Menu
I'm trying to get familiar with cron jobs, and I think I get the basic idea (scheduling, syntax, etc), But, I can't seem to get it right on my mac with Terminal - where exactly do I find the Crontab? How should I reference the paths to scripts?
What I'm trying to do is hit a php script on a remote machine (http://...) - Is that possible at all?
839
Although launchd is the preferred method in macOS, the cron method still works in macOS as well. cron is a Linux utility that schedules a command or script on your server/computer to run automatically at a specified time and date. A cron job is the scheduled task and it is very useful to automate repetitive tasks.
To see your active cron jobs, you can use the crontab -l command. If you want to, for instance, run a Python script using a cron job, you'll have to deal with some added complexity. The way you should set this up is by having two scripts — the Python script and an executable shell script that runs the Python script.
The cron reads the crontab (cron tables) for running predefined scripts. By using a specific syntax, you can configure a cron job to schedule scripts or other commands to run automatically.
Type crontab -e to edit your cron table and crontab -l to list the current contents.. Type man 1 crontab for more info on that command and man 5 crontab for more info on the cron table file format.
For example, to download the stackoverflow page every day at 10:00a, run crontab -e, enter this line, and then save/quit. The output will be written to a file in your home directory.
0 10 * * * /usr/bin/curl -s http://stackoverflow.com > ~/stackoverflow.html
To get started with launchd (instead of cron) you'll want to first create an empty .plist file, for example local.mytask.plist and put it somewhere. ~/Library/LaunchAgents is probably a good place. Open that in text editor and copy in the code below
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//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>local.mytask</string>
<key>ProgramArguments</key>
<array>
<string>/opt/local/bin/wget</string>
<string>http://someserver/somepage.php</string>
</array>
<key>StartInterval</key>
<integer>300</integer>
<key>RunAtLoad</key>
<true />
<key>StandardErrorPath</key>
<string>/dev/null</string>
<key>StandardOutPath</key>
<string>/dev/null</string>
</dict>
</plist>
Then "activate" the file from the command line:
sudo launchctl load /Users/my_username/Library/LaunchAgents/local.mytask.plist
To make it load automatically, create a ~/.launchd.conf file with the same line (minus sudo launch)
load /Users/my_username/Library/LaunchAgents/local.mytask.plist
The above instructions above have been copied from www.davidlanier.com and reposted here for your reference.
37
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
