how to run crontab from php skript as a different user

[Frank R. Suchy]

Hi,

I want a php-script to maintain (some of) "my" cron jobs.

Therefore it has to modify some crontab.txt (no problem)
and has to execute crontab.

But since php runs as the apache-user it cannot run "my" crontab.

In general: Can a php-script run an external program under a different
user?

Thanx for any advise!
Frank

[Daniel Tryba]

Frank R. Suchy <us****@rem.o ve-sp.am.ardik.net > wrote:

Therefore it has to modify some crontab.txt (no problem)
and has to execute crontab.

But since php runs as the apache-user it cannot run "my" crontab.

In general: Can a php-script run an external program under a different
user?

Depends on your OS... on unix-like machines you might use sudo to do
this. But a more simple solution is to edit the crontab file from within
php and use the users cron to schedule reloads of the crontab file.

--

Daniel Tryba

[Frank R. Suchy]

Am Thu, 29 Jul 2004 23:49:36 +0000 (UTC) schrieb Daniel Tryba:

Frank R. Suchy <us****@rem.o ve-sp.am.ardik.net > wrote:

Therefore it has to modify some crontab.txt (no problem)
and has to execute crontab.

But since php runs as the apache-user it cannot run "my" crontab.

In general: Can a php-script run an external program under a different
user?
Depends on your OS... on unix-like machines you might use sudo to do
this.

Ehm, yepp, it's a Redhat Linux.
But I don't have root access or superuser privileges, so I can't use sudo.
I'm wondering whether there is some tool similar to sudo, which takes user
login and password in the commandline...
But a more simple solution is to edit the crontab file from within
php and use the users cron to schedule reloads of the crontab file.

That's exactly what I currently do. But I don't want to reload the file
e.g. every hour just because maybe once in a week there is another job to
be done. But when there is such a job to be added this should happen quite
quickly, reloading the crontab once a day or so would be too seldom...

Frank

[Daniel Tryba]

Frank R. Suchy <us****@rem.o ve-sp.am.ardik.net > wrote:

Depends on your OS... on unix-like machines you might use sudo to do
this.

Ehm, yepp, it's a Redhat Linux.
But I don't have root access or superuser privileges, so I can't use sudo.
I'm wondering whether there is some tool similar to sudo, which takes user
login and password in the commandline...

su propably can do the job, but not from the commandline... you'd have
to take a look a popen IMHO.

But a more simple solution is to edit the crontab file from within
php and use the users cron to schedule reloads of the crontab file.

That's exactly what I currently do. But I don't want to reload the file
e.g. every hour just because maybe once in a week there is another job to
be done. But when there is such a job to be added this should happen quite
quickly, reloading the crontab once a day or so would be too seldom...

Have a job that looks for a special file every minute, if file exists
reload the crontab file and than remove special file. If crontab file
gets edited, touch the special file and within a minute the crontab
will be reloaded. Overhead is limited to a file exists test...

--

Daniel Tryba