watchexec
Software development often involves running the same commands over and over. Boring!
watchexec
is a simple, standalone tool that watches a path and runs a command whenever it detects modifications.
Example use cases:
- Automatically run unit tests
- Run linters/syntax checkers
Features
- Simple invocation and use
- Runs on OS X, Linux, and Windows
- Monitors current directory and all subdirectories for changes
- Uses most efficient event polling mechanism for your platform (except for BSD)
- Coalesces multiple filesystem events into one, for editors that use swap/backup files during saving
- By default, uses
.gitignore
and.ignore
to determine which files to ignore notifications for - Support for watching files with a specific extension
- Support for filtering/ignoring events based on glob patterns
- Launches child processes in a new process group
- Sets the following environment variables in the child process:
- If a single file changed (depending on the event type):
$WATCHEXEC_CREATED_PATH
, the path of the file that was created$WATCHEXEC_REMOVED_PATH
, the path of the file that was removed$WATCHEXEC_RENAMED_PATH
, the path of the file that was renamed$WATCHEXEC_WRITTEN_PATH
, the path of the file that was modified$WATCHEXEC_META_CHANGED_PATH
, the path of the file whose metadata changed
- If multiple files changed:
$WATCHEXEC_COMMON_PATH
, the longest common path of all of the files that triggered a change
- This can be disabled or limited with
--no-environment
and--no-meta
- If a single file changed (depending on the event type):
- Optionally clears screen between executions
- Optionally restarts the command with every modification (good for servers)
- Does not require a language runtime
Anti-Features
- Not tied to any particular language or ecosystem
- Does not require a cryptic command line involving
xargs
Usage Examples
Watch all JavaScript, CSS and HTML files in the current directory and all subdirectories for changes, running make
when a change is detected:
$ watchexec --exts js,css,html make
Call make test
when any file changes in this directory/subdirectory, except for everything below target
:
$ watchexec -i target make test
Call ls -la
when any file changes in this directory/subdirectory:
$ watchexec -- ls -la
Call/restart python server.py
when any Python file in the current directory (and all subdirectories) changes:
$ watchexec -e py -r python server.py
Call/restart my_server
when any file in the current directory (and all subdirectories) changes, sending SIGKILL
to stop the child process:
$ watchexec -r -s SIGKILL my_server
Send a SIGHUP to the child process upon changes (Note: with using -n | --no-shell
here, we're executing my_server
directly, instead of wrapping it in a shell:
$ watchexec -n -s SIGHUP my_server
Run make
when any file changes, using the .gitignore
file in the current directory to filter:
$ watchexec make
Run make
when any file in lib
or src
changes:
$ watchexec -w lib -w src make
Run bundle install
when the Gemfile
changes:
$ watchexec -w Gemfile bundle install
Installation
All platforms
Cargo
Requires Rust 1.38 or later.
$ cargo install watchexec
Pre-built
Use the GitHub Releases tab to obtain the tarball/zipfile appropriate for your platform and architecture, extract it, and place it in your PATH
.
macOS
Homebrew
$ brew install watchexec
Webi
$ curl -sS https://webinstall.dev/watchexec | bash
Linux
PRs for packaging in unsupported distros are welcome.
Debian
A deb package is available for amd64 architectures in the GitHub Releases.
Arch Linux
Available in the community repository:
$ pacman -S watchexec
Webi
$ curl -sS https://webinstall.dev/watchexec/ | bash
Windows
Scoop
#> scoop install watchexec
Chocolatey
#> choco install watchexec
Webi
#> curl.exe -A MS https://webinstall.dev/watchexec | powershell
Shell completions
Currently available shell completions:
- zsh:
completions/zsh
should be installed to/usr/share/zsh/site-functions/_watchexec