Fast cross-platform command line utility to watch file system changes.
The underlying watch library is Chokidar, which is one of the best watch utilities for Node. Chokidar is battle-tested:
If you need it only with NPM scripts:
npm install chokidar-cli
npm install -g chokidar-cli
chokidar streams changes for all patterns to stdout:
$ chokidar '**/.js' '**/*.less' change:test/dir/a.js change:test/dir/a.less add:test/b.js unlink:test/b.js
Each change is represented with format
event:relativepath. Possible events:
Output only relative paths on each change
$ chokidar '**/.js' '**/*.less' | cut -d ':' -f 2- test/dir/a.js test/dir/a.less test/b.js test/b.js
Run npm run build-js whenever any .js file changes in the current work directory tree
chokidar '**/*.js' -c 'npm run build-js'
Watching in network directories must use polling
chokidar '**/*.less' -c 'npm run build-less' --polling
Usage: chokidar <pattern> [<pattern>...] [options] <pattern>: Glob pattern to specify files to be watched. Multiple patterns can be watched by separating patterns with spaces. To prevent shell globbing, write pattern inside quotes. Guide to globs: https://github.com/isaacs/node-glob#glob-primer Options: -c, --command Command to run after each change. Needs to be surrounded with quotes when command contains spaces -d, --debounce Debounce timeout in ms for executing command [default: 400] -t, --throttle Throttle timeout in ms for executing command [default: 0] -s, --follow-symlinks When not set, only the symlinks themselves will be watched for changes instead of following the link references and bubbling events through the links path [boolean] [default: false] -i, --ignore Pattern for files which should be ignored. Needs to be surrounded with quotes to prevent shell globbing. The whole relative or absolute path is tested, not just filename. Supports glob patters or regexes using format: /yourmatch/i --initial When set, command is initially run once [boolean] [default: false] -p, --polling Whether to use fs.watchFile(backed by polling) instead of fs.watch. This might lead to high CPU utilization. It is typically necessary to set this to true to successfully watch files over a network, and it may be necessary to successfully watch files in other non- standard situations [boolean] [default: false] --poll-interval Interval of file system polling. Effective when -- polling is set [default: 100] --poll-interval-binary Interval of file system polling for binary files. Effective when --polling is set [default: 300] --verbose When set, output is more verbose and human readable. [boolean] [default: false] --silent When set, internal messages of chokidar-cli won't be written. [boolean] [default: false] -h, --help Show help [boolean] -v, --version Show version number [boolean] Examples: chokidar "**/*.js" -c "npm run build-js" build when any .js file changes chokidar "**/*.js" "**/*.less" output changes of .js and .less files