersuites. This function is not available in unsecure mode. ProgramSslFetchVerify(enabled:bool) May be used to disable the verification of certificates for remote hosts when using the Fetch() API. This function is not available in unsecure mode. ProgramSslClientVerify(enabled:bool) Enables the verification of certificates supplied by the HTTP clients that connect to your redbean. This has the same effect as the `-j` flag. Tuning this option alone does not preclude the possibility of unsecured HTTP clients, which can be disabled using ProgramSslRequired(). This function can only be called from `.init.lua`. This function is not available in unsecure mode. ProgramSslRequired(mandatory:str) Enables the blocking of HTTP so that all inbound clients and must use the TLS transport layer. This has the same effect as the `-J` flag. Fetch() is still allowed to make outbound HTTP requests. This function can only be called from `.init.lua`. This function is not available in unsecure mode. ProgramSslCiphersuite(name:str) See https://redbean.dev/ for further details. IsDaemon() → bool Returns true if -d flag was passed to redbean. ProgramUid(int) Same as the -U flag if called from .init.lua for setuid() ProgramGid(int) Same as the -G flag if called from .init.lua for setgid() ProgramDirectory(str) Same as the -D flag if called from .init.lua for overlaying local file system directories. This may be called multiple times. The first directory programmed is preferred. These currently do not show up in the index page listing. ProgramLogMessages(bool) Same as the -m flag if called from .init.lua for logging message headers only. ProgramLogBodies(bool) Same as the -b flag if called from .init.lua for logging message bodies as part of POST / PUT / etc. requests. ProgramLogPath(str) Same as the -L flag if called from .init.lua for setting the log file path on the local file system. It's created if it doesn't exist. This is called before de-escalating the user / group id. The file is opened in append only mode. If the disk runs out of space then redbean will truncate the log file if has access to change the log file after daemonizing. ProgramPidPath(str) Same as the -P flag if called from .init.lua for setting the pid file path on the local file system. It's useful for reloading daemonized redbean using `kill -HUP $(cat /var/run/redbean.pid)` or terminating redbean with `kill $(cat /var/run/redbean.pid)` which will gracefully terminate all clients. Sending the TERM signal twice will cause a forceful shutdown, which might make someone with a slow internet connection who's downloading big files unhappy. ProgramUniprocess([bool]) → bool Same as the -u flag if called from .init.lua. Can be used to configure the uniprocess mode. The current value is returned. Slurp(filename:str[, i:int[, j:int]]) ├─→ data:str └─→ nil, unix.Errno Reads all data from file the easy way. This function reads file data from local file system. Zip file assets can be accessed using the `/zip/...` prefix. `i` and `j` may be used to slice a substring in `filename`. These parameters are 1-indexed and behave consistently with Lua's string.sub() API. For example: assert(Barf('x.txt', 'abc123')) assert(assert(Slurp('x.txt', 2, 3)) == 'bc') This function is uninterruptible so `unix.EINTR` errors will be ignored. This should only be a concern if you've installed signal handlers. Use the UNIX API if you need to react to it. Barf(filename:str, data:str[, mode:int[, flags:int[, offset:int]]]) ├─→ true └─→ nil, unix.Errno Writes all data to file the easy way. This function writes to the local file system. `mode` defaults to `0644`. This parameter is ignored when `flags` doesn't have `unix.O_CREAT`. `flags` defaults to `unix.O_TRUNC | unix.O_CREAT`. `offset` is 1-indexed and may be used to overwrite arbitrary slices within a file when used in conjunction with `flags=0`. For example: assert(Barf('x.txt', 'abc123')) assert(Barf('x.txt', 'XX', 0, 0, 3)) assert(assert(Slurp('x.txt', 1, 6)) == 'abXX23') Sleep(seconds:number) Sleeps the specified number of seconds (can be fractional). The smallest interval is a microsecond. Route([host:str[, path:str]]) Instructs redbean to follow the normal HTTP serving path. This function is useful when writing an OnHttpRequest handler, since that overrides the serving path entirely. So if the handler decides it doesn't want to do anything, it can simply call this function, to hand over control back to the redbean core. By default, the host and path arguments are supplied from the resolved GetUrl value. This handler always resolves, since it will generate a 404 Not Found response if redbean couldn't find an appropriate endpoint. RouteHost([host:str[, path:str]]) → bool This is the same as Route, except it only implements the subset of request routing needed for serving virtual-hosted assets, where redbean tries to prefix the path with the hostname when looking up a file. This function returns true if the request was resolved. If it was resolved, then your OnHttpRequest request handler can still set additional headers. RoutePath([path:str]) → bool This is the same as Route, except it only implements the subset of request routing needed for serving assets. This function returns true if the request was resolved. If it was resolved, then your OnHttpRequest request handler can still set additional headers. Note that the asset needs to have "read other" permissions; otherwise this function logs a warning and returns 403 Forbidden. If this is undesirable, use GetAssetMode and ServeAsset to bypass the check. ServeAsset(path:str) Instructs redbean to serve static asset at path. This function causes what would normally happen outside a dynamic handler to happen. The asset can be sourced from either the zip or local filesystem if -D is used. This function is mutually exclusive with SetStatus and other Serve* functions. ServeError(code:int[, reason:str]) Instructs redbean to serve a boilerplate error page. This takes care of logging the error, setting the reason phrase, and adding a payload. This function is mutually exclusive with SetStatus and other Serve* functions. ServeRedirect(code:int, location:str) Instructs redbean to return the specified redirect code along with the Location header set. This function is mutually exclusive with SetStatus and other Serve* functions. SetLogLevel(level:int) Sets logger verbosity. Reasonable values for level are kLogDebug > kLogVerbose > kLogInfo > kLogWarn > kLogError > kLogFatal. This is reset at the end of the http request, so it can be used to disable access log and message logging. VisualizeControlCodes(str) → str Replaces C0 control codes and trojan source characters with descriptive UNICODE pictorial representation. This function also canonicalizes overlong encodings. C1 control codes are replaced with a JavaScript-like escape sequence. Underlong(str) → str Canonicalizes overlong encodings. Crc32(initial:int, data:str) → int Computes 32-bit CRC-32 used by zip/zlib/gzip/etc. Crc32c(initial:int, data:str) → int Computes 32-bit Castagnoli Cyclic Redundancy Check. Md5(str) → str Computes MD5 checksum, returning 16 bytes of binary. Sha1(str) → str Computes SHA1 checksum, returning 20 bytes of binary. Sha224(str) → str Computes SHA224 checksum, returning 28 bytes of binary. Sha256(str) → str Computes SHA256 checksum, returning 32 bytes of binary. Sha384(str) → str Computes SHA384 checksum, returning 48 bytes of binary. Sha512(str) → str Computes SHA512 checksum, returning 64 bytes of binary. Bsf(x:int) → int Returns position of first bit set. Passing 0 will raise an error. Same as the Intel x86 instruction BSF. Bsr(x:int) → int Returns binary logarithm of 𝑥. Passing 0 will raise an error. Same as the Intel x86 instruction BSR. Popcnt(x:int) → int Returns number of bits set in integer. Rdtsc() → int Returns CPU timestamp counter. Lemur64() → int Returns fastest pseudorandom non-cryptographic random number. This linear congruential generator passes practrand and bigcrush. Rand64() → int Returns nondeterministic pseudorandom non-cryptographic number. This linear congruential generator passes practrand and bigcrush. This generator is safe across fork(), threads, and signal handlers. Rdrand() → int Returns 64-bit hardware random integer from RDRND instruction, with automatic fallback to getrandom() if not available. Rdseed() → int Returns 64-bit hardware random integer from RDSEED instruction, with automatic fallback to RDRND and getrandom() if not available. GetCpuCount() → int Returns CPU core count or 0 if it couldn't be determined. GetCpuCore() → int Returns 0-indexed CPU core on which process is currently scheduled. GetCpuNode() → int Returns 0-indexed NUMA node on which process is currently scheduled. Decimate(str) → str Shrinks byte buffer in half using John Costella's magic kernel. This downscales data 2x using an eight-tap convolution, e.g. >: Decimate('\xff\xff\x00\x00\xff\xff\x00\x00\xff\xff\x00\x00') "\xff\x00\xff\x00\xff\x00" This is very fast if SSSE3 is available (Intel 2004+ / AMD 2011+). MeasureEntropy(data) → float Returns Shannon entropy of array. This gives you an idea of the density of information. Cryptographic random should be in the ballpark of 7.9 whereas plaintext will be more like 4.5. Deflate(uncompressed:str[, level:int]) ├─→ compressed:str └─→ nil, error:str Compresses data. >: Deflate("hello") "\xcbH\xcd\xc9\xc9\x07\x00" >: Inflate("\xcbH\xcd\xc9\xc9\x07\x00", 5) "hello" The output format is raw DEFLATE that's suitable for embedding into formats like a ZIP file. It's recommended that, like ZIP, you also store separately a Crc32() checksum in addition to the original uncompressed size. `level` is the compression level, which defaults to 7. The max is 9. Lower numbers go faster (4 for instance is a sweet spot) and higher numbers go slower but have better compression. Inflate(compressed:str, maxoutsize:int) ├─→ uncompressed:str └─→ nil, error:str Decompresses data. This function performs the inverse of Deflate(). It's recommended that you perform a Crc32() check on the output string after this function succeeds. `maxoutsize` is the uncompressed size, which should be known. However, it is permissable (although not advised) to specify some large number in which case (on success) the byte length of the output string may be less than `maxoutsize`. Benchmark(func[, count[, maxattempts]]) └─→ nanos:real, ticks:int, overhead-ticks:int, tries:int Performs microbenchmark. The first value returned is the average number of nanoseconds that `func` needed to execute. Nanoseconds are computed from RDTSC tick counts, using an approximation that's measured beforehand with the unix.clock_gettime() function. The `ticks` result is the canonical average number of clock ticks. This subroutine will subtract whatever the overhead happens to be for benchmarking a function that does nothing. This overhead value will be reported in the result. `tries` indicates if your microbenchmark needed to be repeated, possibly because your system is under load and the benchmark was preempted by the operating system, or moved to a different core. oct(int) └─→ str Formats string as octal integer literal string. If the provided value is zero, the result will be `"0"`. Otherwise the resulting value will be the zero-prefixed octal string. The result is currently modulo 2^64. Negative numbers are converted to unsigned. hex(int) └─→ str Formats string as hexadecimal integer literal string. If the provided value is zero, the result will be `"0"`. Otherwise the resulting value will be the `"0x"`-prefixed hex string. The result is currently modulo 2^64. Negative numbers are converted to unsigned. bin(int) └─→ str Formats string as binary integer literal string. If the provided value is zero, the result will be `"0"`. Otherwise the resulting value will be the `"0b"`-prefixed binary str. The result is currently modulo 2^64. Negative numbers are converted to unsigned. ResolveIp(hostname:str) ├─→ ip:uint32 └─→ nil, error:str Gets IP address associated with hostname. This function first checks if hostname is already an IP address, in which case it returns the result of `ParseIp`. Otherwise, it checks HOSTS.TXT on the local system and returns the first IPv4 address associated with hostname. If no such entry is found, a DNS lookup is performed using the system configured (e.g. /etc/resolv.conf) DNS resolution service. If the service returns multiple IN A records then only the first one is returned. The returned address is word-encoded in host endian order. For example, 1.2.3.4 is encoded as 0x01020304. The `FormatIp` function may be used to turn this value back into a string. If no IP address could be found, then nil is returned alongside a string of unspecified format describing the error. Calls to this function may be wrapped in assert() if an exception is desired. IsTrustedIp(ip:int) └─→ bool Returns true if IP address is trustworthy. If the ProgramTrustedIp() function has NOT been called then redbean will consider the networks 127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 to be trustworthy too. If ProgramTrustedIp() HAS been called at some point earlier in your redbean's lifecycle, then it'll trust the IPs and network subnets you specify instead. The network interface addresses used by the host machine are always considered trustworthy, e.g. 127.0.0.1. This may change soon, if we decide to export a GetHostIps() API which queries your NIC devices. ProgramTrustedIp(ip:int[, cidr:int]) Trusts an IP address or network. This function may be used to configure the IsTrustedIp() function which is how redbean determines if a client is allowed to send us headers like X-Forwarded-For (cf GetRemoteAddr vs. GetClientAddr) without them being ignored. Trusted IPs is also how redbean turns off token bucket rate limiting selectively, so be careful. Here's an example of how you could trust all of Cloudflare's IPs: ProgramTrustedIp(ParseIp("103.21.244.0"), 22); ProgramTrustedIp(ParseIp("103.22.200.0"), 22); ProgramTrustedIp(ParseIp("103.31.4.0"), 22); ProgramTrustedIp(ParseIp("104.16.0.0"), 13); ProgramTrustedIp(ParseIp("104.24.0.0"), 14); ProgramTrustedIp(ParseIp("108.162.192.0"), 18); ProgramTrustedIp(ParseIp("131.0.72.0"), 22); ProgramTrustedIp(ParseIp("141.101.64.0"), 18); ProgramTrustedIp(ParseIp("162.158.0.0"), 15); ProgramTrustedIp(ParseIp("172.64.0.0"), 13); ProgramTrustedIp(ParseIp("173.245.48.0"), 20); ProgramTrustedIp(ParseIp("188.114.96.0"), 20); ProgramTrustedIp(ParseIp("190.93.240.0"), 20); ProgramTrustedIp(ParseIp("197.234.240.0"), 22); ProgramTrustedIp(ParseIp("198.41.128.0"), 17); Although you might want consider trusting redbean's open source freedom embracing solution to DDOS protection instead! ProgramTokenBucket([replenish:num, cidr:int, reject:int, ignore:int, ban:int]) Enables DDOS protection. Imagine you have 2**32 buckets, one for each IP address. Each bucket can hold about 127 tokens. Every second a background worker puts one token in each bucket. When a TCP client socket is opened, it takes a token from its bucket, and then proceeds. If the bucket holds only a third of its original tokens, then redbean sends them a 429 warning. If the client ignores this warning and keeps sending requests, until there's no tokens left, then the banhammer finally comes down. function OnServerStart() ProgramTokenBucket() ProgramTrustedIp(ParseIp('x.x.x.x'), 32) assert(unix.setrlimit(unix.RLIMIT_NPROC, 1000, 1000)) end This model of network rate limiting generously lets people "burst" a tiny bit. For example someone might get a strong craving for content and smash the reload button in Chrome 64 times in a fow seconds. But since the client only get 1 new token per second, they'd better cool their heels for a few minutes after doing that. This amount of burst can be altered by choosing the `reject` / `ignore` / `ban` threshold arguments. For example, if the `reject` parameter is set to 126 then no bursting is allowed, which probably isn't a good idea. redbean is programmed to acquire a token immediately after accept() is called from the main server process, which is well before fork() or read() or any Lua code happens. redbean then takes action, based on the token count, which can be accept / reject / ignore / ban. If redbean determines a ban is warrented, then 4-byte datagram is sent to the unix domain socket `/var/run/blackhole.sock` which should be operated using the blackholed program we distribute separately. The trick redbean uses on Linux for example is insert rules in your raw prerouting table. redbean is very fast at the application layer so the biggest issue we've encountered in production is are kernels themselves, and programming the raw prerouting table dynamically is how we solved that. `replenish` is the number of times per second a token should be added to each bucket. The default value is 1 which means one token is granted per second to all buckets. The minimum value is 1/3600 which means once per hour. The maximum value for this setting is 1e6, which means once every microsecond. `cidr` is the specificity of judgement. Since creating 2^32 buckets would need 4GB of RAM, redbean defaults this value to 24 which means filtering applies to class c network blocks (i.e. x.x.x.