Recursively monitors the current directory for changes, executing the command when a filesystem change is detected (among other event sources). By default, watchexec uses efficient kernel\-level mechanisms to watch for changes.
By default, Watchexec watches the current directory.
When watching a single file, it\*(Aqs often better to watch the containing directory instead, and filter on the filename. Some editors may replace the file with a new one when saving, and some platforms may not detect that or further changes.
Upon starting, Watchexec resolves a "project origin" from the watched paths. See the help for \*(Aq\-\-project\-origin\*(Aq for more information.
This option can be specified multiple times to watch multiple files or directories.
The special value \*(Aq/dev/null\*(Aq, provided as the only path watched, will cause Watchexec to not watch any paths. Other event sources (like signals or key events) may still be used.
What to do when receiving events while the command is running
Default is to \*(Aqqueue\*(Aq up events and run the command once again when the previous run has finished. You can also use \*(Aqdo\-nothing\*(Aq, which ignores events while the command is running and may be useful to avoid spurious changes made by that command, or \*(Aqrestart\*(Aq, which terminates the running command and starts a new one. Finally, there\*(Aqs \*(Aqsignal\*(Aq, which only sends a signal; this can be useful with programs that can reload their configuration without a full restart.
The signal can be specified with the \*(Aq\-\-signal\*(Aq option.
Note that this option is scheduled to change its default to \*(Aqdo\-nothing\*(Aq in the next major release. File an issue if you have any concerns.
Send a signal to the process when it\*(Aqs still running
Specify a signal to send to the process when it\*(Aqs still running. This implies \*(Aq\-\-on\-busy\-update=signal\*(Aq; otherwise the signal used when that mode is \*(Aqrestart\*(Aq is controlled by \*(Aq\-\-stop\-signal\*(Aq.
See the long documentation for \*(Aq\-\-stop\-signal\*(Aq for syntax.
Signals are not supported on Windows at the moment, and will always be overridden to \*(Aqkill\*(Aq. See \*(Aq\-\-stop\-signal\*(Aq for more on Windows "signals".
This is used by \*(Aqrestart\*(Aq and \*(Aqsignal\*(Aq modes of \*(Aq\-\-on\-busy\-update\*(Aq (unless \*(Aq\-\-signal\*(Aq is provided). The restart behaviour is to send the signal, wait for the command to exit, and if it hasn\*(Aqt exited after some time (see \*(Aq\-\-timeout\-stop\*(Aq), forcefully terminate it.
The default on unix is "SIGTERM".
Input is parsed as a full signal name (like "SIGTERM"), a short signal name (like "TERM"), or a signal number (like "15"). All input is case\-insensitive.
On Windows this option is technically supported but only supports the "KILL" event, as Watchexec cannot yet deliver other events. Windows doesn\*(Aqt have signals as such; instead it has termination (here called "KILL" or "STOP") and "CTRL+C", "CTRL+BREAK", and "CTRL+CLOSE" events. For portability the unix signals "SIGKILL", "SIGINT", "SIGTERM", and "SIGHUP" are respectively mapped to these.
This is used by the \*(Aqrestart\*(Aq mode of \*(Aq\-\-on\-busy\-update\*(Aq. After the graceful stop signal is sent, Watchexec will wait for the command to exit. If it hasn\*(Aqt exited after this time, it is forcefully terminated.
Takes a unit\-less value in seconds, or a time span value such as "5min 20s".
The default is 60 seconds. Set to 0 to immediately force\-kill the command.
Takes a pair of signal names, separated by a colon, such as "TERM:INT" to map SIGTERM to SIGINT. The first signal is the one received by watchexec, and the second is the one sent to the command. The second can be omitted to discard the first signal, such as "TERM:" to not do anything on SIGTERM.
If SIGINT or SIGTERM are mapped, then they no longer quit Watchexec. Besides making it hard to quit Watchexec itself, this is useful to send pass a Ctrl\-C to the command without also terminating Watchexec and the underlying program with it, e.g. with "INT:INT".
Signal syntax is case\-insensitive for short names (like "TERM", "USR2") and long names (like "SIGKILL", "SIGHUP"). Signal numbers are also supported (like "15", "31"). On Windows, the forms "STOP", "CTRL+C", and "CTRL+BREAK" are also supported to receive, but Watchexec cannot yet deliver other "signals" than a STOP.
When an event is received, Watchexec will wait for up to this amount of time before handling it (such as running the command). This is essential as what you might perceive as a single change may actually emit many events, and without this behaviour, Watchexec would run much too often. Additionally, it\*(Aqs not infrequent that file writes are not atomic, and each write may emit an event, so this is a good way to avoid running a command while a file is partially written.
