34

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>

4 Answers 4

30

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>

See: Creating Launch Daemons and Agents.

1
  • 4
    Sure, you can hard code your env. vars in the plist, but you can't use existing vars like $HOME. Unless it's just an argument to a shell script, in which case the shell (not launchd), will expand it. But in this example, it might actually work if you add the -c option to /bin/sh ?
    – mivk
    Jul 12, 2012 at 20:04
6

The best way to handle this is by wrapping your command in a shell. For example:

<?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>KeepAlive</key>
    <false/>
    <key>Label</key>
    <string>sh.daniel.envvar</string>
    <key>ProgramArguments</key>
    <array>
        <string>/bin/zsh</string>
        <string>-c</string>
        <string>echo 'You did the thing!' > $HOME/did-the-thing.log</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>
❯ cat ~/did-the-thing.log
You did the thing!

The flag -c tells ZSH (and Bash, and sh) to run the command specified in your next. If you add the flag -l, it’ll load your dotfiles before executing, just as a normal login shell does.

2
  • Thank you for your mention of -l! That's the piece I was missing... I have some paths in my .profile that weren't there until I added the -l option.
    – Jesse
    Apr 4, 2022 at 18:42
  • Note: /bin/sh does not support -l option. At least not on my system.
    – Jesse
    Apr 4, 2022 at 20:09
3

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...

1

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>
3
  • 1
    This doesn't work. I get "/bin/sh: ~/bin/attach-devroot.sh: No such file or directory"
    – matpie
    Feb 17, 2010 at 0:56
  • This only works if the EnableGlobbing flag is set to true. See the launchd.plist man page.
    – sakra
    Jun 2, 2012 at 18:45
  • 2
    EnableGlobbing not supported anymore
    – Liviu
    Jun 27, 2018 at 13:19

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