Use an environment variable in a launchd script

I'm curious if it's possible to specify an envrionment variable in the ProgramArguments portion of a luanchd script on Mac OS X Leopard.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>me.mpietz.MountDevRoot</string>
    <key>ProgramArguments</key>
    <array>
        <string>/bin/sh</string>

        <string>$HOME/bin/attach-devroot.sh</string>

        <!-- Instead of using...
        <string>/Users/mpietz/bin/attach-devroot.sh</string -->
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

From serverfault sirlancelot

• I'm not sure - I haven't tried it before... but I can tell you that if the only variable you care about is home - you can use ~.

  So: <string>~/bin/attach-devroot.sh</string>
  

  sirlancelot : This doesn't work. I get `"/bin/sh: ~/bin/attach-devroot.sh: No such file or directory"`
  From Dave Holland

• I don't think launchd knows about the environment natively, at least not as ${VARIABLE} substitutions.

  There's nothing stopping you from launching a shell script (or a shell with -c) as your launchd action though, and that would have an environment and respect ${VARIABLES} -- Be aware of the difference between System and User daemons/agents in that case though...

  From voretaq7

• Not in the ProgramArguments key. You need to add an EnvironmentVariables key into your plist's dict like so:

  <?xml version="1.0" encoding="UTF-8"?>
  <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
  <plist version="1.0">
  <dict>
      <key>EnvironmentVariables</key>
      <dict>
             <key>AN_ENVIRONMENT_VARIABLE_NAME</key>
             <string>the_value</string>
      </dict>
      <key>Label</key>
      <string>me.mpietz.MountDevRoot</string>
      <key>ProgramArguments</key>
      <array>
          <string>/bin/sh</string>
  
          <string>$HOME/bin/attach-devroot.sh</string>
  
          <!-- Instead of using...
          <string>/Users/mpietz/bin/attach-devroot.sh</string -->
      </array>
      <key>RunAtLoad</key>
      <true/>
  </dict>
  </plist>
  

  From jpb