Crontab

crontab -> allows to schedule the execution of scripts
-l      -> show crontab list
-e      -> edit the crontab table. With this more scripts can be added

0   16  *   *   *    $Home/src/cronjobs/daily.sh
0   *   *   *   *    $Home/src/cronjobs/hourly.sh
*   *   *   *   *    $Home/src/cronjobs/minutely.sh

Columns:

1. minute 0-59

2. hour 0-23

3. day month 1-31

4. moth 1-12

5. day week: 0-7 (0 & 7 sunday)

6. script/command

Example 1 (for the minute column)

1       -> runs in minute 1  
1,10,18 -> runs at minute 1, 10 and 18  
`*/5    -> runs every 5 minutes  
1-10    -> runs the first 10 minutes of every hour  
*       -> runs every minute

Example 2

*/15 4 * * * script.sh

Run script.sh:

• every day of the week

• every month

• every day of the month

• at 4 am

• every 15 minutes

Example 3

0 3 * * 1 script.sh

Run script.sh:

• only if it's monday

• every month

• every day of the month

• at 3 am

• at minute zero

Note: when editing the crontab table, make sure the columns are sorted