An alternative use is to set a high value (like "30min" or longer), to save power or bandwidth on intensive tasks, like an ad\-hoc backup script. In those use cases, note that every accumulated event will build up in memory.
Takes a unit\-less value in milliseconds, or a time span value such as "5sec 20ms".
The default is 50 milliseconds. Setting to 0 is highly discouraged.
This watches the stdin file descriptor for EOF, and exits Watchexec gracefully when it is closed. This is used by some process managers to avoid leaving zombie processes around.
Among other VCS exclude files, like for Mercurial, Subversion, Bazaar, DARCS, Fossil. Note that Watchexec will detect which of these is in use, if any, and only load the relevant files. Both global (like \*(Aq~/.gitignore\*(Aq) and local (like \*(Aq.gitignore\*(Aq) files are considered.
This option is useful if you want to watch files that are ignored by Git.
\- Git (if core.excludesFile is set): the file at that path
\- Git (otherwise): the first found of $XDG_CONFIG_HOME/git/ignore, %APPDATA%/.gitignore, %USERPROFILE%/.gitignore, $HOME/.config/git/ignore, $HOME/.gitignore.
\- Bazaar: the first found of %APPDATA%/Bazzar/2.0/ignore, $HOME/.bazaar/ignore.
\- Watchexec: the first found of $XDG_CONFIG_HOME/watchexec/ignore, %APPDATA%/watchexec/ignore, %USERPROFILE%/.watchexec/ignore, $HOME/.watchexec/ignore.
Watchexec has a set of default ignore patterns, such as editor swap files, `*.pyc`, `*.pyo`, `.DS_Store`, `.bzr`, `_darcs`, `.fossil\-settings`, `.git`, `.hg`, `.pijul`, `.svn`, and Watchexec log files.
This is a shorthand for \*(Aq\-\-no\-global\-ignore\*(Aq, \*(Aq\-\-no\-vcs\-ignore\*(Aq, \*(Aq\-\-no\-project\-ignore\*(Aq, but even more efficient as it will skip all the ignore discovery mechanisms from the get go.
Note that default ignores are still loaded, see \*(Aq\-\-no\-default\-ignore\*(Aq.
By default, Watchexec will run the command once immediately. With this option, it will instead wait until an event is detected before running the command as normal.
This option will cause Watchexec to sleep for the specified amount of time before running the command, after an event is detected. This is like using "sleep 5 && command" in a shell, but portable and slightly more efficient.
Takes a unit\-less value in seconds, or a time span value such as "2min 5s".
By default, and where available, Watchexec uses the operating system\*(Aqs native file system watching capabilities. This option disables that and instead uses a polling mechanism, which is less efficient but can work around issues with some file systems (like network shares) or edge cases.
Optionally takes a unit\-less value in milliseconds, or a time span value such as "2s 500ms", to use as the polling interval. If not specified, the default is 30 seconds.
By default, Watchexec will use \*(Aq$SHELL\*(Aq if it\*(Aqs defined or a default of \*(Aqsh\*(Aq on Unix\-likes, and either \*(Aqpwsh\*(Aq, \*(Aqpowershell\*(Aq, or \*(Aqcmd\*(Aq (CMD.EXE) on Windows, depending on what Watchexec detects is the running shell.
With this option, you can override that and use a different shell, for example one with more features or one which has your custom aliases and functions.
The special value \*(Aqnone\*(Aq can be used to disable shell use entirely. In that case, the command provided to Watchexec will be parsed, with the first word being the executable and the rest being the arguments, and executed directly. Note that this parsing is rudimentary, and may not work as expected in all cases.
Using \*(Aqnone\*(Aq is a little more efficient and can enable a stricter interpretation of the input, but it also means that you can\*(Aqt use shell features like globbing, redirection, control flow, logic, or pipes.
This is a convenience option for using Watchexec as a file watcher, without running any commands. It is almost equivalent to using `cat` as the command, except that it will not spawn a new process for each event.
This option requires `\-\-emit\-events\-to` to be set, and restricts the available modes to `stdio` and `json\-stdio`, modifying their behaviour to write to stdout instead of the stdin of the command.
This is a convenience option for setting environment variables for the command, without setting them for the Watchexec process itself.
Use key=value syntax. Multiple variables can be set by repeating the option.
.TP
\fB\-\-no\-process\-group\fR
Don\*(Aqt use a process group
By default, Watchexec will run the command in a process group, so that signals and terminations are sent to all processes in the group. Sometimes that\*(Aqs not what you want, and you can disable the behaviour with this option.