*), and your token buckets only take up 2^24 bytes of RAM (16MB). This can be set to any number on the inclusive interval [8,32], where having a lower number means you use less ram/cpu, but splash damage applies more to your clients; whereas higher numbers means more ram/cpu usage, while ensuring rate limiting only applies to specific compromised actors. `reject` is the token count or treshold at which redbean should send 429 Too Many Request warnings to the client. Permitted values can be anywhere between -1 and 126 inclusively. The default value is 30 and -1 means disable to disable (assuming AcquireToken() will be used). `ignore` is the token count or treshold, at which redbean should try simply ignoring clients and close the connection without logging any kind of warning, and without sending any response. The default value for this setting is `MIN(reject / 2, 15)`. This must be less than or equal to the `reject` setting. Allowed values are [-1,126] where you can use -1 as a means of disabling `ignore`. `ban` is the token count at which redbean should report IP addresses to the blackhole daemon via a unix-domain socket datagram so they'll get banned in the kernel routing tables. redbean's default value for this setting is `MIN(ignore / 10, 1)`. Permitted values are [-1,126] where -1 may be used as a means of disabling the `ban` feature. This function throws an exception if the constraints described above are not the case. Warnings are logged should redbean fail to connect to the blackhole daemon, assuming it hasn't been disabled. It's safe to use load balancing tools when banning is enabled, since you can't accidentally ban your own network interface addresses, loopback ips, or ProgramTrustedIp() addresses where these rate limits don't apply. It's assumed will be called from the .init.lua global scope although it could be used in interpreter mode, or from a forked child process in which case the only processes that'll have ability to use it will be that same process, and any descendent processes. This function is only able to be called once. This feature is not available in unsecure mode. AcquireToken([ip:uint32]) └─→ int8 Atomically acquires token. This routine atomically acquires a single token for an `ip` address. The return value is the token count before the subtraction happened. No action is taken based on the count, since the caller will decide. `ip` should be an IPv4 address and this defaults to GetClientAddr(), although other interpretations of its meaning are possible. Your token buckets are stored in shared memory so this can be called from multiple forked processes. which operate on the same values. CountTokens([ip:uint32]) └─→ int8 Counts number of tokens in bucket. This function is the same as AcquireToken() except no subtraction is performed, i.e. no token is taken. `ip` should be an IPv4 address and this defaults to GetClientAddr(), although other interpretations of its meaning are possible. Blackhole(ip:uint32) └─→ bool Sends IP address to blackholed service. ProgramTokenBucket() needs to be called beforehand. The default settings will blackhole automatically, during the accept() loop based on the banned threshold. However if your Lua code calls AcquireToken() manually, then you'll need this function to take action on the returned values. This function returns true if a datagram could be sent sucessfully. Otherwise false is returned, which can happen if blackholed isn't running, or if a lot of processes are sending messages to it and the operation would have blocked. It's assumed that the blackholed service is running locally in the background. ──────────────────────────────────────────────────────────────────────────────── CONSTANTS kLogDebug Integer for debug logging level. See Log. kLogVerbose Integer for verbose logging level, which is less than kLogDebug. kLogInfo Integer for info logging level, which is less than kLogVerbose. kLogWarn Integer for warn logging level, which is less than kLogVerbose. kLogError Integer for error logging level, which is less than kLogWarn. kLogFatal Integer for fatal logging level, which is less than kLogError. Logging anything at this level will result in a backtrace and process exit. ──────────────────────────────────────────────────────────────────────────────── LSQLITE3 MODULE Please refer to the LuaSQLite3 Documentation. For example, you could put the following in your /.init.lua file: sqlite3 = require "lsqlite3" db = sqlite3.open_memory() db:exec[[ CREATE TABLE test ( id INTEGER PRIMARY KEY, content TEXT ); INSERT INTO test (content) VALUES ('Hello World'); INSERT INTO test (content) VALUES ('Hello Lua'); INSERT INTO test (content) VALUES ('Hello Sqlite3'); ]] Then, your Lua server pages or OnHttpRequest handler may perform SQL queries by accessing the db global. The performance is good too, at about 400k qps. for row in db:nrows("SELECT * FROM test") do Write(row.id.." "..row.content.."
") end redbean supports a subset of what's defined in the upstream LuaSQLite3 project. Most of the unsupported APIs relate to pointers and database notification hooks. ──────────────────────────────────────────────────────────────────────────────── RE MODULE This module exposes an API for POSIX regular expressions which enable you to validate input, search for substrings, extract pieces of strings, etc. Here's a usage example: # Example IPv4 Address Regular Expression (see also ParseIP) p = re.compile([[^([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})$]]) m,a,b,c,d = assert(p:search(𝑠)) if m then print("ok", tonumber(a), tonumber(b), tonumber(c), tonumber(d)) else print("not ok") end re.search(regex:str, text:str[, flags:int]) ├─→ match:str[, group1:str, ...] └─→ nil, re.Errno Searches for regular expression match in text. This is a shorthand notation roughly equivalent to: preg = re.compile(regex) patt = preg:search(re, text) `flags` defaults to zero and may have any of: - `re.BASIC` - `re.ICASE` - `re.NEWLINE` - `re.NOSUB` - `re.NOTBOL` - `re.NOTEOL` This has exponential complexity. Please use re.compile() to compile your regular expressions once from `/.init.lua`. This API exists for convenience. This isn't recommended for prod. This uses POSIX extended syntax by default. re.compile(regex:str[, flags:int]) → re.Regex ├─→ preg:re.Regex └─→ nil, re.Errno Compiles regular expression. `flags` defaults to zero and may have any of: - `re.BASIC` - `re.ICASE` - `re.NEWLINE` - `re.NOSUB` This has an O(2^𝑛) cost. Consider compiling regular expressions once from your `/.init.lua` file. If `regex` is an untrusted user value, then `unix.setrlimit` should be used to impose cpu and memory quotas for security. This uses POSIX extended syntax by default. ──────────────────────────────────────────────────────────────────────────────── RE REGEX OBJECT re.Regex:search(text:str[, flags:int]) ├─→ match:str[, group1:str, ...] └─→ nil, re.Errno Executes precompiled regular expression. Returns nothing (nil) if the pattern doesn't match anything. Otherwise it pushes the matched substring and any parenthesis-captured values too. Flags may contain re.NOTBOL or re.NOTEOL to indicate whether or not text should be considered at the start and/or end of a line. `flags` defaults to zero and may have any of: - `re.NOTBOL` - `re.NOTEOL` This has an O(𝑛) cost. ──────────────────────────────────────────────────────────────────────────────── RE ERRNO OBJECT re.Errno:errno() └─→ errno:int Returns regex error number. re.Errno:doc() └─→ description:str Returns English string describing error code. re.Errno:__tostring() └─→ str Delegates to re.Errno:doc() ──────────────────────────────────────────────────────────────────────────────── RE ERRORS re.NOMATCH No match re.BADPAT Invalid regex re.ECOLLATE Unknown collating element re.ECTYPE Unknown character class name re.EESCAPE Trailing backslash re.ESUBREG Invalid back reference re.EBRACK Missing `]` re.EPAREN Missing `)` re.EBRACE Missing `}` re.BADBR Invalid contents of `{}` re.ERANGE Invalid character range. re.ESPACE Out of memory re.BADRPT Repetition not preceded by valid expression ──────────────────────────────────────────────────────────────────────────────── RE FLAGS re.BASIC Use this flag if you prefer the default POSIX regex syntax. We use extended regex notation by default. For example, an extended regular expression for matching an IP address might look like ([0-9]*)\.([0-9]*)\.([0-9]*)\.([0-9]*) whereas with basic syntax it would look like \([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\). This flag may only be used with re.compile and re.search. re.ICASE Use this flag to make your pattern case ASCII case-insensitive. This means [a-z] will mean the same thing as [A-Za-z]. This flag may only be used with re.compile and re.search. re.NEWLINE Use this flag to change the handling of NEWLINE (\x0a) characters. When this flag is set, (1) a NEWLINE shall not be matched by a "." or any form of a non-matching list, (2) a "^" shall match the zero-length string immediately after a NEWLINE (regardless of re.NOTBOL), and (3) a "$" shall match the zero-length string immediately before a NEWLINE (regardless of re.NOTEOL). re.NOSUB Causes re.search to only report success and failure. This is reported via the API by returning empty string for success. This flag may only be used with re.compile and re.search. re.NOTBOL The first character of the string pointed to by string is not the beginning of the line. This flag may only be used with re.search and re.Regex:search. re.NOTEOL The last character of the string pointed to by string is not the end of the line. This flag may only be used with re.search and re.Regex:search. ──────────────────────────────────────────────────────────────────────────────── PATH MODULE The path module may be used to manipulate unix paths. Note that we use unix paths on Windows. For example, if you have a path like C:\foo\bar then it should be /c/foo/bar with redbean. It should also be noted the unix module is more permissive when using Windows paths, where translation to win32 is very light. path.dirname(str) └─→ str Strips final component of path, e.g. path │ dirname ─────────────────── . │ . .. │ . / │ / usr │ . /usr/ │ / /usr/lib │ /usr /usr/lib/ │ /usr path.basename(path:str) └─→ str Returns final component of path, e.g. path │ basename ───────────────────── . │ . .. │ .. / │ / usr │ usr /usr/ │ usr /usr/lib │ lib /usr/lib/ │ lib path.join(str, ...) └─→ str Concatenates path components, e.g. x │ y │ joined ───────────────────────────────── / │ / │ / /usr │ lib │ /usr/lib /usr/ │ lib │ /usr/lib /usr/lib │ /lib │ /lib You may specify 1+ arguments. Specifying no arguments will raise an error. If nil arguments are specified, then they're skipped over. If exclusively nil arguments are passed, then nil is returned. Empty strings behave similarly to nil, but unlike nil may coerce a trailing slash. path.exists(path:str) └─→ bool Returns true if path exists. This function is inclusive of regular files, directories, and special files. Symbolic links are followed are resolved. On error, false is returned. path.isfile(path:str) └─→ bool Returns true if path exists and is regular file. Symbolic links are not followed. On error, false is returned. path.isdir(path:str) └─→ bool Returns true if path exists and is directory. Symbolic links are not followed. On error, false is returned. path.islink(path:str) └─→ bool Returns true if path exists and is symbolic link. Symbolic links are not followed. On error, false is returned. ──────────────────────────────────────────────────────────────────────────────── MAXMIND MODULE This module may be used to get city/country/asn/etc from IPs, e.g. -- .init.lua maxmind = require 'maxmind' asndb = maxmind.open('/usr/local/share/maxmind/GeoLite2-ASN.mmdb') -- request handler as = asndb:lookup(GetRemoteAddr()) if as then asnum = as:get('autonomous_system_number') asorg = as:get('autonomous_system_organization') Write(EscapeHtml(asnum)) Write(' ') Write(EscapeHtml(asorg)) end For further details, please see maxmind.lua in redbean-demo.com. ──────────────────────────────────────────────────────────────────────────────── FINGER MODULE This is an experimental module that, like the maxmind module, gives you insight into what kind of device is connecting to your redbean. This module can help you protect your redbean because it provides tools for identifying clients that misrepresent themselves. For example the User-Agent header might report itself as a Windows computer when the SYN packet says it's a Linux computer. function OnServerListen(fd, ip, port) unix.setsockopt(fd, unix.SOL_TCP, unix.TCP_SAVE_SYN, true) return false end function OnClientConnection(ip, port, serverip, serverport) fd = GetClientFd() syn = unix.getsockopt(fd, unix.SOL_TCP, unix.TCP_SAVED_SYN) end function OnHttpRequest() Log(kLogInfo, "client is running %s and reports %s" % { finger.GetSynFingerOs(finger.FingerSyn(syn)), GetHeader('User-Agent')}) Route() end The following functions are provided. finger.FingerSyn(syn_packet_bytes:str) ├─→ synfinger:uint32 └─→ nil, error:str Fingerprints IP+TCP SYN packet. This returns a hash-like magic number that reflects the SYN packet structure, e.g. ordering of options, maximum segment size, etc. We make no guarantees this hashing algorithm won't change as we learn more about the optimal way to fingerprint, so be sure to save your syn packets too if you're using this feature, in case they need to be rehashed in the future. This function is nil/error propagating. finger.GetSynFingerOs(synfinger:uint32) ├─→ osname:str └─→ nil, error:str Fingerprints IP+TCP SYN packet. If `synfinger` is a known hard-coded magic number, then one of the following strings may be returned: - `"LINUX"` - `"WINDOWS"` - `"XNU"` - `"NETBSD"` - `"FREEBSD"` - `"OPENBSD"` If this function returns nil, then one thing you can do to help is file an issue and share with us your SYN packet specimens. The way we prefer to receive them is in EncodeLua(syn_packet_bytes) format along with details on the operating system which you must know. finger.DescribeSyn(syn_packet_bytes:str) ├─→ description:str └─→ nil, error:str Describes IP+TCP SYN packet. The layout looks as follows: TTL:OPTIONS:WSIZE:MSS The `TTL`, `WSIZE`, and `MSS` fields are unsigned decimal fields. The `OPTIONS` field communicates the ordering of the commonly used subset of tcp options. The following character mappings are defined. TCP options not on this list will be ignored. - E: End of Option list - N: No-Operation - M: Maxmimum Segment Size - K: Window Scale - O: SACK Permitted - A: SACK - e: Echo (obsolete) - r: Echo reply (obsolete) - T: Timestamps This function is nil/error propagating. ──────────────────────────────────────────────────────────────────────────────── ARGON2 MODULE This module implements a password hashing algorithm based on blake2b that won the Password Hashing Competition. It can be used to securely store user passwords in your SQLite database, in a way that destroys the password, but can be verified by regenerating the hash again the next time the user logs in. Destroying the password is important, since if your database is compromised, the bad guys won't be able to use rainbow tables to recover the plain text of the passwords. Argon2 achieves this security by being expensive to compute. Care should be taken in choosing parameters, since an HTTP endpoint that uses Argon2 can just as easily become a denial of service vector. For example, you may want to consider throttling your login endpoint. argon2.hash_encoded(pass:str, salt:str[, config:table]) ├─→ ascii:str └─→ nil, error:str Hashes password. This is consistent with the README of the reference implementation: >: assert(argon2.hash_encoded("password", "somesalt", { variant = argon2.variants.argon2_i, m_cost = 65536, hash_len = 24, parallelism = 4, t_cost = 2, })) "$argon2i$v=19$m=65536,t=2,p=4$c29tZXNhbHQ$RdescudvJCsgt3ub+b+dWRWJTmaaJObG" `pass` is the secret value to be encoded. `salt` is a nonce value used to hash the string. `config.m_cost` is the memory