cron job 1

[spookie]

hi all
can someone give me the information about cron job in PHP,
what they do?how it is done etc?

spookie

 

[vcherubini]

Well, PHP is not the language that does the cron job. There is a program on Linux machines called cron. There is also a similar program on Windows machine, but I do not know what its called.

PHP can execute that program by using the exec() function.

You can check out

http://www.php.net/manual/function.exec.php

to see how its done.

Hope this helps.

-Vic

vic cherubini
krs-one@cnunited.com

http://www.cnunited.com

====
Knows: Perl, HTML, JavScript, C/C++, PHP, Flash
====

 

[spookie]

thnaks cherubini
i know the function of exec() but the question is what exactly the cron does?
as far as i know it does a particular task on regular basis
but can u tell me how to set up a cron job?
say i want to send email every day on some specific time.can it be done thru cron?

thank you in advance

spookie

 

[vcherubini]

Oh. That I do not know how to do.

You might go to one of the Linux forums and ask there.

Sorry, I am no Linux guy.

-Vic vic cherubini
krs-one@cnunited.com

http://www.cnunited.com

====
Knows: Perl, HTML, JavScript, C/C++, PHP, Flash
====

 

[SM777]

crontab is indeed a scheduler to run jobs at certain times. Sure, check the linux forum. Also searching on

http://www you

should find quick easy guides such as:

http://www.superscripts.com/tutorial/crontab.html

http://howto.lansystems.com/index.php?howto=crontab_guide

http://hoth.stsci.edu/man/man1/crontab.html

I find that the .edu college sites offer the best advice.

Basically, you can enter

->crontab -l to list your jobs
->crontab -r to remove them
->crontab -e to edit them

while your testing the best way I found was to create a file with pico called say cronjobs then issue a

->crontab cronjobs

cronjobs will look something like:

0 0 * * 0 /home/users/bofh/zaplogfiles

which runs a zaplogfiles batch on midnight every sunday.

Other considerations:

you have to leave a blank line after your last crontab entry else it wont work (dont know if true)

crontab will only start the job when it reaches the time - it won't backdate jobs if you submit them a few minutes after the scheduled time.

I dont know wether the jobs are triggered with reference to your hardware clock or you software clock - if things arent running on time then see if you can find a clocksync utility.

 

[spookie]

thanks SM777
it certainly added to my info