.TP
\fB\-N\fR, \fB\-\-notify\fR
Alert when commands start and end
With this, Watchexec will emit a desktop notification when a command starts and ends, on supported platforms. On unsupported platforms, it may silently do nothing, or log a warning.
This may not be exactly accurate, as it includes some overhead from Watchexec itself. Use the `time` utility, high\-precision timers, or benchmarking tools for more accurate results.
.TP
\fB\-q\fR, \fB\-\-quiet\fR
Don\*(Aqt print starting and stopping messages
By default Watchexec will print a message when the command starts and stops. This option disables this behaviour, so only the command\*(Aqs output, warnings, and errors will be printed.
Watchexec will attempt to discover the project\*(Aqs "origin" (or "root") by searching for a variety of markers, like files or directory patterns. It does its best but sometimes gets it it wrong, and you can override that with this option.
The project origin is used to determine the path of certain ignore files, which VCS is being used, the meaning of a leading \*(Aq/\*(Aq in filtering patterns, and maybe more in the future.
When set, Watchexec will also not bother searching, which can be significantly faster.
.TP
\fB\-\-workdir\fR=\fIDIRECTORY\fR
Set the working directory
By default, the working directory of the command is the working directory of Watchexec. You can change that with this option. Note that paths may be less intuitive to use with this.
.TP
\fB\-e\fR, \fB\-\-exts\fR=\fIEXTENSIONS\fR
Filename extensions to filter to
This is a quick filter to only emit events for files with the given extensions. Extensions can be given with or without the leading dot (e.g. \*(Aqjs\*(Aq or \*(Aq.js\*(Aq). Multiple extensions can be given by repeating the option or by separating them with commas.
.TP
\fB\-f\fR, \fB\-\-filter\fR=\fIPATTERN\fR
Filename patterns to filter to
Provide a glob\-like filter pattern, and only events for files matching the pattern will be emitted. Multiple patterns can be given by repeating the option. Events that are not from files (e.g. signals, keyboard events) will pass through untouched.
.TP
\fB\-\-filter\-file\fR=\fIPATH\fR
Files to load filters from
Provide a path to a file containing filters, one per line. Empty lines and lines starting with \*(Aq#\*(Aq are ignored. Uses the same pattern format as the \*(Aq\-\-filter\*(Aq option.
This can also be used via the $WATCHEXEC_FILTER_FILES environment variable.
/!\\ This option is EXPERIMENTAL and may change and/or vanish without notice.
Provide your own custom filter programs in jaq (similar to jq) syntax. Programs are given an event in the same format as described in \*(Aq\-\-emit\-events\-to\*(Aq and must return a boolean.
In addition to the jaq stdlib, watchexec adds some custom filter definitions:
\-\*(Aqpath | file_meta\*(Aq returns file metadata or null if the file does not exist.
\-\*(Aqpath | file_size\*(Aq returns the size of the file at path, or null if it does not exist.
\-\*(Aqpath | file_read(bytes)\*(Aq returns a string with the first n bytes of the file at path. If the file is smaller than n bytes, the whole file is returned. There is no filter to read the whole file at once to encourage limiting the amount of data read and processed.
\-\*(Aqstring | hash\*(Aq, and \*(Aqpath | file_hash\*(Aq return the hash of the string or file at path. No guarantee is made about the algorithm used: treat it as an opaque value.
\-\*(Aqany | kv_store(key)\*(Aq, \*(Aqkv_fetch(key)\*(Aq, and \*(Aqkv_clear\*(Aq provide a simple key\-value store. Data is kept in memory only, there is no persistence. Consistency is not guaranteed.
\-\*(Aqany | printout\*(Aq, \*(Aqany | printerr\*(Aq, and \*(Aqany | log(level)\*(Aq will print or log any given value to stdout, stderr, or the log (levels = error, warn, info, debug, trace), and pass the value through (so \*(Aq[1] | log("debug") | .[]\*(Aq will produce a \*(Aq1\*(Aq and log \*(Aq[1]\*(Aq).
All filtering done with such programs, and especially those using kv or filesystem access, is much slower than the other filtering methods. If filtering is too slow, events will back up and stall watchexec. Take care when designing your filters.
If the argument to this option starts with an \*(Aq@\*(Aq, the rest of the argument is taken to be the path to a file containing a jaq program.
Jaq programs are run in order, after all other filters, and short\-circuit: if a filter (jaq or not) rejects an event, execution stops there, and no other filters are run. Additionally, they stop after outputting the first value, so you\*(Aqll want to use \*(Aqany\*(Aq or \*(Aqall\*(Aq when iterating, otherwise only the first item will be processed, which can be quite confusing!