hardness in kibibytes, which defaults to 4096 (4 mibibytes). It's recommended that this be tuned upwards. `config.t_cost` is the number of iterations, which defaults to 3. `config.parallelism` is the parallelism factor, which defaults to 1. `config.hash_len` is the number of desired bytes in hash output, which defaults to 32. `config.variant` may be: - `argon2.variants.argon2_id` blend of other two methods [default] - `argon2.variants.argon2_i` maximize resistance to side-channel attacks - `argon2.variants.argon2_d` maximize resistance to gpu cracking attacks argon2.verify(encoded:str, pass:str) ├─→ ok:bool └─→ nil, error:str Verifies password, e.g. >: argon2.verify( "$argon2i$v=19$m=65536,t=2," .. "p=4$c29tZXNhbHQ$RdescudvJCsgt3ub+b+dWRWJTmaaJObG", "password") true ──────────────────────────────────────────────────────────────────────────────── UNIX MODULE This module exposes the low-level System Five system call interface. This module works on all supported platforms, including Windows NT. unix.open(path:str, flags:int[, mode:int[, dirfd:int]]) ├─→ fd:int └─→ nil, unix.Errno Opens file. Returns a file descriptor integer that needs to be closed, e.g. fd = assert(unix.open("/etc/passwd", unix.O_RDONLY)) print(unix.read(fd)) unix.close(fd) `flags` should have one of: - `O_RDONLY`: open for reading (default) - `O_WRONLY`: open for writing - `O_RDWR`: open for reading and writing The following values may also be OR'd into `flags`: - `O_CREAT` create file if it doesn't exist - `O_TRUNC` automatic ftruncate(fd,0) if exists - `O_CLOEXEC` automatic close() upon execve() - `O_EXCL` exclusive access (see below) - `O_APPEND` open file for append only - `O_NONBLOCK` asks read/write to fail with EAGAIN rather than block - `O_DIRECT` it's complicated (not supported on Apple and OpenBSD) - `O_DIRECTORY` useful for stat'ing (hint on UNIX but required on NT) - `O_NOFOLLOW` fail if it's a symlink (zero on Windows) - `O_DSYNC` it's complicated (zero on non-Linux/Apple) - `O_RSYNC` it's complicated (zero on non-Linux/Apple) - `O_PATH` it's complicated (zero on non-Linux) - `O_VERIFY` it's complicated (zero on non-FreeBSD) - `O_SHLOCK` it's complicated (zero on non-BSD) - `O_EXLOCK` it's complicated (zero on non-BSD) - `O_NOATIME` don't record access time (zero on non-Linux) - `O_RANDOM` hint random access intent (zero on non-Windows) - `O_SEQUENTIAL` hint sequential access intent (zero on non-Windows) - `O_COMPRESSED` ask fs to abstract compression (zero on non-Windows) - `O_INDEXED` turns on that slow performance (zero on non-Windows) There are three regular combinations for the above flags: - `O_RDONLY`: Opens existing file for reading. If it doesn't exist then nil is returned and errno will be `ENOENT` (or in some other cases `ENOTDIR`). - `O_WRONLY|O_CREAT|O_TRUNC`: Creates file. If it already exists, then the existing copy is destroyed and the opened file will start off with a length of zero. This is the behavior of the traditional creat() system call. - `O_WRONLY|O_CREAT|O_EXCL`: Create file only if doesn't exist already. If it does exist then `nil` is returned along with `errno` set to `EEXIST`. `dirfd` defaults to to `unix.AT_FDCWD` and may optionally be set to a directory file descriptor to which `path` is relative. Returns `ENOENT` if `path` doesn't exist. Returns `ENOTDIR` if `path` contained a directory component that wasn't a directory. unix.close(fd:int) ├─→ true └─→ nil, unix.Errno Closes file descriptor. This function should never be called twice for the same file descriptor, regardless of whether or not an error happened. The file descriptor is always gone after close is called. So it technically always succeeds, but that doesn't mean an error should be ignored. For example, on NFS a close failure could indicate data loss. Closing does not mean that scheduled i/o operations have been completed. You'd need to use fsync() or fdatasync() beforehand to ensure that. You shouldn't need to do that normally, because our close implementation guarantees a consistent view, since on systems where it isn't guaranteed (like Windows) close will implicitly sync. File descriptors are automatically closed on exit(). Returns `EBADF` if `fd` wasn't valid. Returns `EINTR` possibly maybe. Returns `EIO` if an i/o error occurred. unix.read(fd:int[, bufsiz:str[, offset:int]]) ├─→ data:str └─→ nil, unix.Errno Reads from file descriptor. This function returns empty string on end of file. The exception is if `bufsiz` is zero, in which case an empty returned string means the file descriptor works. unix.write(fd:int, data:str[, offset:int]) ├─→ wrotebytes:int └─→ nil, unix.Errno Writes to file descriptor. unix.exit([exitcode:int]) └─→ ⊥ Invokes `_Exit(exitcode)` on the process. This will immediately halt the current process. Memory will be freed. File descriptors will be closed. Any open connections it owns will be reset. This function never returns. unix.environ() └─→ {str,...} Returns raw environment variables. This allocates and constructs the C/C++ `environ` variable as a Lua table consisting of string keys and string values. This data structure preserves casing. On Windows NT, by convention, environment variable keys are treated in a case-insensitive way. It is the responsibility of the caller to consider this. This data structure preserves valueless variables. It's possible on both UNIX and Windows to have an environment variable without an equals, even though it's unusual. This data structure preserves duplicates. For example, on Windows, there's some irregular uses of environment variables such as how the command prompt inserts multiple environment variables with empty string as keys, for its internal bookkeeping. unix.fork() ├─┬─→ 0 │ └─→ childpid:int └─→ nil, unix.Errno Creates a new process mitosis style. This system call returns twice. The parent process gets the nonzero pid. The child gets zero. Here's a simple usage example of creating subprocesses, where we fork off a child worker from a main process hook callback to do some independent chores, such as sending an HTTP request back to redbean. -- as soon as server starts, make a fetch to the server -- then signal redbean to shutdown when fetch is complete local onServerStart = function() if assert(unix.fork()) == 0 then local ok, headers, body = Fetch('http://127.0.0.1:8080/test') unix.kill(unix.getppid(), unix.SIGTERM) unix.exit(0) end end OnServerStart = onServerStart We didn't need to use wait() here, because (a) we want redbean to go back to what it was doing before as the Fetch() completes, and (b) redbean's main process already has a zombie collector. However it's a moot point, since once the fetch is done, the child process then asks redbean to gracefully shutdown by sending SIGTERM its parent. This is actually a situation where we *must* use fork, because the purpose of the main redbean process is to call accept() and create workers. So if we programmed redbean to use the main process to send a blocking request to itself instead, then redbean would deadlock and never be able to accept() the client. While deadlocking is an extreme example, the truth is that latency issues can crop up for the same reason that just cause jitter instead, and as such, can easily go unnoticed. For example, if you do something that takes longer than a few milliseconds from inside your redbean heartbeat, then that's a few milliseconds in which redbean is no longer concurrent, and tail latency is being added to its ability to accept new connections. fork() does a great job at solving this. If you're not sure how long something will take, then when in doubt, fork off a process. You can then report its completion to something like SQLite. Redbean makes having lots of processes cheap. On Linux they're about as lightweight as what heavyweight environments call greenlets. You can easily have 10,000 Redbean workers on one PC. Here's some benchmarks for fork() performance across platforms: Linux 5.4 fork l: 97,200𝑐 31,395𝑛𝑠 [metal] FreeBSD 12 fork l: 236,089𝑐 78,841𝑛𝑠 [vmware] Darwin 20.6 fork l: 295,325𝑐 81,738𝑛𝑠 [metal] NetBSD 9 fork l: 5,832,027𝑐 1,947,899𝑛𝑠 [vmware] OpenBSD 6.8 fork l: 13,241,940𝑐 4,422,103𝑛𝑠 [vmware] Windows10 fork l: 18,802,239𝑐 6,360,271𝑛𝑠 [metal] One of the benefits of using fork() is it creates an isolation barrier between the different parts of your app. This can lead to enhanced reliability and security. For example, redbean uses fork so it can wipe your ssl keys from memory before handing over control to request handlers that process untrusted input. It also ensures that if your Lua app crashes, it won't take down the server as a whole. Hence it should come as no surprise that fork() would go slower on operating systems that have more security features. So depending on your use case, you can choose the operating system that suits you. unix.commandv(prog:str) ├─→ path:str └─→ nil, unix.Errno Performs `$PATH` lookup of executable. unix = require 'unix' prog = assert(unix.commandv('ls')) unix.execve(prog, {prog, '-hal', '.'}, {'PATH=/bin'}) unix.exit(127) We automatically suffix `.com` and `.exe` for all platforms when path searching. By default, the current directory is not on the path. If `prog` is an absolute path, then it's returned as-is. If `prog` contains slashes then it's not path searched either and will be returned if it exists. unix.execve(prog:str[, args:List<*>, env:List<*>]) └─→ nil, unix.Errno Exits current process, replacing it with a new instance of the specified program. `prog` needs to be an absolute path, see commandv(). `env` defaults to to the current `environ`. Here's a basic usage example: unix.execve("/bin/ls", {"/bin/ls", "-hal"}, {"PATH=/bin"}) unix.exit(127) `prog` needs to be the resolved pathname of your executable. You can use commandv() to search your `PATH`. `args` is a string list table. The first element in `args` should be `prog`. Values are coerced to strings. This parameter defaults to `{prog}`. `env` is a string list table. Values are coerced to strings. No ordering requirement is imposed. By convention, each string has its key and value divided by an equals sign without spaces. If this parameter is not specified, it'll default to the C/C++ `environ` variable which is inherited from the shell that launched redbean. It's the responsibility of the user to supply a sanitized environ when spawning untrusted processes. execve() is normally called after fork() returns 0. If that isn't the case, then your redbean worker will be destroyed. This function never returns on success. `EAGAIN` is returned if you've enforced a max number of processes using `setrlimit(RLIMIT_NPROC)`. unix.dup(oldfd:int[, newfd:int[, flags:int[, lowest:int]]]) ├─→ newfd:int └─→ nil, unix.Errno Duplicates file descriptor. `newfd` may be specified to choose a specific number for the new file descriptor. If it's already open, then the preexisting one will be silently closed. `EINVAL` is returned if `newfd` equals `oldfd`. `flags` can have `O_CLOEXEC` which means the returned file descriptors will be automatically closed upon execve(). `lowest` defaults to zero and defines the lowest numbered file descriptor that's acceptable to use. If `newfd` is specified then `lowest` is ignored. For example, if you wanted to duplicate standard input, then: stdin2 = assert(unix.dup(0, nil, unix.O_CLOEXEC, 3)) Will ensure that, in the rare event standard output or standard error are closed, you won't accidentally duplicate standard input to those numbers. unix.pipe([flags:int]) ├─→ reader:int, writer:int └─→ nil, unix.Errno Creates fifo which enables communication between processes. `flags` may have any combination (using bitwise OR) of: - `O_CLOEXEC`: Automatically close file descriptor upon execve() - `O_NONBLOCK`: Request `EAGAIN` be raised rather than blocking - `O_DIRECT`: Enable packet mode w/ atomic reads and writes, so long as they're no larger than `PIPE_BUF` (guaranteed to be 512+ bytes) with support limited to Linux, Windows NT, FreeBSD, and NetBSD. Returns two file descriptors: one for reading and one for writing. Here's an example of how pipe(), fork(), dup(), etc. may be used to serve an HTTP response containing the output of a subprocess. local unix = require "unix" ls = assert(unix.commandv("ls")) reader, writer = assert(unix.pipe()) if assert(unix.fork()) == 0 then unix.close(1) unix.dup(writer) unix.close(writer) unix.close(reader) unix.execve(ls, {ls, "-Shal"}) unix.exit(127) else unix.close(writer) SetHeader('Content-Type', 'text/plain') while true do data, err = unix.read(reader) if data then if data ~= "" then Write(data) else break end elseif err:errno() ~= EINTR then Log(kLogWarn, tostring(err)) break end end assert(unix.close(reader)) assert(unix.wait()) end unix.wait([pid:int[, options:int]]) ├─→ pid:int, wstatus:int, unix.Rusage └─→ nil, unix.Errno Waits for subprocess to terminate. `pid` defaults to `-1` which means any child process. Setting `pid` to `0` is equivalent to `-getpid()`. If `pid < -1` then that means wait for any pid in the process group `-pid`. Then lastly if `pid > 0` then this waits for a specific process id Options may have `WNOHANG` which means don't block, check for the existence of processes that are already dead (technically speaking zombies) and if so harvest them immediately. Returns the process id of the child that terminated. In other cases, the returned `pid` is nil and `errno` is non-nil. The returned `wstatus` contains information about the process exit status. It's a complicated integer and there's functions that can help interpret it. For example: -- wait for zombies -- traditional technique for SIGCHLD handlers while true do pid, status = unix.wait(-1, unix.WNOHANG) if pid then if unix.WIFEXITED(status) then print('child', pid, 'exited with', unix.WEXITSTATUS(status)) elseif unix.WIFSIGNALED(status) then print('child', pid, 'crashed with', unix.strsignal(unix.WTERMSIG(status))) end elseif status:errno() == unix.ECHILD then Log(kLogDebug, 'no more zombies') break else Log(kLogWarn, tostring(err)) break end end unix.WIFEXITED(wstatus:int) └─→ bool Returns true if process exited cleanly. unix.WEXITSTATUS(wstatus:int) └─→ exitcode:uint8 Returns code passed to exit() assuming `WIFEXITED(wstatus)` is true. unix.WIFSIGNALED(wstatus:int) └─→ bool Returns true if process terminated due to a signal. unix.WTERMSIG(wstatus:int) └─→ sig:uint8 Returns signal that caused process to terminate assuming `WIFSIGNALED(wstatus)` is true. unix.getpid() └─→ pid:int Returns process id of current process. This function does not fail. unix.getppid() └─→ pid:int Returns process id of parent process. This function does not fail. unix.kill(pid:int, sig:int) ├─→ true └─→ nil, unix.Errno Sends signal to process(es). The impact of this action can be terminating the process, or interrupting it to request something happen. `pid` can be: - `pid > 0` signals one process by id - `== 0` signals all processes in current process group - `-1` signals all processes possible (except init) - `< -1` signals all processes in -pid process group `sig` can be: - `0` checks both if pid exists and we can signal it - `SIGINT` sends ctrl-c keyboard interrupt - `SIGQUIT` sends backtrace and exit signal - `SIGTERM` sends shutdown signal - etc. Windows NT only supports the kill() signals required by the ANSI C89 standard, which are `SIGINT` and `SIGQUIT`. All other signals on the Windows platform that are sent to another process via kill() will be treated like `SIGKILL`. unix.raise(sig:int) ├─→ rc:int └─→ nil, unix.Errno Triggers signal in current process. This is pretty much the same as `kill(getpid(), sig)`. unix.access(path:str, how:int[, flags:int[, dirfd:int]]) ├─→ true └─→ nil, unix.Errno Checks if effective user of current process has permission to access file. `how` can be `R_OK`, `W_OK`, `X_OK`, or `F_OK` to check for read, write, execute, and existence respectively. `flags` may have any of: - `AT_SYMLINK_NOFOLLOW`: do not follow symbolic links. unix.mkdir(path:str[, mode:int[, dirfd:int]]) ├─→ true └─→ nil, unix.Errno Makes directory. `path` is the path of the directory you wish to create. `mode` is octal permission bits, e.g. `0755`. Fails with `EEXIST` if `path` already exists, whether it be a directory or a file. Fails with `ENOENT` if the parent directory of the directory you want to create doesn't exist. For making `a/really/long/path/` consider using makedirs() instead. Fails with `ENOTDIR` if a parent directory component existed that wasn't a directory. Fails with `EACCES` if the parent directory doesn't grant write permission to the current user. Fails with `ENAMETOOLONG` if the path is too long. unix.makedirs(path:str[, mode:int]) ├─→ true └─→ nil, unix.Errno Makes directories. Unlike mkdir() this convenience wrapper will automatically create parent parent directories as needed. If the directory already exists then, unlike mkdir() which returns EEXIST, the makedirs() function will return success. `path` is the path of the directory you wish to create. `mode` is octal permission bits, e.g. `0755`. unix.chdir(path:str) ├─→ true └─→ nil, unix.Errno Changes current directory to `path`. unix.unlink(path:str[, dirfd:int]) ├─→ true └─→ nil, unix.Errno Removes file at `path`. If `path` refers to a symbolic link, the link is removed. Returns `EISDIR` if `path` refers to a directory. See rmdir(). unix.rmdir(path:str[, dirfd:int]) ├─→ true └─→ nil, unix.Errno Removes empty directory at `path`. Returns `ENOTDIR` if `path` isn't a directory, or a path component in `path` exists yet wasn't a directory. unix.rename(oldpath:str, newpath:str[, olddirfd:int, newdirfd:int]) ├─→ true └─→ nil, unix.Errno Renames file or directory. unix.link(existingpath:str, newpath:str[, flags:int[, olddirfd, newdirfd]]) ├─→ true └─→ nil, unix.Errno Creates hard link, so your underlying inode has two names. unix.symlink(target:str, linkpath:str[, newdirfd:int]) ├─→ true └─→ nil, unix.Errno Creates symbolic link. On Windows NT a symbolic link is called a "reparse point" and can only be created from an administrator account. Your redbean will automatically request the appropriate permissions. unix.readlink(path:str[, dirfd:int]) ├─→ content:str └─→ nil, unix.Errno Reads contents of symbolic link. Note that broken links are supported on all platforms. A symbolic link can contain just about anything. It's important to not assume that `content` will be a valid filename. On Windows NT, this function transliterates `\` to `/` and furthermore prefixes `//?