Monitor a Folder OSX for file changes then run a bash script

Question

Possible Duplicate:
Watch Filesystem in Real Time on OS X and Ubuntu

I'm looking for a efficient method to monitor a local directory in OSX and if any files have been changed in that directory run a bash script to commit the files to github.

Any recommend tools for monitoring a directory for file changes, then triggering an action, i.e. a bash script?

Answer 1

Using fswatch from your repository:

fswatch . 'git commit -avm "snapshot at ${date}"'

This simple example would only catch changes to files already in the repository.

Answer 2

One option would be to just use launchd. Save a property list like this as ~/Library/LaunchAgents/com.superuser.445907.plist, and load it with launchctl load ~/Library/LaunchAgents/com.superuser.445907.plist or by logging out and back in.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC -//Apple Computer//DTD PLIST 1.0//EN
http://www.apple.com/DTDs/PropertyList-1.0.dtd>
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.superuser.445907</string>
    <key>Program</key>
    <string>/Users/username/script</string> <!-- ~/ doesn't work -->
    <key>WatchPaths</key>
    <array>
        <string>/Users/username/Folder/</string>
    </array>
    <key>ThrotteInterval</key>
    <integer>0</integer> <!-- run at most every 0 seconds, by default 10 -->
</dict>
</plist>

Launchd only registers changes to files when they are saved atomically, or deleted and recreated every time they are saved. Most OS X applications perform atomic saves by default, but for example TextMate and vim don't. Changes in subfolders of watched folders aren't detected.

launchctl unload $path && launchctl load $path applies changes to a plist.

See man launchd and man launchd.plist for more information.