Question

I have an already setted up cron job. Now i have a file whose cron i have to setup such that my file should run at 9:00 am,11:00am,1:00pm,5:00pm and 7:00pm

Idont have much idea about cron So can anyone please help me in setting up this cron for my file at the aboove given timings !!

Answer 1

The format for the CRON Jobs is:

minute hour dom month dow user cmd

---

minute This controls what minute of the hour the command will run on,
and is between ‘0’ and ’59’

---

hour This controls what hour the command will run on, and is specified in
the 24 hour clock, values must be between 0 and 23 (0 is midnight)

---

dom This is the Day of Month, that you want the command run on, e.g. to
run a command on the 19th of each month, the dom would be 19.

---

month This is the month a specified command will run on, it may be specified
numerically (0-12), or as the name of the month (e.g. May)

---

dow This is the Day of Week that you want a command to be run on, it can
also be numeric (0-7) or as the name of the day (e.g. sun).

---

user This is the user who runs the command.

---

cmd This is the command that you want run. This field may contain
multiple words or spaces.

---

If you don’t wish to specify a value for a field, just place a * in the
field.

---

Here is an example of how a crontab is setup.

01 * * * * root echo "This command is run at one min past every hour"
17 8 * * * root echo "This command is run daily at 8:17 am"
17 20 * * * root echo "This command is run daily at 8:17 pm"
00 4 * * 0 root echo "This command is run at 4 am every Sunday"
* 4 * * Sun root echo "So is this"
42 4 1 * * root echo "This command is run 4:42 am every 1st of the month"
01 * 19 07 * root echo "This command is run hourly on the 19th of July"