/` to WIN32 DOS-style absolute paths, thereby assisting with simple absolute filename checks in addition to enabling one to exceed the traditional 260 character limit. unix.realpath(path:str) ├─→ path:str └─→ nil, unix.Errno Returns absolute path of filename, with `.` and `..` components removed, and symlinks will be resolved. unix.utimensat(path[, asecs, ananos, msecs, mnanos[, dirfd[, flags]]]) ├─→ 0 └─→ nil, unix.Errno Changes access and/or modified timestamps on file. `path` is a string with the name of the file. The `asecs` and `ananos` parameters set the access time. If they're none or nil, the current time will be used. The `msecs` and `mnanos` parameters set the modified time. If they're none or nil, the current time will be used. The nanosecond parameters (`ananos` and `mnanos`) must be on the interval [0,1000000000) or `unix.EINVAL` is raised. On XNU this is truncated to microsecond precision. On Windows NT, it's truncated to hectonanosecond precision. These nanosecond parameters may also be set to one of the following special values: - `unix.UTIME_NOW`: Fill this timestamp with current time. This feature is not available on old versions of Linux, e.g. RHEL5. - `unix.UTIME_OMIT`: Do not alter this timestamp. This feature is not available on old versions of Linux, e.g. RHEL5. `dirfd` is a file descriptor integer opened with `O_DIRECTORY` that's used for relative path names. It defaults to `unix.AT_FDCWD`. `flags` may have have any of the following flags bitwise or'd - `AT_SYMLINK_NOFOLLOW`: Do not follow symbolic links. This makes it possible to edit the timestamps on the symbolic link itself, rather than the file it points to. unix.futimens(fd:int[, asecs, ananos, msecs, mnanos]) ├─→ 0 └─→ nil, unix.Errno Changes access and/or modified timestamps on file descriptor. `fd` is the file descriptor of a file opened with `unix.open`. The `asecs` and `ananos` parameters set the access time. If they're none or nil, the current time will be used. The `msecs` and `mnanos` parameters set the modified time. If they're none or nil, the current time will be used. The nanosecond parameters (`ananos` and `mnanos`) must be on the interval [0,1000000000) or `unix.EINVAL` is raised. On XNU this is truncated to microsecond precision. On Windows NT, it's truncated to hectonanosecond precision. These nanosecond parameters may also be set to one of the following special values: - `unix.UTIME_NOW`: Fill this timestamp with current time. - `unix.UTIME_OMIT`: Do not alter this timestamp. This system call is currently not available on very old versions of Linux, e.g. RHEL5. unix.chown(path:str, uid:int, gid:int[, flags:int[, dirfd:int]]) ├─→ true └─→ nil, unix.Errno Changes user and group on file. Returns `ENOSYS` on Windows NT. unix.chmod(path:str, mode:int[, flags:int[, dirfd:int]]) ├─→ true └─→ nil, unix.Errno Changes mode bits on file. On Windows NT the chmod system call only changes the read-only status of a file. unix.getcwd() ├─→ path:str └─→ nil, unix.Errno Returns current working directory. On Windows NT, this function transliterates `\` to `/` and furthermore prefixes `//?/` to WIN32 DOS-style absolute paths, thereby assisting with simple absolute filename checks in addition to enabling one to exceed the traditional 260 character limit. unix.rmrf(path:str) ├─→ true └─→ nil, unix.Errno Recursively removes filesystem path. Like unix.makedirs() this function isn't actually a system call but rather is a Libc convenience wrapper. It's intended to be equivalent to using the UNIX shell's `rm -rf path` command. `path` is the file or directory path you wish to destroy. unix.fcntl(fd:int, unix.F_GETFD) ├─→ flags:int └─→ nil, unix.Errno Returns file descriptor flags. The returned `flags` may include any of: - `unix.FD_CLOEXEC` if `fd` was opened with `unix.O_CLOEXEC`. Returns `EBADF` if `fd` isn't open. unix.fcntl(fd:int, unix.F_SETFD, flags:int) ├─→ true └─→ nil, unix.Errno Sets file descriptor flags. `flags` may include any of: - `unix.FD_CLOEXEC` to re-open `fd` with `unix.O_CLOEXEC`. Returns `EBADF` if `fd` isn't open. unix.fcntl(fd:int, unix.F_GETFL) ├─→ flags:int └─→ nil, unix.Errno Returns file descriptor status flags. `flags & unix.O_ACCMODE` includes one of: - `O_RDONLY` - `O_WRONLY` - `O_RDWR` Examples of values `flags & ~unix.O_ACCMODE` may include: - `O_NONBLOCK` - `O_APPEND` - `O_SYNC` - `O_ASYNC` - `O_NOATIME` on Linux - `O_RANDOM` on Windows - `O_SEQUENTIAL` on Windows - `O_DIRECT` on Linux/FreeBSD/NetBSD/Windows Examples of values `flags & ~unix.O_ACCMODE` won't include: - `O_CREAT` - `O_TRUNC` - `O_EXCL` - `O_NOCTTY` Returns `EBADF` if `fd` isn't open. unix.fcntl(fd:int, unix.F_SETFL, flags:int) ├─→ true └─→ nil, unix.Errno Changes file descriptor status flags. Examples of values `flags` may include: - `O_NONBLOCK` - `O_APPEND` - `O_SYNC` - `O_ASYNC` - `O_NOATIME` on Linux - `O_RANDOM` on Windows - `O_SEQUENTIAL` on Windows - `O_DIRECT` on Linux/FreeBSD/NetBSD/Windows These values should be ignored: - `O_RDONLY`, `O_WRONLY`, `O_RDWR` - `O_CREAT`, `O_TRUNC`, `O_EXCL` - `O_NOCTTY` Returns `EBADF` if `fd` isn't open. unix.fcntl(fd:int, unix.F_SETLK[, type[, start[, len[, whence]]]]) unix.fcntl(fd:int, unix.F_SETLKW[, type[, start[, len[, whence]]]]) ├─→ true └─→ nil, unix.Errno Acquires lock on file interval. POSIX Advisory Locks allow multiple processes to leave voluntary hints to each other about which portions of a file they're using. The command may be: - `F_SETLK` to acquire lock if possible - `F_SETLKW` to wait for lock if necessary `fd` is file descriptor of open() file. `type` may be one of: - `F_RDLCK` for read lock (default) - `F_WRLCK` for read/write lock - `F_UNLCK` to unlock `start` is 0-indexed byte offset into file. The default is zero. `len` is byte length of interval. Zero is the default and it means until the end of the file. `whence` may be one of: - `SEEK_SET` start from beginning (default) - `SEEK_CUR` start from current position - `SEEK_END` start from end Returns `EAGAIN` if lock couldn't be acquired. POSIX says this theoretically could also be `EACCES` but we haven't seen this behavior on any of our supported platforms. Returns `EBADF` if `fd` wasn't open. unix.fcntl(fd:int, unix.F_GETLK[, type[, start[, len[, whence]]]]) ├─→ unix.F_UNLCK ├─→ type, start, len, whence, pid └─→ nil, unix.Errno Acquires information about POSIX advisory lock on file. This function accepts the same parameters as fcntl(F_SETLK) and tells you if the lock acquisition would be successful for a given range of bytes. If locking would have succeeded, then F_UNLCK is returned. If the lock would not have succeeded, then information about a conflicting lock is returned. Returned `type` may be `F_RDLCK` or `F_WRLCK`. Returned `pid` is the process id of the current lock owner. This function is currently not supported on Windows. Returns `EBADF` if `fd` wasn't open. unix.getsid(pid:int) ├─→ sid:int └─→ nil, unix.Errno Gets session id. unix.getpgrp() ├─→ pgid:int └─→ nil, unix.Errno Gets process group id. unix.setpgrp() ├─→ pgid:int └─→ nil, unix.Errno Sets process group id. This is the same as `setpgid(0,0)`. unix.setpgid(pid:int, pgid:int) ├─→ true └─→ nil, unix.Errno Sets process group id the modern way. unix.getpgid(pid:int) ├─→ pgid:int └─→ nil, unix.Errno Gets process group id the modern way. unix.setsid() ├─→ sid:int └─→ nil, unix.Errno Sets session id. This function can be used to create daemons. Fails with `ENOSYS` on Windows NT. unix.getuid() └─→ uid:int Gets real user id. On Windows this system call is polyfilled by running GetUserNameW() through Knuth's multiplicative hash. This function does not fail. unix.getgid() └─→ gid:int Sets real group id. On Windows this system call is polyfilled as getuid(). This function does not fail. unix.geteuid() └─→ uid:int Gets effective user id. For example, if your redbean is a setuid binary, then getuid() will return the uid of the user running the program, and geteuid() shall return zero which means root, assuming that's the file owning user. On Windows this system call is polyfilled as getuid(). This function does not fail. unix.getegid() └─→ gid:int Gets effective group id. On Windows this system call is polyfilled as getuid(). This function does not fail. unix.chroot(path:str) ├─→ true └─→ nil, unix.Errno Changes root directory. Returns `ENOSYS` on Windows NT. unix.setuid(uid:int) ├─→ true └─→ nil, unix.Errno Sets user id. One use case for this function is dropping root privileges. Should you ever choose to run redbean as root and decide not to use the `-G` and `-U` flags, you can replicate that behavior in the Lua processes you spawn as follows: ok, err = unix.setgid(1000) -- check your /etc/groups if not ok then Log(kLogFatal, tostring(err)) end ok, err = unix.setuid(1000) -- check your /etc/passwd if not ok then Log(kLogFatal, tostring(err)) end If your goal is to relinquish privileges because redbean is a setuid binary, then things are more straightforward: ok, err = unix.setgid(unix.getgid()) if not ok then Log(kLogFatal, tostring(err)) end ok, err = unix.setuid(unix.getuid()) if not ok then Log(kLogFatal, tostring(err)) end See also the setresuid() function and be sure to refer to your local system manual about the subtleties of changing user id in a way that isn't restorable. Returns `ENOSYS` on Windows NT if `uid` isn't `getuid()`. unix.setfsuid(uid:int) ├─→ true └─→ nil, unix.Errno Sets user id for file system ops. unix.setgid(gid:int) ├─→ true └─→ nil, unix.Errno Sets group id. Returns `ENOSYS` on Windows NT if `gid` isn't `getgid()`. unix.setresuid(real:int, effective:int, saved:int) ├─→ true └─→ nil, unix.Errno Sets real, effective, and saved user ids. If any of the above parameters are -1, then it's a no-op. Returns `ENOSYS` on Windows NT. Returns `ENOSYS` on Macintosh and NetBSD if `saved` isn't -1. unix.setresgid(real:int, effective:int, saved:int) ├─→ true └─→ nil, unix.Errno Sets real, effective, and saved group ids. If any of the above parameters are -1, then it's a no-op. Returns `ENOSYS` on Windows NT. Returns `ENOSYS` on Macintosh and NetBSD if `saved` isn't -1. unix.umask(newmask:int) └─→ oldmask:int Sets file permission mask and returns the old one. This is used to remove bits from the `mode` parameter of functions like open() and mkdir(). The masks typically used are 027 and 022. Those masks ensure that, even if a file is created with 0666 bits, it'll be turned into 0640 or 0644 so that users other than the owner can't modify it. To read the mask without changing it, try doing this: mask = unix.umask(027) unix.umask(mask) On Windows NT this is a no-op and `mask` is returned. This function does not fail. unix.syslog(priority:int, msg:str) Generates a log message, which will be distributed by syslogd. `priority` is a bitmask containing the facility value and the level value. If no facility value is ORed into priority, then the default value set by openlog() is used. If set to NULL, the program name is used. Level is one of `LOG_EMERG`, `LOG_ALERT`, `LOG_CRIT`, `LOG_ERR`, `LOG_WARNING`, `LOG_NOTICE`, `LOG_INFO`, `LOG_DEBUG`. This function currently works on Linux, Windows, and NetBSD. On WIN32 it uses the ReportEvent() facility. unix.clock_gettime([clock:int]) ├─→ seconds:int, nanos:int └─→ nil, unix.Errno Returns nanosecond precision timestamp from system, e.g. >: unix.clock_gettime() 1651137352 774458779 >: Benchmark(unix.clock_gettime) 126 393 571 1 `clock` can be any one of of: - `CLOCK_REALTIME`: universally supported - `CLOCK_REALTIME_FAST`: ditto but faster on freebsd - `CLOCK_REALTIME_PRECISE`: ditto but better on freebsd - `CLOCK_REALTIME_COARSE`: : like `CLOCK_REALTIME_FAST` but needs Linux 2.6.32+ - `CLOCK_MONOTONIC`: universally supported - `CLOCK_MONOTONIC_FAST`: ditto but faster on freebsd - `CLOCK_MONOTONIC_PRECISE`: ditto but better on freebsd - `CLOCK_MONOTONIC_COARSE`: : like `CLOCK_MONOTONIC_FAST` but needs Linux 2.6.32+ - `CLOCK_MONOTONIC_RAW`: is actually monotonic but needs Linux 2.6.28+ - `CLOCK_PROCESS_CPUTIME_ID`: linux and bsd - `CLOCK_THREAD_CPUTIME_ID`: linux and bsd - `CLOCK_MONOTONIC_COARSE`: linux, freebsd - `CLOCK_PROF`: linux and netbsd - `CLOCK_BOOTTIME`: linux and openbsd - `CLOCK_REALTIME_ALARM`: linux-only - `CLOCK_BOOTTIME_ALARM`: linux-only - `CLOCK_TAI`: linux-only Returns `EINVAL` if clock isn't supported on platform. This function only fails if `clock` is invalid. This function goes fastest on Linux and Windows. unix.nanosleep(seconds:int[, nanos:int]) ├─→ remseconds:int, remnanos:int └─→ nil, unix.Errno Sleeps with nanosecond precision. Returns `EINTR` if a signal was received while waiting. unix.sync() unix.fsync(fd:int) ├─→ true └─→ nil, unix.Errno unix.fdatasync(fd:int) ├─→ true └─→ nil, unix.Errno These functions are used to make programs slower by asking the operating system to flush data to the physical medium. unix.lseek(fd:int, offset:int[, whence:int]) ├─→ newposbytes:int └─→ nil, unix.Errno Seeks to file position. `whence` can be one of: - `SEEK_SET`: Sets the file position to `offset` [default] - `SEEK_CUR`: Sets the file position to `position + offset` - `SEEK_END`: Sets the file position to `filesize + offset` Returns the new position relative to the start of the file. unix.truncate(path:str[, length:int]) ├─→ true └─→ nil, unix.Errno Reduces or extends underlying physical medium of file. If file was originally larger, content >length is lost. `length` defaults to zero. unix.ftruncate(fd:int[, length:int]) ├─→ true └─→ nil, unix.Errno Reduces or extends underlying physical medium of open file. If file was originally larger, content >length is lost. `length` defaults to zero. unix.socket([family:int[, type:int[, protocol:int]]]) ├─→ fd:int └─→ nil, unix.Errno `family` defaults to `AF_INET` and can be: - `AF_INET`: Creates Internet Protocol Version 4 (IPv4) socket. - `AF_UNIX`: Creates local UNIX domain socket. On the New Technology this requires Windows 10 and only works with `SOCK_STREAM`. `type` defaults to `SOCK_STREAM` and can be: - `SOCK_STREAM` - `SOCK_DGRAM` - `SOCK_RAW` - `SOCK_RDM` - `SOCK_SEQPACKET` You may bitwise OR any of the following into `type`: - `SOCK_CLOEXEC` - `SOCK_NONBLOCK` `protocol` may be any of: - `0` to let kernel choose [default] - `IPPROTO_TCP` - `IPPROTO_UDP` - `IPPROTO_RAW` - `IPPROTO_IP` - `IPPROTO_ICMP` unix.socketpair([family:int[, type:int[, protocol:int]]]) ├─→ fd1:int, fd2:int └─→ nil, unix.Errno Creates bidirectional pipe. `family` defaults to `AF_UNIX`. `type` defaults to `SOCK_STREAM` and can be: - `SOCK_STREAM` - `SOCK_DGRAM` - `SOCK_SEQPACKET` You may bitwise OR any of the following into `type`: - `SOCK_CLOEXEC` - `SOCK_NONBLOCK` `protocol` defaults to `0`. unix.bind(fd:int[, ip:uint32, port:uint16]) unix.bind(fd:int[, unixpath:str]) ├─→ true └─→ nil, unix.Errno Binds socket. `ip` and `port` are in host endian order. For example, if you wanted to listen on `1.2.3.4:31337` you could do any of these unix.bind(sock, 0x01020304, 31337) unix.bind(sock, ParseIp('1.2.3.4'), 31337) unix.bind(sock, 1 << 24 | 0 << 16 | 0 << 8 | 1, 31337) `ip` and `port` both default to zero. The meaning of bind(0, 0) is to listen on all interfaces with a kernel-assigned ephemeral port number, that can be retrieved and used as follows: sock = assert(unix.socket()) -- create ipv4 tcp socket assert(unix.bind(sock)) -- all interfaces ephemeral port ip, port = assert(unix.getsockname(sock)) print("listening on ip", FormatIp(ip), "port", port) assert(unix.listen(sock)) while true do client, clientip, clientport = assert(unix.accept(sock)) print("got client ip", FormatIp(clientip), "port", clientport) unix.close(client) end Further note that calling `unix.bind(sock)` is equivalent to not calling bind() at all, since the above behavior is the default. unix.siocgifconf() ├─→ {{name:str,ip:uint32,netmask:uint32}, ...