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If there is an entry in crontab with the following syntax:

* * * * * /usr/bin/program

How often would this be run? How would it initially get launched?

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Also see – John Gardeniers Oct 1 '10 at 1:39
up vote 3 down vote accepted

Your cron entry will execute every single minute of every hour of every single day of every single month of every single year

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A search for crontab syntax will give you man indepth explanations.

I find it handy to note the ordering in a comment at the top as a reminder.

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Or you can just do man 5 crontab. – Dennis Williamson Oct 1 '10 at 1:31
@Dennis, do you really think most of us would remember what number to use in a man command? If we could remember that much we probably wouldn't need to keep using man. – John Gardeniers Oct 1 '10 at 1:41
@John: man crontab, scroll to the bottom, see See Also "crontab(5)", man man the sections are listed on the second (25-line) screenful. "5 File formats and conventions". My comment was not intended as an "oh should already know this", but as "here's some useful information". – Dennis Williamson Oct 1 '10 at 1:46
@Dennis, I've never noticed that in a man file, probably because I only look for specific information. I'll try to keep it in mind. Thanks. – John Gardeniers Oct 1 '10 at 2:00
Just man crontab will do. The crontab manpage is not always in section 5. I'm typing this from Slackware Linux 13.1 and it's in section 1 here. – halp Oct 1 '10 at 4:55

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