Cron jobs

i am new for cronjobs

can someone please tell me what logic is behind these RED Numbers and stars below?

--> crontab -l
00 1 * * * /home/scripts/TarprodContent > /tmp/MprodBkup.log 2>&1
00 1 * * * /home/scripts/TarTprodContent > /tmp/TprodBkup.log 2>&1
00 1 * * * /home/scripts/TarTdprodContent > /tmp/TdprodBkup.log 2>&1
00 1 * * * /home/scripts/TTprodContent > /tmp/TTprodBkup.log 2>&1
00 1 * * * /home/scripts/TDprodContent > /tmp/DprodBkup.log 2>&1
00 1 * * * /home/scripts/TSprodContent > /tmp/SprodBkup.log 2>&1
0,15,30,45 5-22 * * * /home/scripts/VerifyDocbasesUp > /tmp/check_docbase_connectivity 2>&1

thanks in advance

'man crontab' should be a good starting point!

The red numbers and * tell cron when to run your job. It is broken up like this.

# +---------------- minute (0 - 59)
# | +------------- hour (0 - 23)
# | | +---------- day of month (1 - 31)
# | | | +------- month (1 - 12)
# | | | | +---- day of week (0 - 7) (Sunday=0 or 7)
# | | | | |

• • • • • command to be executed

so the first command is the minute the second is hour, day of month, month, day of week.

A * means run at every time increments. Therefore if they are all *'s the cronjob would run every minute of every hour of every day of every month of every day of year.

Add cronjobs by using crontab -e and view cronjobs by using crontab -l.

example

0 12 * * * /tmp/buffer/script.sh

this would run at noon of every day of every month of every day of week.

thanks for your quick reply

Very nicely done.. explains it in really simple format which i believe everyone should be able to follow

Thanks

oh yes...thats right. its nicely described.

thanks again