} └─→ nil, unix.Errno Returns list of network adapter addresses. unix.getsockopt(fd:int, level:int, optname:int) → ... unix.setsockopt(fd:int, level:int, optname:int, ...) → ok:bool, unix.Errno Tunes networking parameters. `level` and `optname` may be one of the following pairs. The ellipses type signature above changes depending on which options are used. `optname` is the option feature magic number. The constants for these will be set to `0` if the option isn't supported on the host platform. Raises `ENOPROTOOPT` if your `level` / `optname` combination isn't valid, recognized, or supported on the host platform. Raises `ENOTSOCK` if `fd` is valid but isn't a socket. Raises `EBADF` if `fd` isn't valid. unix.getsockopt(fd:int, level:int, optname:int) ├─→ value:int └─→ nil, unix.Errno unix.setsockopt(fd:int, level:int, optname:int, value:bool) ├─→ true └─→ nil, unix.Errno - `SOL_SOCKET`, `SO_TYPE` - `SOL_SOCKET`, `SO_DEBUG` - `SOL_SOCKET`, `SO_ACCEPTCONN` - `SOL_SOCKET`, `SO_BROADCAST` - `SOL_SOCKET`, `SO_REUSEADDR` - `SOL_SOCKET`, `SO_REUSEPORT` - `SOL_SOCKET`, `SO_KEEPALIVE` - `SOL_SOCKET`, `SO_DONTROUTE` - `SOL_TCP`, `TCP_NODELAY` - `SOL_TCP`, `TCP_CORK` - `SOL_TCP`, `TCP_QUICKACK` - `SOL_TCP`, `TCP_FASTOPEN_CONNECT` - `SOL_TCP`, `TCP_DEFER_ACCEPT` - `SOL_IP`, `IP_HDRINCL` unix.getsockopt(fd:int, level:int, optname:int) ├─→ value:int └─→ nil, unix.Errno unix.setsockopt(fd:int, level:int, optname:int, value:int) ├─→ true └─→ nil, unix.Errno - `SOL_SOCKET`, `SO_SNDBUF` - `SOL_SOCKET`, `SO_RCVBUF` - `SOL_SOCKET`, `SO_RCVLOWAT` - `SOL_SOCKET`, `SO_SNDLOWAT` - `SOL_TCP`, `TCP_KEEPIDLE` - `SOL_TCP`, `TCP_KEEPINTVL` - `SOL_TCP`, `TCP_FASTOPEN` - `SOL_TCP`, `TCP_KEEPCNT` - `SOL_TCP`, `TCP_MAXSEG` - `SOL_TCP`, `TCP_SYNCNT` - `SOL_TCP`, `TCP_NOTSENT_LOWAT` - `SOL_TCP`, `TCP_WINDOW_CLAMP` - `SOL_IP`, `IP_TOS` - `SOL_IP`, `IP_MTU` - `SOL_IP`, `IP_TTL` unix.getsockopt(fd:int, level:int, optname:int) ├─→ secs:int, nsecs:int └─→ nil, unix.Errno unix.setsockopt(fd:int, level:int, optname:int, secs:int[, nanos:int]) ├─→ true └─→ nil, unix.Errno - `SOL_SOCKET`, `SO_RCVTIMEO`: If this option is specified then your stream socket will have a read() / recv() timeout. If the specified interval elapses without receiving data, then EAGAIN shall be returned by read. If this option is used on listening sockets, it'll be inherited by accepted sockets. Your redbean already does this for GetClientFd() based on the `-t` flag. - `SOL_SOCKET`, `SO_SNDTIMEO`: This is the same as `SO_RCVTIMEO` but it applies to the write() / send() functions. unix.getsockopt(fd:int, unix.SOL_SOCKET, unix.SO_LINGER) ├─→ seconds:int, enabled:bool └─→ nil, unix.Errno unix.setsockopt(fd:int, unix.SOL_SOCKET, unix.SO_LINGER, secs:int, enabled:bool) ├─→ true └─→ nil, unix.Errno This `SO_LINGER` parameter can be used to make close() a blocking call. Normally when the kernel returns immediately when it receives close(). Sometimes it's desirable to have extra assurance on errors happened, even if it comes at the cost of performance. unix.setsockopt(serverfd:int, unix.SOL_TCP, unix.TCP_SAVE_SYN, enabled:int) ├─→ true └─→ nil, unix.Errno unix.getsockopt(clientfd:int, unix.SOL_TCP, unix.TCP_SAVED_SYN) ├─→ syn_packet_bytes:str └─→ nil, unix.Errno This `TCP_SAVED_SYN` option may be used to retrieve the bytes of the TCP SYN packet that the client sent when the connection for `fd` was opened. In order for this to work, `TCP_SAVE_SYN` must have been set earlier on the listening socket. This is Linux-only. You can use the `OnServerListen` hook to enable SYN saving in your Redbean. When the `TCP_SAVE_SYN` option isn't used, this may return empty string. unix.poll({[fd:int]=events:int, ...}[, timeoutms:int[, mask:unix.Sigset]]) ├─→ {[fd:int]=revents:int, ...} └─→ nil, unix.Errno Checks for events on a set of file descriptors. The table of file descriptors to poll uses sparse integer keys. Any pairs with non-integer keys will be ignored. Pairs with negative keys are ignored by poll(). The returned table will be a subset of the supplied file descriptors. `events` and `revents` may be any combination (using bitwise OR) of: - `POLLIN` (events, revents): There is data to read. - `POLLOUT` (events, revents): Writing is now possible, although may still block if available space in a socket or pipe is exceeded (unless `O_NONBLOCK` is set). - `POLLPRI` (events, revents): There is some exceptional condition (for example, out-of-band data on a TCP socket). - `POLLRDHUP` (events, revents): Stream socket peer closed connection, or shut down writing half of connection. - `POLLERR` (revents): Some error condition. - `POLLHUP` (revents): Hang up. When reading from a channel such as a pipe or a stream socket, this event merely indicates that the peer closed its end of the channel. - `POLLNVAL` (revents): Invalid request. `timeoutms` is the number of milliseconds to block. The default is -1 which means block indefinitely until there's an event or an interrupt. If the timeout elapses without any such events, an empty table is returned. A timeout of zero means non-blocking. `mask` serves the purpose of enabling poll to listen for both file descriptor events and signals. It's equivalent to saying: oldmask = unix.sigprocmask(unix.SIG_SETMASK, mask); unix.poll(fds, timeout); unix.sigprocmask(unix.SIG_SETMASK, oldmask); Except it'll happen atomically on supported platforms. The only exceptions are MacOS and NetBSD where this behavior is simulated by the polyfill. Atomicity is helpful for unit testing signal behavior. `EINTR` is returned if the kernel decided to deliver a signal to a signal handler instead during your call. This is a @norestart system call that always returns `EINTR` even if `SA_RESTART` is in play. unix.gethostname() ├─→ host:str └─→ nil, unix.Errno Returns hostname of system. unix.listen(fd:int[, backlog:int]) ├─→ true └─→ nil, unix.Errno Begins listening for incoming connections on a socket. unix.accept(serverfd:int[, flags:int]) ├─→ clientfd:int, ip:uint32, port:uint16 ├─→ clientfd:int, unixpath:str └─→ nil, unix.Errno Accepts new client socket descriptor for a listening tcp socket. `flags` may have any combination (using bitwise OR) of: - `SOCK_CLOEXEC` - `SOCK_NONBLOCK` unix.connect(fd:int, ip:uint32, port:uint16) unix.connect(fd:int, unixpath:str) ├─→ true └─→ nil, unix.Errno Connects a TCP socket to a remote host. With TCP this is a blocking operation. For a UDP socket it simply remembers the intended address so that send() or write() may be used rather than sendto(). unix.getsockname(fd:int) ├─→ ip:uint32, port:uint16 ├─→ unixpath:str └─→ nil, unix.Errno Retrieves the local address of a socket. unix.getpeername(fd:int) ├─→ ip:uint32, port:uint16 ├─→ unixpath:str └─→ nil, unix.Errno Retrieves the remote address of a socket. This operation will either fail on `AF_UNIX` sockets or return an empty string. unix.recv(fd:int[, bufsiz:int[, flags:int]]) ├─→ data:str └─→ nil, unix.Errno `flags` may have any combination (using bitwise OR) of: - `MSG_WAITALL` - `MSG_DONTROUTE` - `MSG_PEEK` - `MSG_OOB` unix.recvfrom(fd:int[, bufsiz:int[, flags:int]]) ├─→ data:str, ip:uint32, port:uint16 ├─→ data:str, unixpath:str └─→ nil, unix.Errno `flags` may have any combination (using bitwise OR) of: - `MSG_WAITALL` - `MSG_DONTROUTE` - `MSG_PEEK` - `MSG_OOB` unix.send(fd:int, data:str[, flags:int]) ├─→ sent:int └─→ nil, unix.Errno This is the same as `write` except it has a `flags` argument that's intended for sockets. `flags` may have any combination (using bitwise OR) of: - `MSG_NOSIGNAL`: Don't SIGPIPE on EOF - `MSG_OOB`: Send stream data through out of bound channel - `MSG_DONTROUTE`: Don't go through gateway (for diagnostics) - `MSG_MORE`: Manual corking to belay nodelay (0 on non-Linux) unix.sendto(fd:int, data:str, ip:uint32, port:uint16[, flags:int]) unix.sendto(fd:int, data:str, unixpath:str[, flags:int]) ├─→ sent:int └─→ nil, unix.Errno This is useful for sending messages over UDP sockets to specific addresses. `flags` may have any combination (using bitwise OR) of: - `MSG_OOB` - `MSG_DONTROUTE` - `MSG_NOSIGNAL` unix.shutdown(fd:int, how:int) ├─→ true └─→ nil, unix.Errno Partially closes socket. `how` is set to one of: - `SHUT_RD`: sends a tcp half close for reading - `SHUT_WR`: sends a tcp half close for writing - `SHUT_RDWR` This system call currently has issues on Macintosh, so portable code should log rather than assert failures reported by shutdown(). unix.sigprocmask(how:int, newmask:unix.Sigset) ├─→ oldmask:unix.Sigset └─→ nil, unix.Errno Manipulates bitset of signals blocked by process. `how` can be one of: - `SIG_BLOCK`: applies `mask` to set of blocked signals using bitwise OR - `SIG_UNBLOCK`: removes bits in `mask` from set of blocked signals - `SIG_SETMASK`: replaces process signal mask with `mask` `mask` is a unix.Sigset() object (see section below). For example, to temporarily block `SIGTERM` and `SIGINT` so critical work won't be interrupted, sigprocmask() can be used as follows: newmask = unix.Sigset(unix.SIGTERM) oldmask = assert(unix.sigprocmask(unix.SIG_BLOCK, newmask)) -- do something... assert(unix.sigprocmask(unix.SIG_SETMASK, oldmask)) unix.sigaction(sig:int[, handler:func|int[, flags:int[, mask:unix.Sigset]]]) ├─→ oldhandler:func|int, flags:int, mask:unix.Sigset └─→ nil, unix.Errno `sig` can be one of: - `unix.SIGINT` - `unix.SIGQUIT` - `unix.SIGTERM` - etc. `handler` can be: - Lua function - `unix.SIG_IGN` - `unix.SIG_DFL` `flags` can have: - `unix.SA_RESTART`: Enables BSD signal handling semantics. Normally i/o entrypoints check for pending signals to deliver. If one gets delivered during an i/o call, the normal behavior is to cancel the i/o operation and return -1 with `EINTR` in errno. If you use the `SA_RESTART` flag then that behavior changes, so that any function that's been annotated with @restartable will not return `EINTR` and will instead resume the i/o operation. This makes coding easier but it can be an anti-pattern if not used carefully, since poor usage can easily result in latency issues. It also requires one to do more work in signal handlers, so special care needs to be given to which C library functions are @asyncsignalsafe. - `unix.SA_RESETHAND`: Causes signal handler to be single-shot. This means that, upon entry of delivery to a signal handler, it's reset to the `SIG_DFL` handler automatically. You may use the alias `SA_ONESHOT` for this flag, which means the same thing. - `unix.SA_NODEFER`: Disables the reentrancy safety check on your signal handler. Normally that's a good thing, since for instance if your `SIGSEGV` signal handler happens to segfault, you're going to want your process to just crash rather than looping endlessly. But in some cases it's desirable to use `SA_NODEFER` instead, such as at times when you wish to `longjmp()` out of your signal handler and back into your program. This is only safe to do across platforms for non-crashing signals such as `SIGCHLD` and `SIGINT`. Crash handlers should use Xed instead to recover execution, because on Windows a `SIGSEGV` or `SIGTRAP` crash handler might happen on a separate stack and/or a separate thread. You may use the alias `SA_NOMASK` for this flag, which means the same thing. - `unix.SA_NOCLDWAIT`: Changes `SIGCHLD` so the zombie is gone and you can't call wait() anymore; similar but may still deliver the SIGCHLD. - `unix.SA_NOCLDSTOP`: Lets you set `SIGCHLD` handler that's only notified on exit/termination and not notified on `SIGSTOP`, `SIGTSTP`, `SIGTTIN`, `SIGTTOU`, or `SIGCONT`. Example: function OnSigUsr1(sig) gotsigusr1 = true end gotsigusr1 = false oldmask = assert(unix.sigprocmask(unix.SIG_BLOCK, unix.Sigset(unix.SIGUSR1))) assert(unix.sigaction(unix.SIGUSR1, OnSigUsr1)) assert(unix.raise(unix.SIGUSR1)) assert(not gotsigusr1) ok, err = unix.sigsuspend(oldmask) assert(not ok) assert(err:errno() == unix.EINTR) assert(gotsigusr1) assert(unix.sigprocmask(unix.SIG_SETMASK, oldmask)) It's a good idea to not do too much work in a signal handler. unix.sigpending() ├─→ mask:unix.Sigset └─→ nil, unix.Errno Returns the set of signals that are pending for delivery. unix.sigsuspend([mask:unix.Sigset]) └─→ nil, unix.Errno Waits for signal to be delivered. The signal mask is temporarily replaced with `mask` during this system call. `mask` specifies which signals should be blocked. unix.setitimer(which[, intervalsec, intns, valuesec, valuens]) ├─→ intervalsec:int, intervalns:int, valuesec:int, valuens:int └─→ nil, unix.Errno Causes `SIGALRM` signals to be generated at some point(s) in the future. The `which` parameter should be `ITIMER_REAL`. Here's an example of how to create a 400 ms interval timer: ticks = 0 assert(unix.sigaction(unix.SIGALRM, function(sig) print('tick no. %d' % {ticks}) ticks = ticks + 1 end)) assert(unix.setitimer(unix.ITIMER_REAL, 0, 400e6, 0, 400e6)) while true do unix.sigsuspend() end Here's how you'd do a single-shot timeout in 1 second: unix.sigaction(unix.SIGALRM, MyOnSigAlrm, unix.SA_RESETHAND) unix.setitimer(unix.ITIMER_REAL, 0, 0, 1, 0) `intns` needs to be on the interval `[0,1000000000)` `valuens` needs to be on the interval `[0,1000000000)` unix.strsignal(sig:int) → str Turns platform-specific `sig` code into its symbolic name. For example: >: unix.strsignal(9) "SIGKILL" >: unix.strsignal(unix.SIGKILL) "SIGKILL" Please note that signal numbers are normally different across supported platforms, and the constants should be preferred. unix.setrlimit(resource:int, soft:int[, hard:int]) ├─→ true └─→ nil, unix.Errno Changes resource limit. `resource` may be one of: - `RLIMIT_AS` limits the size of the virtual address space. This will work on all platforms. It's emulated on XNU and Windows which means it won't propagate across execve() currently. - `RLIMIT_CPU` causes `SIGXCPU` to be sent to the process when the soft limit on CPU time is exceeded, and the process is destroyed when the hard limit is exceeded. It works everywhere but Windows where it should be possible to poll getrusage() with setitimer(). - `RLIMIT_FSIZE` causes `SIGXFSZ` to sent to the process when the soft limit on file size is exceeded and the process is destroyed when the hard limit is exceeded. It works everywhere but Windows. - `RLIMIT_NPROC` limits the number of simultaneous processes and it should work on all platforms except Windows. Please be advised it limits the process, with respect to the activities of the user id as a whole. - `RLIMIT_NOFILE` limits the number of open file descriptors and it should work on all platforms except Windows (TODO). If a limit isn't supported by the host platform, it'll be set to 127. On most platforms these limits are enforced by the kernel and as such are inherited by subprocesses. `hard` defaults to whatever was specified in `soft`. unix.getrlimit(resource:int) ├─→ soft:int, hard:int └─→ nil, unix.Errno Returns information about resource limits for current process. unix.getrusage([who:int]) ├─→ unix.Rusage └─→ nil, unix.Errno Returns information about resource usage for current process, e.g. >: unix.getrusage() {utime={0, 53644000}, maxrss=44896, minflt=545, oublock=24, nvcsw=9} `who` defaults to `RUSAGE_SELF` and can be any of: - `RUSAGE_SELF`: current process - `RUSAGE_THREAD`: current thread - `RUSAGE_CHILDREN`: not supported on Windows NT - `RUSAGE_BOTH`: not supported on non-Linux See the unix.Rusage section below for details on returned fields. unix.pledge([promises:str[, execpromises:str[, mode:int]]]) ├─→ true └─→ nil, unix.Errno Restrict system operations. This can be used to sandbox your redbean workers. It allows finer customization compared to the `-S` flag. Pledging causes most system calls to become unavailable. If a forbidden system call