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I have a basic understanding of cron jobs, but I came across a tutorial today which recommends adding:

30 3 * * * wget
31 3 * * * rm -rf recur

What does the rm -rf recur do?

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up vote 8 down vote accepted

It compensates for someone who doesn't know about the -O option for wget -- specifically, wget -O /dev/null.

More specifically, the wget call in that crontab hits a URL (presumably to trigger some sort of server-side processing -- always a sign of an absolute idiot of a web application or hosting environment). Since wget downloads files, it will store the downloaded file named recur it in the current directory. Then, a minute later, another cronjob deletes the file that was created, for tidiness.

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Actually I believe -O to be the incorrect option... Would be -o instead – Jeremy Bouse Aug 25 '11 at 1:26
@Jeremy Bouse: No; -O places the document contents somewhere, -o places the wget console output somewhere. Using -o /dev/null in scripts is possible (although -q is better), and -o /some/log/file is often useful, but is unrelated to the question. – womble Aug 25 '11 at 1:46

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