Scheduling a terminal command or script file to run daily at a specific time Mac OS X

Question

I want to have my computer set its volume to a specific level every night at 11:45 PM. I'm running OSX 10.11.4. I can set the volume manually through terminal with

osascript -e "set Volume 1.7" 

or as a script with

set volume 1.7 

I want it to be scheduled nightly though. It's hard to find anything online that isn't super outdated. I don't really want to use iCal. From what I've found online, launchd is the way to go, but as a noob, I don't know where to start.

I see things about using a .plist in /Library/LaunchAgents. So I found a nifty plist generator Launched.zerowidth.com but what kind of code do I put in the plist to get the desired effect? I'm also questioning if this is the correct path for this to execute if any user is logged on.

Am I going down the wrong path here? I'm open to any ideas to make this happen, but I don't want to use a 3rd party app that I have to keep open all the time.

Thanks,

Naboo

Answer 1

As @TheDarkKnight points out, cron has been deprecated in favor of launchd.

To use launchd, save the following as com.example.volume.plist in ~/Library/LaunchAgents/:

<?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>com.example.volume</string>         <key>ProgramArguments</key>         <array>                 <string>sh</string>                 <string>-c</string>                 <string>set volume 1.7</string>         </array>         <key>StartCalendarInterval</key>         <dict>                 <key>Hour</key>                 <integer>23</integer>                 <key>Minute</key>                 <integer>45</integer>         </dict> </dict> </plist> 

then run launchctl load ~/Library/LaunchAgents/com.example.volume to start. You can force the task to run immediately via launchctl start com.example.volume.

If you prefer to have it run as root, save to /Library/LaunchDaemons/ instead.

Answer 2

Please consider using the cron daemon. It is present in osx by default.

Create script for volume adjusting

#!/bin/bash -l /usr/bin/osascript -e "set Volume 1.7" 

Then add new line to crontab.

crontab -e 

By default, it will open in the vi(m) editor. But you can adjust the default editor with

export EDITOR=/path/to/your/awesome/editor 

Then add new string to crontab

0 20 * * * /path/to/volume/script.sh 

The given command will run every day at 8 pm.

Please find more crontab examples here: https://en.wikipedia.org/wiki/Cron