is used, then the process will be killed. In that case, on OpenBSD, your system log will explain which promise you need. On Linux, we report the promise to stderr, with one exception: reporting is currently not possible if you pledge exec. Using pledge is irreversible. On Linux it causes PR_SET_NO_NEW_PRIVS to be set on your process. By default exit and exit_group are always allowed. This is useful for processes that perform pure computation and interface with the parent via shared memory. Once pledge is in effect, the chmod functions (if allowed) will not permit the sticky/setuid/setgid bits to change. Linux will EPERM here and OpenBSD should ignore those three bits rather than crashing. User and group IDs also can't be changed once pledge is in effect. OpenBSD should ignore the chown functions without crashing. Linux will just EPERM. `promises` is a string that may include any of the following groups delimited by spaces. This list has been curated to focus on the system calls for which this module provides wrappers. See the Cosmopolitan Libc pledge() documentation for a comprehensive and authoritative list of raw system calls. Having the raw system call list may be useful if you're executing foreign programs. stdio Allows read, write, send, recv, recvfrom, close, clock_getres, clock_gettime, dup, fchdir, fstat, fsync, fdatasync, ftruncate, getdents, getegid, getrandom, geteuid, getgid, getgroups, getitimer, getpgid, getpgrp, getpid, hgetppid, getresgid, getresuid, getrlimit, getsid, gettimeofday, getuid, lseek, madvise, brk, mmap/mprotect (PROT_EXEC isn't allowed), msync, munmap, gethostname, nanosleep, pipe, pipe2, poll, setitimer, shutdown, sigaction, sigsuspend, sigprocmask, socketpair, umask, wait4, getrusage, ioctl(FIONREAD), ioctl(FIONBIO), ioctl(FIOCLEX), ioctl(FIONCLEX), fcntl(F_GETFD), fcntl(F_SETFD), fcntl(F_GETFL), fcntl(F_SETFL), raise, kill(getpid()). rpath Allows chdir, getcwd, open, stat, fstat, access, readlink, chmod, chmod, fchmod. wpath Allows getcwd, open, stat, fstat, access, readlink, chmod, fchmod. cpath Allows rename, link, symlink, unlink, mkdir, rmdir. fattr Allows chmod, fchmod, utimensat, futimens. flock Allows flock, fcntl(F_GETLK), fcntl(F_SETLK), fcntl(F_SETLKW). tty Allows isatty, tiocgwinsz, tcgets, tcsets, tcsetsw, tcsetsf. inet Allows socket (AF_INET), listen, bind, connect, accept, getpeername, getsockname, setsockopt, getsockopt. unix Allows socket (AF_UNIX), listen, bind, connect, accept, getpeername, getsockname, setsockopt, getsockopt. dns Allows sendto, recvfrom, socket(AF_INET), connect. recvfd Allows recvmsg, recvmmsg. sendfd Allows sendmsg, sendmmsg. proc Allows fork, vfork, clone, kill, tgkill, getpriority, setpriority, setrlimit, setpgid, setsid. id Allows setuid, setreuid, setresuid, setgid, setregid, setresgid, setgroups, setrlimit, getpriority, setpriority. settime Allows settimeofday and clock_adjtime. chown Allows chown. unveil Allows unveil(). exec Allows execve. If the executable in question needs a loader, then you will need "rpath prot_exec" too. With APE, security is strongest when you assimilate your binaries beforehand, using the --assimilate flag, or the o//tool/build/assimilate.com program. On OpenBSD this is mandatory. prot_exec Allows mmap(PROT_EXEC) and mprotect(PROT_EXEC). This may be needed to launch non-static non-native executables, such as non-assimilated APE binaries, or programs that link dynamic shared objects, i.e. most Linux distro binaries. `execpromises` only matters if "exec" is specified in `promises`. In that case, this specifies the promises that'll apply once execve() happens. If this is NULL then the default is used, which is unrestricted. OpenBSD allows child processes to escape the sandbox (so a pledged OpenSSH server process can do things like spawn a root shell). Linux however requires monotonically decreasing privileges. This function will will perform some validation on Linux to make sure that `execpromises` is a subset of `promises`. Your libc wrapper for execve() will then apply its SECCOMP BPF filter later. Since Linux has to do this before calling sys_execve(), the executed process will be weakened to have execute permissions too. `mode` if specified should specify one penalty: - `unix.PLEDGE_PENALTY_KILL_THREAD` causes the violating thread to be killed. This is the default on Linux. It's effectively the same as killing the process, since redbean has no threads. The termination signal can't be caught and will be either `SIGSYS` or `SIGABRT`. Consider enabling stderr logging below so you'll know why your program failed. Otherwise check the system log. - `unix.PLEDGE_PENALTY_KILL_PROCESS` causes the process and all its threads to be killed. This is always the case on OpenBSD. - `unix.PLEDGE_PENALTY_RETURN_EPERM` causes system calls to just return an `EPERM` error instead of killing. This is a gentler solution that allows code to display a friendly warning. Please note this may lead to weird behaviors if the software being sandboxed is lazy about checking error results. `mode` may optionally bitwise or the following flags: - `unix.PLEDGE_STDERR_LOGGING` enables friendly error message logging letting you know which promises are needed whenever violations occur. Without this, violations will be logged to `dmesg` on Linux if the penalty is to kill the process. You would then need to manually look up the system call number and then cross reference it with the cosmopolitan libc pledge() documentation. You can also use `strace -ff` which is easier. This is ignored OpenBSD, which already has a good system log. Turning on stderr logging (which uses SECCOMP trapping) also means that the `unix.WTERMSIG()` on your killed processes will always be `unix.SIGABRT` on both Linux and OpenBSD. Otherwise, Linux prefers to raise `unix.SIGSYS`. unix.unveil(path:str, permissions:str) ├─→ true └─→ nil, unix.Errno Restricts filesystem operations, e.g. unix.unveil(".", "r"); -- current dir + children visible unix.unveil("/etc", "r"); -- make /etc readable too unix.unveil(nil, nil); -- commit and lock policy Unveiling restricts a thread's view of the filesystem to a set of allowed paths with specific privileges. Once you start using unveil(), the entire file system is considered hidden. You then specify, by repeatedly calling unveil(), which paths should become unhidden. When you're finished, you call `unveil(nil,nil)` which commits your policy, after which further use is forbidden, in the current thread, as well as any threads or processes it spawns. There are some differences between unveil() on Linux versus OpenBSD. 1. Build your policy and lock it in one go. On OpenBSD, policies take effect immediately and may evolve as you continue to call unveil() but only in a more restrictive direction. On Linux, nothing will happen until you call `unveil(nil,nil)` which commits and locks. 2. Try not to overlap directory trees. On OpenBSD, if directory trees overlap, then the most restrictive policy will be used for a given file. On Linux overlapping may result in a less restrictive policy and possibly even undefined behavior. 3. OpenBSD and Linux disagree on error codes. On OpenBSD, accessing paths outside of the allowed set raises ENOENT, and accessing ones with incorrect permissions raises EACCES. On Linux, both these cases raise EACCES. 4. Unlike OpenBSD, Linux does nothing to conceal the existence of paths. Even with an unveil() policy in place, it's still possible to access the metadata of all files using functions like stat() and open(O_PATH), provided you know the path. A sandboxed process can always, for example, determine how many bytes of data are in /etc/passwd, even if the file isn't readable. But it's still not possible to use opendir() and go fishing for paths which weren't previously known. This system call is supported natively on OpenBSD and polyfilled on Linux using the Landlock LSM[1]. `path` is the file or directory to unveil `permissions` is a string consisting of zero or more of the following characters: - 'r' makes `path` available for read-only path operations, corresponding to the pledge promise "rpath". - `w` makes `path` available for write operations, corresponding to the pledge promise "wpath". - `x` makes `path` available for execute operations, corresponding to the pledge promises "exec" and "execnative". - `c` allows `path` to be created and removed, corresponding to the pledge promise "cpath". unix.gmtime(unixts:int) ├─→ year,mon,mday,hour,min,sec,gmtoffsec,wday,yday,dst:int,zone:str └─→ nil,unix.Errno Breaks down UNIX timestamp into Zulu Time numbers. - `mon` 1 ≤ mon ≤ 12 - `mday` 1 ≤ mday ≤ 31 - `hour` 0 ≤ hour ≤ 23 - `min` 0 ≤ min ≤ 59 - `sec` 0 ≤ sec ≤ 60 - `gmtoff` ±93600 seconds - `wday` 0 ≤ wday ≤ 6 - `yday` 0 ≤ yday ≤ 365 - `dst` 1 if daylight savings, 0 if not, -1 if not unknown unix.localtime(unixts:int) ├─→ year,mon,mday,hour,min,sec,gmtoffsec,wday,yday,dst:int,zone:str └─→ nil,unix.Errno Breaks down UNIX timestamp into local time numbers, e.g. >: unix.localtime(unix.clock_gettime()) 2022 4 28 2 14 22 -25200 4 117 1 "PDT" This follows the same API as gmtime() which has further details. Your redbean ships with a subset of the time zone database. - `/zip/usr/share/zoneinfo/Honolulu` Z-10 - `/zip/usr/share/zoneinfo/Anchorage` Z -9 - `/zip/usr/share/zoneinfo/GST` Z -8 - `/zip/usr/share/zoneinfo/Boulder` Z -6 - `/zip/usr/share/zoneinfo/Chicago` Z -5 - `/zip/usr/share/zoneinfo/New_York` Z -4 - `/zip/usr/share/zoneinfo/UTC` Z +0 - `/zip/usr/share/zoneinfo/GMT` Z +0 - `/zip/usr/share/zoneinfo/London` Z +1 - `/zip/usr/share/zoneinfo/Berlin` Z +2 - `/zip/usr/share/zoneinfo/Israel` Z +3 - `/zip/usr/share/zoneinfo/India` Z +5 - `/zip/usr/share/zoneinfo/Beijing` Z +8 - `/zip/usr/share/zoneinfo/Japan` Z +9 - `/zip/usr/share/zoneinfo/Sydney` Z+10 You can control which timezone is used using the `TZ` environment variable. If your time zone isn't included in the above list, you can simply copy it inside your redbean. The same is also the case for future updates to the database, which can be swapped out when needed, without having to recompile. unix.stat(path:str[, flags:int[, dirfd:int]]) ├─→ unix.Stat └─→ nil, unix.Errno Gets information about file or directory. `flags` may have any of: - `AT_SYMLINK_NOFOLLOW`: do not follow symbolic links. `dirfd` defaults to to `unix.AT_FDCWD` and may optionally be set to a directory file descriptor to which `path` is relative. unix.fstat(fd:int) ├─→ unix.Stat └─→ nil, unix.Errno Gets information about opened file descriptor. A common use for fstat() is getting the size of a file. For example: fd = assert(unix.open("hello.txt", unix.O_RDONLY)) st = assert(unix.fstat(fd)) Log(kLogInfo, 'hello.txt is %d bytes in size' % {st:size()}) unix.close(fd) unix.statfs(path:str) ├─→ unix.Statfs └─→ nil, unix.Errno Gets information about filesystem. `path` is the path of a file or directory in the mounted filesystem. unix.fstatfs(fd:int) ├─→ unix.Statfs └─→ nil, unix.Errno Gets information about filesystem. `fd` is an open() file descriptor of a file or directory in the mounted filesystem. unix.opendir(path:str) ├─→ state:unix.Dir └─→ nil, unix.Errno Opens directory for listing its contents. For example, to print a simple directory listing: Write('
    \r\n') for name, kind, ino, off in assert(unix.opendir(dir)) do if name ~= '.' and name ~= '..' then Write('
  • %s\r\n' % {EscapeHtml(name)}) end end Write('
\r\n') unix.fdopendir(fd:int) ├─→ next:function, state:unix.Dir └─→ nil, unix.Errno Opens directory for listing its contents, via an fd. `fd` should be created by `open(path, O_RDONLY|O_DIRECTORY)`. The returned unix.Dir takes ownership of the file descriptor and will close it automatically when garbage collected. unix.isatty(fd:int) ├─→ true └─→ nil, unix.Errno Returns true if file descriptor is a teletypewriter. Otherwise nil with an Errno object holding one of the following values: - `ENOTTY` if `fd` is valid but not a teletypewriter - `EBADF` if `fd` isn't a valid file descriptor. - `EPERM` if pledge() is used without `tty` in lenient mode No other error numbers are possible. unix.tiocgwinsz(fd:int) ├─→ rows:int, cols:int └─→ nil, unix.Errno Returns cellular dimensions of pseudoteletypewriter display. unix.tmpfd() ├─→ fd:int └─→ nil, unix.Errno Returns file descriptor of open anonymous file. This creates a secure temporary file inside `$TMPDIR`. If it isn't defined, then `/tmp` is used on UNIX and GetTempPath() is used on the New Technology. This resolution of `$TMPDIR` happens once in a ctor, which is copied to the `kTmpDir` global. Once close() is called, the returned file is guaranteed to be deleted automatically. On UNIX the file is unlink()'d before this function returns. On the New Technology it happens upon close(). On the New Technology, temporary files created by this function should have better performance, because `kNtFileAttributeTemporary` asks the kernel to more aggressively cache and reduce i/o ops. unix.sched_yield() Relinquishes scheduled quantum. unix.mapshared(size:int) └─→ unix.Memory() Creates interprocess shared memory mapping. This function allocates special memory that'll be inherited across fork in a shared way. By default all memory in Redbean is "private" memory that's only viewable and editable to the process that owns it. When unix.fork() happens, memory is copied appropriately so that changes to memory made in the child process, don't clobber the memory at those same addresses in the parent process. If you don't want that to happen, and you want the memory to be shared similar to how it would be shared if you were using threads, then you can use this function to achieve just that. The memory object this function returns may be accessed using its methods, which support atomics and futexes. It's very low-level. For example, you can use it to implement scalable mutexes: mem = unix.mapshared(8000 * 8) LOCK = 0 -- pick an arbitrary word index for lock -- From Futexes Are Tricky Version 1.1 § Mutex, Take 3; -- Ulrich Drepper, Red Hat Incorporated, June 27, 2004. function Lock() local ok, old = mem:cmpxchg(LOCK, 0, 1) if not ok then if old == 1 then old = mem:xchg(LOCK, 2) end while old > 0 do mem:wait(LOCK, 2) old = mem:xchg(LOCK, 2) end end end function Unlock() old = mem:fetch_add(LOCK, -1) if old == 2 then mem:store(LOCK, 0) mem:wake(LOCK, 1) end end It's possible to accomplish the same thing as unix.mapshared() using files and unix.fcntl() advisory locks. However this goes significantly faster. For example, that's what SQLite does and we recommend using SQLite for IPC in redbean. But, if your app has thousands of forked processes fighting for a file lock you might need something lower level than file locks, to implement things like throttling. Shared memory is a good way to do that since there's nothing that's faster. The `size` parameter needs to be a multiple of 8. The returned memory is zero initialized. When allocating shared memory, you should try to get as much use out of it as possible, since the overhead of allocating a single shared mapping is 500 words of resident memory and 8000 words of virtual memory. It's because the Cosmopolitan Libc mmap() granularity is 2**16. This system call does not fail. An exception is instead thrown if sufficient memory isn't available. ──────────────────────────────────────────────────────────────────────────────── UNIX MEMORY OBJECT unix.Memory encapsulates memory that's shared across fork() and this module provides the fundamental synchronization primitives Redbean memory maps may be used in two ways: 1. as an array of bytes a.k.a. a string 2. as an array of words a.k.a. integers They're aliased, union, or overlapped views of the same memory. For example if you write a string to your memory region, you'll be able to read it back as an integer. Reads, writes, and word operations will throw an exception if a memory boundary error or overflow occurs. unix.Memory:read([offset:int[, bytes:int]]) └─→ str Reads bytes from memory region `offset` is the starting byte index from which memory is copied, which defaults to zero. If `bytes` is none or nil, then the nul-terminated string at `offset` is returned. You may specify `bytes` to safely read binary data. This operation happens atomically. Each shared mapping has a single lock which is used to synchronize reads and writes to that specific map. To make it scale, create additional maps. unix.Memory:write([offset:int,] data:str[, bytes:int]]) Writes bytes to memory region. `offset` is the starting byte index to which memory is copied, which defaults to zero. If `bytes` is none or nil, then an implicit nil-terminator will be included after