How can I add arguments to OSX launchd plist to pipe output to a log file?

Question

I have tried many different variation on this but just can\'t get it to work.

I have a plist file:

Answer 1

>> is a shell operator, not a program argument, and launchd doesn't pass its commands through a shell (unless you force it, as in @Lauri's answer). But launchd does have its own option for redirecting stdout:

<key>StandardOutPath</key>
<string>/Users/ilium007/support/scripts/handbrake/logs/handbrake_encode.log</string>

Note that it automatically appends (equivalent to >>, not >). You can also redirect stderr with the StandardErrorPath key. One thing you cannot do is use ~ (as in ~/support/scripts/handbrake/logs/handbrake_encode.log) -- that, again, is a shell feature that launchd doesn't emulate.

Answer 2

The redirection operators can't be used as arguments. You can either make another script for the pipeline or use bash -c.

<string>bash</string>
<string>-c</string>
<string>bash ~/Desktop/test.sh >> ~/Desktop/test</string>

Answer 3

The standard out and error keys are very useful, I redirected mine to the first terminal/shell as follows:

<key>StandardOutPath</key>
<string>/dev/ttys000</string>
<key>StandardErrorPath</key>
<string>/dev/ttys000</string>

You can change ttys000 to another number (ttys001..2) if you have multiple terminals. You can find the terminal id by typing in the shell:

tty

This helped me to find out why I was getting console errors in OS X, I needed to have the full path for every command and full paths for directories I was CD'ing to in scripts.

for instance grep is:

/usr/bin/grep

and commands installed by macports use other paths also, like:

/opt/local/bin/lynx

I also tried to chown root:wheel the plist, but this doesn't seem to be necessary, but probably not a bad idea to prevent someone from editing it to whatever...

edit:changed mine back to normal user after I got some permission errors which turned out to be because the script was trying to make files in / without permission, needed to add full paths to output files too, which is weird as it worked the previous day.