this is a common problem with perl scripts, the user that calls the script (via some automated process) is not the user that needs to RUN the script.

How to do this?

its called a setuid perl script, and basically what happens is that the the script has the ablility to change its user privileges on the fly.

There are a great many possible problems where setuid perl scripts can create security concerns, but there are corner cases where there just isnt any other way to do it.

The most common approach is that the root user must run the script no matter what user started the script.

look for the setuid perl package for your distro

on redhat and friends its called perl-suidperl

install this package, and then you need to do the following:

(WARNING - if you arent careful and dont pay attention, you can royally screw up your system, practice this in a lab setting first)

find the script you want to run and apply the setuid bit to it

first chown the file to the user that needs to run the script, then apply the setuid bit

if you have mc installed use that tool, its graphical enough its clear what you need to do.

if you dont, chmod +s /path/to/script should work

do a

ls -l /path/to/script

and the permissions part of the output should look something like this:

-rwsr-sr-x

thats chmod 755 plus the setuid bit

now when you run the perl script it will run with the permsissions of the owner of the script.

depending on what your script actually does, this may be all you need to do.

but if you script has to make system calls, or call other scripts, they might not execute with the permsissions you think they should.

a perl script will know that it has been called as a setuid script and it will actually carry with it TWO sets of permissions the user who called the script, and the user that is the setuid user.  Perl calls them the real user and the effective user.

if you have to ( and only if you have to, meaning run a test and see if you get the results you want first) add the code snippet below to the top of your script before your script does anything:

<begin code>
# set real userid to effective userid since this is a suidperl script
$< = $> ;
<end code>





Almost done....

you will also possibly need to edit the script itself to add a single command at the top

never mind the last two lines of my above post, I pasted in the wrong place.  sorry about that.