your `data` so things like json can be easily serialized to shared memory. This operation happens atomically. Each shared mapping has a single lock which is used to synchronize reads and writes to that specific map. To make it scale, create additional maps. unix.Memory:load(word_index:int) └─→ int Loads word from memory region. This operation is atomic and has relaxed barrier semantics. unix.Memory:store(word_index:int, value:int) Stores word from memory region. This operation is atomic and has relaxed barrier semantics. unix.Memory:xchg(word_index:int, value:int) └─→ int Exchanges value. This sets word at `word_index` to `value` and returns the value previously held within that word. This operation is atomic and provides the same memory barrier semantics as the aligned x86 LOCK XCHG instruction. unix.Memory:cmpxchg(word_index:int, old:int, new:int) └─→ success:bool, old:int Compares and exchanges value. This inspects the word at `word_index` and if its value is the same as `old` then it'll be replaced by the value `new`, in which case true shall be returned alongside `old`. If a different value was held at word, then `false` shall be returned along with its value. This operation happens atomically and provides the same memory barrier semantics as the aligned x86 LOCK CMPXCHG instruction. unix.Memory:fetch_add(word_index:int, value:int) └─→ old:int Fetches then adds value. This method modifies the word at `word_index` to contain the sum of its value and the `value` parameter. This method then returns the value as it existed before the addition was performed. This operation is atomic and provides the same memory barrier semantics as the aligned x86 LOCK XADD instruction. unix.Memory:fetch_and(word_index:int, value:int) └─→ int Fetches and bitwise ands value. This operation happens atomically and provides the same memory barrier ordering semantics as its x86 implementation. unix.Memory:fetch_or(word_index:int, value:int) └─→ int Fetches and bitwise ors value. This operation happens atomically and provides the same memory barrier ordering semantics as its x86 implementation. unix.Memory:fetch_xor(word_index:int, value:int) └─→ int Fetches and bitwise xors value. This operation happens atomically and provides the same memory barrier ordering semantics as its x86 implementation. unix.Memory:wait(word_index:int, expect:int[, abs_deadline:int[, nanos:int]]) ├─→ 0 ├─→ nil, unix.Errno(unix.EINTR) ├─→ nil, unix.Errno(unix.EAGAIN) └─→ nil, unix.Errno(unix.ETIMEDOUT) Waits for word to have a different value. This method asks the kernel to suspend the process until either the absolute deadline expires or we're woken up by another process that calls unix.Memory:wake(). The `expect` parameter is the value you expect the word to have and this function will return if that's not the case. Please note this parameter doesn't imply the kernel will poll the value for you, and you still need to call wake() when you know the memory's changed. The default behavior is to wait until the heat death of the universe if necessary. You may alternatively specify an absolute deadline. If it's less than or equal to the value returned by clock_gettime, then this routine is non-blocking. Otherwise we'll block at most until the current time reaches the absolute deadline. Futexes are supported natively on Linux, FreeBSD, and OpenBSD. When this interface is used on other platforms this method will manually poll the memory location with exponential backoff. Doing this works well enough that we're passing the *NSYNC unit tests, but is not as low latency as having kernel supported futexes. `EINTR` if a signal is delivered while waiting on deadline. Callers should use futexes inside a loop that is able to cope with spurious wakeups. We don't actually guarantee the value at word has in fact changed when this returns. `EAGAIN` is raised if, upon entry, the word at `word_index` had a different value than what's specified at `expect`. `ETIMEDOUT` is raised when the absolute deadline expires. unix.Memory:wake(index:int[, count:int]) └─→ woken:int Wakes other processes waiting on word. This method may be used to signal or broadcast to waiters. The `count` specifies the number of processes that should be woken, which defaults to `INT_MAX`. The return value is the number of processes that were actually woken as a result of the system call. No failure conditions are defined. ──────────────────────────────────────────────────────────────────────────────── UNIX DIR OBJECT unix.Dir objects are created by opendir() or fdopendir(). The following methods are available: unix.Dir:close() ├─→ true └─→ nil, unix.Errno Closes directory stream object and associated its file descriptor. This is called automatically by the garbage collector. This may be called multiple times. unix.Dir:read() ├─→ name:str, kind:int, ino:int, off:int └─→ nil Reads entry from directory stream. Returns `nil` if there are no more entries. On error, `nil` will be returned and `errno` will be non-nil. `kind` can be any of: - `DT_REG`: file is a regular file - `DT_DIR`: file is a directory - `DT_BLK`: file is a block device - `DT_LNK`: file is a symbolic link - `DT_CHR`: file is a character device - `DT_FIFO`: file is a named pipe - `DT_SOCK`: file is a named socket - `DT_UNKNOWN` Note: This function also serves as the `__call` metamethod, so that unix.Dir objects may be used as a for loop iterator. unix.Dir:fd() ├─→ fd:int └─→ nil, unix.Errno Returns file descriptor of open directory object. Returns `EOPNOTSUPP` if using a `/zip/...` path. Returns `EOPNOTSUPP` if using Windows NT. unix.Dir:tell() ├─→ off:int └─→ nil, unix.Errno Returns current arbitrary offset into stream. unix.Dir:rewind() Resets stream back to beginning. ──────────────────────────────────────────────────────────────────────────────── UNIX RUSAGE OBJECT unix.Rusage objects are created by wait() or getrusage(). The following accessor methods are available. unix.Rusage:utime() └─→ seconds:int, nanos:int Returns amount of CPU consumed in userspace. It's always the case that `0 ≤ nanos < 1e9`. On Windows NT this is collected from GetProcessTimes(). unix.Rusage:stime() └─→ seconds:int, nanos:int Returns amount of CPU consumed in kernelspace. It's always the case that `0 ≤ 𝑥 < 1e9`. On Windows NT this is collected from GetProcessTimes(). unix.Rusage:maxrss() └─→ kilobytes:int Returns amount of physical memory used at peak consumption. On Windows NT this is collected from NtProcessMemoryCountersEx::PeakWorkingSetSize / 1024. unix.Rusage:idrss() └─→ integralkilobytes:int Returns integral private memory consumption w.r.t. scheduled ticks. If you chart memory usage over the lifetime of your process, then this would be the space filled in beneath the chart. The frequency of kernel scheduling is defined as unix.CLK_TCK. Each time a tick happens, the kernel samples your process's memory usage, by adding it to this value. You can derive the average consumption from this value by computing how many ticks are in `utime + stime`. Currently only available on FreeBSD and NetBSD. unix.Rusage:ixrss() └─→ integralkilobytes:int Returns integral shared memory consumption w.r.t. scheduled ticks. If you chart memory usage over the lifetime of your process, then this would be the space filled in beneath the chart. The frequency of kernel scheduling is defined as unix.CLK_TCK. Each time a tick happens, the kernel samples your process's memory usage, by adding it to this value. You can derive the average consumption from this value by computing how many ticks are in `utime + stime`. Currently only available on FreeBSD and NetBSD. unix.Rusage:isrss() └─→ integralkilobytes:int Returns integral stack memory consumption w.r.t. scheduled ticks. If you chart memory usage over the lifetime of your process, then this would be the space filled in beneath the chart. The frequency of kernel scheduling is defined as unix.CLK_TCK. Each time a tick happens, the kernel samples your process's memory usage, by adding it to this value. You can derive the average consumption from this value by computing how many ticks are in `utime + stime`. This is only applicable to redbean if its built with MODE=tiny, because redbean likes to allocate its own deterministic stack. Currently only available on FreeBSD and NetBSD. unix.Rusage:minflt() └─→ count:int Returns number of minor page faults. This number indicates how many times redbean was preempted by the kernel to memcpy() a 4096-byte page. This is one of the tradeoffs fork() entails. This number is usually tinier, when your binaries are tinier. Not available on Windows NT. unix.Rusage:majflt() └─→ count:int Returns number of major page faults. This number indicates how many times redbean was preempted by the kernel to perform i/o. For example, you might have used mmap() to load a large file into memory lazily. On Windows NT this is NtProcessMemoryCountersEx::PageFaultCount. unix.Rusage:nswap() └─→ count:int Returns number of swap operations. Operating systems like to reserve hard disk space to back their RAM guarantees, like using a gold standard for fiat currency. When your system is under heavy memory load, swap operations may happen while redbean is working. This number keeps track of them. Not available on Linux, Windows NT. unix.Rusage:inblock() └─→ count:int Returns number of times filesystem had to perform input. On Windows NT this is NtIoCounters::ReadOperationCount. unix.Rusage:oublock() └─→ count:int Returns number of times filesystem had to perform output. On Windows NT this is NtIoCounters::WriteOperationCount. unix.Rusage:msgsnd() └─→ count:int Returns count of ipc messages sent. Not available on Linux, Windows NT. unix.Rusage:msgrcv() └─→ count:int Returns count of ipc messages received. Not available on Linux, Windows NT. unix.Rusage:nsignals() └─→ count:int Returns number of signals received. Not available on Linux. unix.Rusage:nvcsw() └─→ count:int Returns number of voluntary context switches. This number is a good thing. It means your redbean finished its work quickly enough within a time slice that it was able to give back the remaining time to the system. unix.Rusage:nivcsw() └─→ count:int Returns number of non-consensual context switches. This number is a bad thing. It means your redbean was preempted by a higher priority process after failing to finish its work, within the allotted time slice. ──────────────────────────────────────────────────────────────────────────────── UNIX STAT OBJECT unix.Stat objects are created by stat() or fstat(). The following accessor methods are available. unix.Stat:size() └─→ bytes:int Size of file in bytes. unix.Stat:mode() └─→ mode:int Contains file type and permissions. For example, `0010644` is what you might see for a file and `0040755` is what you might see for a directory. To determine the file type: - `unix.S_ISREG(st:mode())` means regular file - `unix.S_ISDIR(st:mode())` means directory - `unix.S_ISLNK(st:mode())` means symbolic link - `unix.S_ISCHR(st:mode())` means character device - `unix.S_ISBLK(st:mode())` means block device - `unix.S_ISFIFO(st:mode())` means fifo or pipe - `unix.S_ISSOCK(st:mode())` means socket unix.Stat:uid() └─→ uid:int User ID of file owner. unix.Stat:gid() └─→ gid:int Group ID of file owner. unix.Stat:birthtim() └─→ unixts:int, nanos:int File birth time. This field should be accurate on Apple, Windows, and BSDs. On Linux this is the minimum of atim/mtim/ctim. On Windows NT nanos is only accurate to hectonanoseconds. Here's an example of how you might print a file timestamp: st = assert(unix.stat('/etc/passwd')) unixts, nanos = st:birthtim() year,mon,mday,hour,min,sec,gmtoffsec = unix.localtime(unixts) Write('%.4d-%.2d-%.2dT%.2d:%.2d:%.2d.%.9d%+.2d%.2d % { year, mon, mday, hour, min, sec, nanos, gmtoffsec / (60 * 60), math.abs(gmtoffsec) % 60}) unix.Stat:mtim() └─→ unixts:int, nanos:int Last modified time. unix.Stat:atim() └─→ unixts:int, nanos:int Last access time. Please note that file systems are sometimes mounted with `noatime` out of concern for i/o performance. Linux also provides `O_NOATIME` as an option for open(). On Windows NT this is the same as birth time. unix.Stat:ctim() └─→ unixts:int, nanos:int Complicated time. Means time file status was last changed on UNIX. On Windows NT this is the same as birth time. unix.Stat:blocks() └─→ count512:int Number of 512-byte blocks used by storage medium. This provides some indication of how much physical storage a file actually consumes. For example, for small file systems, your system might report this number as being 8, which means 4096 bytes. On Windows NT, if `O_COMPRESSED` is used for a file, then this number will reflect the size *after* compression. you can use: st = assert(unix.stat("moby.txt")) print('file size is %d bytes' % {st:size()}) print('file takes up %d bytes of space' % {st:blocks() * 512}) if GetHostOs() == 'WINDOWS' and st:flags() & 0x800 then print('thanks to file system compression') end To tell if compression is used on a file. unix.Stat:blksize() └─→ bytes:int Block size that underlying device uses. This field might be of assistance in computing optimal i/o sizes. Please note this field has no relationship to blocks, as the latter is fixed at a 512 byte size. unix.Stat:ino() └─→ inode:int Inode number. This can be used to detect some other process used rename() to swap out a file underneath you, so you can do a refresh. redbean does it during each main process heartbeat for its own use cases. On Windows NT this is set to NtByHandleFileInformation::FileIndex. unix.Stat:dev() └─→ dev:int ID of device containing file. On Windows NT this is set to NtByHandleFileInformation::VolumeSerialNumber. unix.Stat:rdev() └─→ rdev:int Information about device type. This value may be set to 0 or -1 for files that aren't devices, depending on the operating system. unix.major() and unix.minor() may be used to extract the device numbers. ──────────────────────────────────────────────────────────────────────────────── UNIX STATFS OBJECT unix.Statfs objects are created by statfs() or fstatfs(). The following accessor methods are available. unix.Statfs:fstypename() └─→ str Type of filesystem. Here's some examples of likely values: - `"ext"` on Linux - `"xfs"` on RHEL7 - `"apfs"` on Apple - `"zfs"` on FreeBSD - `"ffs"` on NetBSD and OpenBSD - `"NTFS"` on Windows unix.Statfs:type() └─→ int Type of filesystem. This is a platform-specific magic number. Consider using the unix.Statfs:fstypename() method instead. On Windows, this will actually be a Knuth multiplicative hash of the name. unix.Statfs:bsize() └─→ int Optimal transfer block size. This field serves two purposes: 1. It tells you how to chunk i/o operations. For local disks, it'll likely be any value between 512 and 4096 depending on the operating system. For network filesystems it will likely be a much larger value, e.g. 512kb. 2. It can be multiplied with the fields `blocks`, `bfree`, and `bavail` to obtain a byte count. unix.Statfs:blocks() └─→ int Total data blocks in filesystem. The size of a block is measured as unix.Statfs:bsize(). unix.Statfs:bfree() └─→ int Total free blocks in filesystem. The size of a block is measured as unix.Statfs:bsize(). unix.Statfs:bavail() └─→ int Total free blocks available in filesystem to unprivileged users. The size of a block is measured as unix.Statfs:bsize(). unix.Statfs:files() └─→ int Total file nodes in filesystem. On Windows this is always the maximum integer value. unix.Statfs:ffree() └─→ int Total free file nodes in filesystem. On Windows this is always the maximum integer value. unix.Statfs:fsid() └─→ int Filesystem id. unix.Statfs:namelen() └─→ int Maximum length of filename components in bytes. unix.Statfs:flags() └─→ int Filesystem flags. The following flags are defined: - `ST_RDONLY`: Read-only filesystem (Linux/Windows/XNU/BSDs) - `ST_NOSUID`: Setuid binaries forbidden (Linux/XNU/BSDs) - `ST_NODEV`: Device files forbidden (Linux/XNU/BSDs) - `ST_NOEXEC`: Execution forbidden (Linux/XNU/BSDs) - `ST_SYNCHRONOUS`: Synchronous (Linux/XNU/BSDs) - `ST_NOATIME`: No access time (Linux/XNU/BSDs) - `ST_RELATIME`: Relative access time (Linux/NetBSD) - `ST_APPEND`: Linux-only - `ST_IMMUTABLE`: Linux-only - `ST_MANDLOCK`: Linux-only - `ST_NODIRATIME`: Linux-only - `ST_WRITE`: Linux-only unix.Statfs:owner() └─→ int User id of owner of filesystem mount. On Linux this is always 0 for root. On Windows this is always 0. ──────────────────────────────────────────────────────────────────────────────── UNIX SIGSET OBJECT The unix.Sigset class defines a mutable bitset that may currently contain 128 entries. See `unix.NSIG` to find out how many signals your