crontab
Cron is a time-based scheduling service in Linux / Unix-like computer operating systems.
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1 crontab -e # edit cron for current user
2 crontab -l # list cron for current user
3
Every ten minutes
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1 */10 * * * * /path/to/command
Every hour
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1 0 * * * * /path/to/command
Every 2 hours
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1 0 */2 * * * /path/to/command
Once a day at midnight
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1 0 0 * * * /path/to/command
Once a day at eight am
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1 0 8 * * * /path/to/command
Annotations
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1 # Order of crontab fields
2 # minute hour mday month wday command
3
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1 string meaning
2 ------ -------
3 @reboot Run once, at startup.
4 @yearly Run once a year, "0 0 1 1 *".
5 @annually (same as @yearly)
6 @monthly Run once a month, "0 0 1 * *".
7 @weekly Run once a week, "0 0 * * 0".
8 @daily Run once a day, "0 0 * * *".
9 @midnight (same as @daily)
10 @hourly Run once an hour, "0 * * * *".