823 B
823 B
Crontab
Run programs at a given time. Useful for system cleanups and updates
crontab -e
Edit your crontab file
Syntax looks like (min, hour, day, month, year). Note these are absolute values,
so putting something like * 1 * * *
will run the program at 1:00am
every
day. To understand these times use this Example crontab
file:
PATH=/usr/local/bin:/bin:/usr/bin
HOME=/home/emiliko
* * * * * ~/program_1.sh # Every minute, on the minute
* * * * * (sleep 30; ~/program_1.sh) # Every minute at 30s in
1 * * * * ~/program_2.sh # Every hour at :01 minute
1 * 3 * * ~/program_3.sh # Every day at 3:01am
Since crontab doesn't support resolutions greater than 1 minute, a workaround
with sleep
can be used instead. program_1.sh
above effectively runs every
30s