Find user\-contributed programs or submit your own useful ones at <https://github.com/watchexec/watchexec/discussions/592>.
Provide a glob\-like filter pattern, and events for files matching the pattern will be excluded. Multiple patterns can be given by repeating the option. Events that are not from files (e.g. signals, keyboard events) will pass through untouched.
.TP
\fB\-\-ignore\-file\fR=\fIPATH\fR
Files to load ignores from
Provide a path to a file containing ignores, one per line. Empty lines and lines starting with \*(Aq#\*(Aq are ignored. Uses the same pattern format as the \*(Aq\-\-ignore\*(Aq option.
This can also be used via the $WATCHEXEC_IGNORE_FILES environment variable.
.TP
\fB\-\-fs\-events\fR=\fIEVENTS\fR
Filesystem events to filter to
This is a quick filter to only emit events for the given types of filesystem changes. Choose from \*(Aqaccess\*(Aq, \*(Aqcreate\*(Aq, \*(Aqremove\*(Aq, \*(Aqrename\*(Aq, \*(Aqmodify\*(Aq, \*(Aqmetadata\*(Aq. Multiple types can be given by repeating the option or by separating them with commas. By default, this is all types except for \*(Aqaccess\*(Aq.
This may apply filtering at the kernel level when possible, which can be more efficient, but may be more confusing when reading the logs.
.TP
\fB\-\-no\-meta\fR
Don\*(Aqt emit fs events for metadata changes
This is a shorthand for \*(Aq\-\-fs\-events create,remove,rename,modify\*(Aq. Using it alongside the \*(Aq\-\-fs\-events\*(Aq option is non\-sensical and not allowed.
.TP
\fB\-\-print\-events\fR
Print events that trigger actions
This prints the events that triggered the action when handling it (after debouncing), in a human readable form. This is useful for debugging filters.
Use \*(Aq\-v\*(Aq when you need more diagnostic information.
.TP
\fB\-v\fR, \fB\-\-verbose\fR
Set diagnostic log level
This enables diagnostic logging, which is useful for investigating bugs or gaining more insight into faulty filters or "missing" events. Use multiple times to increase verbosity.
Goes up to \*(Aq\-vvvv\*(Aq. When submitting bug reports, default to a \*(Aq\-vvv\*(Aq log level.
You may want to use with \*(Aq\-\-log\-file\*(Aq to avoid polluting your terminal.
Setting $RUST_LOG also works, and takes precedence, but is not recommended. However, using $RUST_LOG is the only way to get logs from before these options are parsed.
This writes diagnostic logs to a file, instead of the terminal, in JSON format. If a log level was not already specified, this will set it to \*(Aq\-vvv\*(Aq.
If a path is not provided, the default is the working directory. Note that with \*(Aq\-\-ignore\-nothing\*(Aq, the write events to the log will likely get picked up by Watchexec, causing a loop; prefer setting a path outside of the watched directory.
If the path provided is a directory, a file will be created in that directory. The file name will be the current date and time, in the format \*(Aqwatchexec.YYYY\-MM\-DDTHH\-MM\-SSZ.log\*(Aq.
This shows the manual page for Watchexec, if the output is a terminal and the \*(Aqman\*(Aq program is available. If not, the manual page is printed to stdout in ROFF format (suitable for writing to a watchexec.1 file).
.TP
\fB\-\-completions\fR=\fICOMPLETIONS\fR
Generate a shell completions script
Provides a completions script or configuration for the given shell. If Watchexec is not distributed with pre\-generated completions, you can use this to generate them yourself.
It\*(Aqs run when events pass filters and the debounce period (and once at startup unless \*(Aq\-\-postpone\*(Aq is given). If you pass flags to the command, you should separate it with \-\- though that is not strictly required.
Examples:
$ watchexec \-w src npm run build
$ watchexec \-w src \-\- rsync \-a src dest
Take care when using globs or other shell expansions in the command. Your shell may expand them before ever passing them to Watchexec, and the results may not be what you expect. Compare:
Behaviour depends on the value of \*(Aq\-\-shell\*(Aq: for all except \*(Aqnone\*(Aq, every part of the command is joined together into one string with a single ascii space character, and given to the shell as described in the help for \*(Aq\-\-shell\*(Aq. For \*(Aqnone\*(Aq, each distinct element the command is passed as per the execvp(3) convention: first argument is the program, as a path or searched for in the \*(AqPATH\*(Aq environment variable, rest are arguments.
.SHEXTRA
Use @argfile as first argument to load arguments from the file \*(Aqargfile\*(Aq (one argument per line) which will be inserted in place of the @argfile (further arguments on the CLI will override or add onto those in the file).
