Is there a command like "watch" or "inotifywait" on the Mac?

Question

I want to watch a folder on my Mac (Snow Leopard) and then execute a script (giving it the filename of what was just moved into a folder (as a parameter... x.sh "filename")).

I have a script all written up in bash (x.sh) that will move some files and other stuff on input $1 I just need OSX to give me the file name when new files/folders are moved/created into a dir.

Any such command?

Answer 1

Apple OSX Folder Actions allow you to automate tasks based on actions taken on a folder.

Answer 2

You can use launchd for that purpose. Launchd can be configured to automatically launch a program when a file path is modified.

For example the following launchd config plist will launch the program /usr/bin/logger when the desktop folder of my user account is modified:

<?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"&gt;
<plist version="1.0">
<dict>
    <key>Label</key>
 <string>logger</string>
 <key>ProgramArguments</key>
 <array>
  <string>/usr/bin/logger</string>
  <string>path modified</string>
 </array>
 <key>WatchPaths</key>
 <array>
  <string>/Users/sakra/Desktop/</string>
 </array>
</dict>
</plist>

To activate the config plist save it to the LaunchAgents folder in your Library folder as "logger.plist".

From the shell you can then use the command launchctl to activate the logger.plist by running:

launchctl load ~/Library/LaunchAgents/logger.plist

The desktop folder is now being monitored. Every time it is changed you should see an output in the system.log (use Console.app). To deactivate the logger.plist, run:

launchctl unload ~/Library/LaunchAgents/logger.plist

The configuration file above uses the WatchPaths option. Alternatively you can also use the QueueDirectories option. See the launchd man page for more information.