operating system actually supports. unix.Sigset(sig:int, ...) └─→ unix.Sigset Constructs new signal bitset object. unix.Sigset:add(sig:int) Adds signal to bitset. unix.Sigset:remove(sig:int) Removes signal from bitset. unix.Sigset:fill() Sets all bits in signal bitset to true. unix.Sigset:clear() Sets all bits in signal bitset to false. unix.Sigset:contains(sig:int) └─→ bool Returns true if `sig` is member of signal bitset. unix.Sigset:__repr() unix.Sigset:__tostring() Returns Lua code string that recreates object. ──────────────────────────────────────────────────────────────────────────────── UNIX SIGNAL MAGNUMS unix.SIGINT Terminal CTRL-C keystroke. unix.SIGQUIT Terminal CTRL-\ keystroke. unix.SIGHUP Terminal hangup or daemon reload; auto-broadcasted to process group. unix.SIGILL Illegal instruction. unix.SIGTRAP INT3 instruction. unix.SIGABRT Process aborted. unix.SIGBUS Valid memory access that went beyond underlying end of file. unix.SIGFPE Illegal math. unix.SIGKILL Terminate with extreme prejudice. unix.SIGUSR1 Do whatever you want. unix.SIGUSR2 Do whatever you want. unix.SIGSEGV Invalid memory access. unix.SIGPIPE Write to closed file descriptor. unix.SIGALRM Sent by setitimer(). unix.SIGTERM Terminate. unix.SIGCHLD Child process exited or terminated and is now a zombie (unless this is SIG_IGN or SA_NOCLDWAIT) or child process stopped due to terminal i/o or profiling/debugging (unless you used SA_NOCLDSTOP) unix.SIGCONT Child process resumed from profiling/debugging. unix.SIGSTOP Child process stopped due to profiling/debugging. unix.SIGTSTP Terminal CTRL-Z keystroke. unix.SIGTTIN Terminal input for background process. unix.SIGTTOU Terminal output for background process. unix.SIGXCPU CPU time limit exceeded. unix.SIGXFSZ File size limit exceeded. unix.SIGVTALRM Virtual alarm clock. unix.SIGPROF Profiling timer expired. unix.SIGWINCH Terminal resized. unix.SIGPWR Not implemented in most community editions of system five. ──────────────────────────────────────────────────────────────────────────────── UNIX ERRNO OBJECT This object is returned by system calls that fail. We prefer returning an object because for many system calls, an error is part their normal operation. For example, it's often desirable to use the errno() method when performing a read() to check for EINTR. unix.Errno:errno() └─→ errno:int Returns error magic number. The error number is always different for different platforms. On UNIX systems, error numbers occupy the range [1,127] in practice. The System V ABI reserves numbers as high as 4095. On Windows NT, error numbers can go up to 65535. unix.Errno:winerr() └─→ errno:int Returns Windows error number. On UNIX systems this is always 0. On Windows NT this will normally be the same as errno(). Because Windows defines so many error codes, there's oftentimes a multimapping between its error codes and System Five. In those cases, this value reflect the GetLastError() result at the time the error occurred. unix.Errno:name() └─→ symbol:str Returns string of symbolic name of System Five error code. For example, this might return `"EINTR"`. unix.Errno:call() └─→ symbol:str Returns name of system call that failed. For example, this might return `"read"` if read() was what failed. unix.Errno:doc() └─→ symbol:str Returns English string describing System Five error code. For example, this might return `"Interrupted system call"`. unix.Errno:__tostring() └─→ str Returns verbose string describing error. Different information components are delimited by slash. For example, this might return `"EINTR/4/Interrupted system call"`. On Windows NT this will include additional information about the Windows error (including FormatMessage() output) if the WIN32 error differs from the System Five error code. ──────────────────────────────────────────────────────────────────────────────── UNIX ERROR MAGNUMS unix.EINVAL Invalid argument. Raised by [pretty much everything]. unix.ENOSYS System call not available on this platform. On Windows this is Raised by chroot, setuid, setgid, getsid, setsid. unix.ENOENT No such file or directory. Raised by access, bind, chdir, chmod, chown, chroot, clock_getres, execve, opendir, inotify_add_watch, link, mkdir, mknod, open, readlink, rename, rmdir, stat, swapon, symlink, truncate, unlink, utime, utimensat. unix.ENOTDIR Not a directory. This means that a directory component in a supplied path *existed* but wasn't a directory. For example, if you try to `open("foo/bar")` and `foo` is a regular file, then `ENOTDIR` will be returned. Raised by open, access, chdir, chroot, execve, link, mkdir, mknod, opendir, readlink, rename, rmdir, stat, symlink, truncate, unlink, utimensat, bind, chmod, chown, fcntl, futimesat, inotify_add_watch. unix.EINTR The greatest of all errnos; crucial for building real time reliable software. Raised by accept, clock_nanosleep, close, connect, dup, fcntl, flock, getrandom, nanosleep, open, pause, poll, ptrace, read, recv, select, send, sigsuspend, sigwaitinfo, truncate, wait, write. unix.EIO Raised by access, acct, chdir, chmod, chown, chroot, close, copy_file_range, execve, fallocate, fsync, ioperm, link, madvise, mbind, pciconfig_read, ptrace, read, readlink, sendfile, statfs, symlink, sync_file_range, truncate, unlink, write. unix.ENXIO No such device or address. Raised by lseek, open, prctl unix.E2BIG Argument list too long. Raised by execve, sched_setattr. unix.ENOEXEC Exec format error. Raised by execve, uselib. unix.ECHILD No child process. Raised by wait, waitpid, waitid, wait3, wait4. unix.ESRCH No such process. Raised by getpriority, getrlimit, getsid, ioprio_set, kill, setpgid, tkill, utimensat. unix.EBADF Bad file descriptor; cf. EBADFD. Raised by accept, access, bind, chdir, chmod, chown, close, connect, copy_file_range, dup, fcntl, flock, fsync, futimesat, opendir, getpeername, getsockname, getsockopt, ioctl, link, listen, lseek, mkdir, mknod, mmap, open, prctl, read, readahead, readlink, recv, rename, select, send, shutdown, splice, stat, symlink, sync, sync_file_range, timerfd_create, truncate, unlink, utimensat, write. unix.EAGAIN Resource temporarily unavailable (e.g. SO_RCVTIMEO expired, too many processes, too much memory locked, read or write with O_NONBLOCK needs polling, etc.). Raised by accept, connect, fcntl, fork, getrandom, mincore, mlock, mmap, mremap, poll, read, select, send, setresuid, setreuid, setuid, sigwaitinfo, splice, tee, timer_create, timerfd_create, tkill, write, unix.EPIPE Broken pipe. Returned by write, send. This happens when you try to write data to a subprocess via a pipe but the reader end has already closed, possibly because the process died. Normally i/o routines only return this if `SIGPIPE` doesn't kill the process. Unlike default UNIX programs, redbean currently ignores `SIGPIPE` by default, so this error code is a distinct possibility when pipes or sockets are being used. unix.ENAMETOOLONG Filename too long. Cosmopolitan Libc currently defines `PATH_MAX` as 1024 characters. On UNIX that limit should only apply to system call wrappers like realpath. On Windows NT it's observed by all system calls that accept a pathname. Raised by access, bind, chdir, chmod, chown, chroot, execve, gethostname, link, mkdir, mknod, open, readlink, rename, rmdir, stat, symlink, truncate, unlink, utimensat. unix.EACCES Permission denied. Raised by access, bind, chdir, chmod, chown, chroot, clock_getres, connect, execve, fcntl, getpriority, link, mkdir, mknod, mmap, mprotect, msgctl, open, prctl, ptrace, readlink, rename, rmdir, semget, send, setpgid, socket, stat, symlink, truncate, unlink, uselib, utime, utimensat. unix.ENOMEM We require more vespene gas. Raised by access, bind, chdir, chmod, chown, chroot, clone, copy_file_range, execve, fanotify_init, fork, getgroups, getrlimit, link, mbind, mincore, mkdir, mknod, mlock, mmap, mprotect, mremap, msync, open, poll, readlink, recv, rename, rmdir, select, send, sigaltstack, splice, stat, subpage_prot, swapon, symlink, sync_file_range, tee, timer_create, timerfd_create, unlink. unix.EPERM Operation not permitted. Raised by accept, chmod, chown, chroot, copy_file_range, execve, fallocate, fanotify_init, fcntl, futex, get_robust_list, getdomainname, getgroups, gethostname, getpriority, getrlimit, getsid, gettimeofday, idle, init_module, io_submit, ioctl_console, ioctl_ficlonerange, ioctl_fideduperange, ioperm, iopl, ioprio_set, keyctl, kill, link, lookup_dcookie, madvise, mbind, membarrier, migrate_pages, mkdir, mknod, mlock, mmap, mount, move_pages, msgctl, nice, open, open_by_handle_at, pciconfig_read, perf_event_open, pidfd_getfd, pidfd_send_signal, pivot_root, prctl, process_vm_readv, ptrace, quotactl, reboot, rename, request_key, rmdir, rt_sigqueueinfo, sched_setaffinity, sched_setattr, sched_setparam, sched_setscheduler, seteuid, setfsgid, setfsuid, setgid, setns, setpgid, setresuid, setreuid, setsid, setuid, setup, setxattr, sigaltstack, spu_create, stime, swapon, symlink, syslog, truncate, unlink, utime, utimensat, write. unix.ENOTBLK Block device required. Raised by umount. unix.EBUSY Device or resource busy. Raised by dup, fcntl, msync, prctl, ptrace, rename, rmdir. unix.EEXIST File exists. Raised by link, mkdir, mknod, mmap, open, rename, rmdir, symlink unix.EXDEV Improper link. Raised by copy_file_range, link, rename. unix.ENODEV No such device. Raised by arch_prctl, mmap, open, prctl, timerfd_create. unix.EISDIR Is a directory. Raised by copy_file_range, execve, open, read, rename, truncate, unlink. unix.ENFILE Too many open files in system. Raised by accept, execve, mmap, open, pipe, socket, socketpair, swapon, timerfd_create, uselib, userfaultfd. unix.EMFILE Too many open files. Raised by accept, dup, execve, fcntl, open, pipe, socket, socketpair, timerfd_create. unix.ENOTTY Inappropriate i/o control operation. Raised by ioctl. unix.ETXTBSY Won't open executable that's executing in write mode. Raised by access, copy_file_range, execve, mmap, open, truncate. unix.EFBIG File too large. Raised by copy_file_range, open, truncate, write. unix.ENOSPC No space left on device. Raised by copy_file_range, fsync, link, mkdir, mknod, open, rename, symlink, sync_file_range, write. unix.EDQUOT Disk quota exceeded. Raised by link, mkdir, mknod, open, rename, symlink, write. unix.ESPIPE Invalid seek. Raised by lseek, splice, sync_file_range. unix.EROFS Read-only filesystem. Raised by access, bind, chmod, chown, link, mkdir, mknod, open, rename, rmdir, symlink, truncate, unlink, utime, utimensat. unix.EMLINK Too many links; raised by link, mkdir, rename. unix.ERANGE Result too large. Raised by prctl. unix.EDEADLK Resource deadlock avoided. Raised by fcntl. unix.ENOLCK No locks available. Raised by fcntl, flock. unix.ENOTEMPTY Directory not empty. Raised by rmdir. unix.ELOOP Too many levels of symbolic links. Raised by access, bind, chdir, chmod, chown, chroot, execve, link, mkdir, mknod, open, readlink, rename, rmdir, stat, symlink, truncate, unlink, utimensat. unix.ENOMSG Raised by msgop. unix.EIDRM Identifier removed. Raised by msgctl. unix.ETIME Timer expired; timer expired. Raised by connect. unix.EPROTO Raised by accept, connect, socket, socketpair. unix.EOVERFLOW Raised by copy_file_range, fanotify_init, lseek, mmap, open, stat, statfs unix.ENOTSOCK Not a socket. Raised by accept, bind, connect, getpeername, getsockname, getsockopt, listen, recv, send, shutdown. unix.EDESTADDRREQ Destination address required. Raised by send, write. unix.EMSGSIZE Message too long. Raised by send. unix.EPROTOTYPE Protocol wrong type for socket. Raised by connect. unix.ENOPROTOOPT Protocol not available. Raised by getsockopt, accept. unix.EPROTONOSUPPORT Protocol not supported. Raised by socket, socketpair. unix.ESOCKTNOSUPPORT Socket type not supported. unix.ENOTSUP Operation not supported. Raised by chmod, clock_getres, clock_nanosleep, timer_create. unix.EOPNOTSUPP Socket operation not supported. Raised by accept, listen, mmap, prctl, readv, send, socketpair. unix.EPFNOSUPPORT Protocol family not supported. unix.EAFNOSUPPORT Address family not supported. Raised by connect, socket, socketpair unix.EADDRINUSE Address already in use. Raised by bind, connect, listen unix.EADDRNOTAVAIL Address not available. Raised by bind, connect. unix.ENETDOWN Network is down. Raised by accept unix.ENETUNREACH Host is unreachable. Raised by accept, connect unix.ENETRESET Connection reset by network. unix.ECONNABORTED Connection reset before accept. Raised by accept. unix.ECONNRESET Connection reset by client. Raised by send. unix.ENOBUFS No buffer space available; raised by getpeername, getsockname, send. unix.EISCONN Socket is connected. Raised by connect, send. unix.ENOTCONN Socket is not connected. Raised by getpeername, recv, send, shutdown. unix.ESHUTDOWN Cannot send after transport endpoint shutdown; note that shutdown write is an `EPIPE`. unix.ETOOMANYREFS Too many references: cannot splice. Raised by sendmsg. unix.ETIMEDOUT Connection timed out. Raised by connect. unix.ECONNREFUSED System-imposed limit on the number of threads was encountered. Raised by connect, listen, recv. unix.EHOSTDOWN Host is down. Raised by accept. unix.EHOSTUNREACH Host is unreachable. Raised by accept. unix.EALREADY Connection already in progress. Raised by connect, send. unix.ENODATA No message is available in xsi stream or named pipe is being closed; no data available; barely in posix; returned by ioctl; very close in spirit to EPIPE? ──────────────────────────────────────────────────────────────────────────────── UNIX MISCELLANEOUS MAGNUMS unix.ARG_MAX Returns maximum length of arguments for new processes. This is the character limit when calling execve(). It's the sum of the lengths of `argv` and `envp` including any nul terminators and pointer arrays. For example to see how much your shell `envp` uses $ echo $(($(env | wc -c) + 1 + ($(env | wc -l) + 1) * 8)) 758 POSIX mandates this be 4096 or higher. On Linux this it's 128*1024. On Windows NT it's 32767*2 because CreateProcess lpCommandLine and environment block are separately constrained to 32,767 characters. Most other systems define this limit much higher. unix.BUFSIZ Returns default buffer size. The UNIX module does not perform any buffering between calls. Each time a read or write is performed via the UNIX API your redbean will allocate a buffer of this size by default. This current default would be 4096 across platforms. unix.CLK_TCK Returns the scheduler frequency. This is granularity at which the kernel does work. For example, the Linux kernel normally operates at 100hz so its CLK_TCK will be 100. This value is useful for making sense out of unix.Rusage data. unix.PIPE_BUF Returns maximum size at which pipe i/o is guaranteed atomic. POSIX requires this be at least 512. Linux is more generous and allows 4096. On Windows NT this is currently 4096, and it's the parameter redbean passes to CreateNamedPipe(). unix.PATH_MAX Returns maximum length of file path. This applies to a complete path being passed to system calls. POSIX.1 XSI requires this be at least 1024 so that's what most platforms support. On Windows NT, the limit is technically 260 characters. Your redbean works around that by prefixing `//?/` to your paths as needed. On Linux this limit will be 4096, but that won't be the case for functions such as realpath that are implemented at the C library level; however such functions are the exception rather than the norm, and report enametoolong(), when exceeding the libc limit. unix.NAME_MAX Returns maximum length of file path component. POSIX requires this be at least 14. Most operating systems define it as 255. It's a good idea to not exceed 253 since that's the limit on DNS labels. unix.NSIG Returns maximum number of signals supported by underlying system. The limit for unix.Sigset is 128 to support FreeBSD, but most operating systems define this much lower, like 32. This constant reflects the value chosen by the underlying operating system. ──────────────────────────────────────────────────────────────────────────────── LEGAL redbean contains software licensed ISC, MIT, BSD-2, BSD-3, zlib which makes it a permissively licensed gift to anyone who might find it useful. The transitive closure of legalese can be found inside the binary structure, because notice licenses require we distribute the license along with any software that uses it. By putting them in the binary, compliance in automated and no need for further action on the part of the user who is distributing. ──────────────────────────────────────────────────────────────────────────────── SEE ALSO https://redbean.dev/ https://news.ycombinator.com/item?id=26271117