999Running Repetitive Jobs on OSX
Traditionally Unix systems use crontab to schedule and run repetitive jobs, OSX uses launchd, an init and operating system service management daemon.
Here is a script that call my index.php every 120 seconds. (I am download snow webcams in the index.php.)
<?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>org.trembl.snow</string> <key>ServiceDescription</key> <string>Getting Snow Pictures</string> <key>ProgramArguments</key> <array> <string>/Applications/XAMPP/bin/php</string> <string>/Applications/XAMPP/xamppfiles/htdocs/snow/index.php</string> </array> <key>RunAtLoad</key> <true/> <key>StartInterval</key> <integer>120</integer> </dict> </plist>
In Xcode, the same script looks like this:
I made a couple of errors, trying to get the script to run.
sudo chown <user>:staff org.trembl.snow.plist
Incorrect permissions also cause the
Load failed: 122: Path had bad ownership/permissions
The name of the file and the Label need to match. org.trembl.snow and org.trembl.snow.plist
The plist need to be placed into ~/Library/LaunchAgents.
If your Program has arguments, they need to be specified in an array:
<key>ProgramArguments</key> <array> <string>/Applications/XAMPP/bin/php</string> <string>/Applications/XAMPP/xamppfiles/htdocs/snow/index.php</string> </array>
Both strings need to be absolute. I got this error:
Load failed: 122: Path had bad ownership/permissions, which was caused by only saying
index.phpinstead of the whole absolute path.
launchctl bootstrapand not the obsolete
sudo launchctl bootstrap gui/`id -u` ~/Library/LaunchAgents/org.trembl.snow.plist
sudo launchctl bootout gui/`id -u` ~/Library/LaunchAgents/org.trembl.snow.plist