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Editing the cronjobs

Frequent Advisor

Editing the cronjobs

Hello Everyone,


Can anyone please tell me how can I make some entries in cron if I have to make some process automated.


Like I want that the nickel script should run daily or on weekly basis and a script containing some imp commands like


ioscan, bdf. cmviewcl, etc should run daily in the morning and evening.


Please suggest how can I do it and where I have to edit.


I don't want ready made script as I have to learn how to do it I want the procedure or anything related to it in a basic form.


Since I am new to hpux I want to know about unix.


Please also guide me in any way possible.




Honored Contributor

Re: Editing the cronjobs

To edit a crontab file you use 'crontab -e'.  This will open your crontab file in the 'vi' editor.


From there you add entrires in the following format:


<min> <hr> <monthday> <month> <day of week> <command to run>


The explanation of each field from the 'crontab' man page (remember that man pages are your friend):


      The entries in a crontab file are lines of six fields each.  The
      fields are separated by spaces or tabs.  The lines have the following

           minute  hour  monthday  month  weekday  command

      The first five are integer patterns that specify when the sixth field,
      command, should be executed.  They can have the following ranges of

           minute         The minute of the hour, 0-59

           hour           The hour of the day, 0-23

           monthday       The day of the month, 1-31

           month          The month of the year, 1-12

           weekday        The day of the week, 0-6, 0=Sunday

      Each pattern can be either an asterisk (*), meaning all legal values,
      or a list of elements separated by commas.  An element is either a
      number in the ranges shown above, or two numbers in the range
      separated by a hyphen (meaning an inclusive range).  Note that the
      specification of days can be made in two fields: monthday and weekday.
      If both are specified in an entry, they are cumulative.  


For example, if you want to run a script called "dosomething" that is in the /do/it/now directory at 3:15 AM every Wednesday morning you crontab would like like:


15 3 * * 3 /do/it/now/dosomething


Read through the crontab man page for more explanations.


# man crontab