As far as I know it, there's no easy way of doing this from within perl. Once the script is launched, you can't change it's 'owner' from inside the script. However, in many cases when I had to deal with a similar problem, I found 'sudo' shell command rather useful.

(from the man page) The command..

allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file.

So, if I wanted to run your script as user 'nobody', I'll simply go: 
home:vlad> sudo -u nobody myscript

[download]


UPDATE: as an afterthought, I guess you could try crafting a perl wrapper script that'll do nothing but execute a system command like so: "su nobody; $command". But, again, that could be as easily accomplished outside of Perl.

_____________________ 
$"=q;grep;;$,=q"grep";for(`find . -name ".saves*~"`){s;$/;;;/(.*-(\d+)
+-.*)$/;
$_=["ps -e -o pid | "," $2 | "," -v "," "];`@$_`?{print"+ $1"}:{print"
+- $1"}&&`rm $1`;
print$\;}

[download]

In reply to Re: forcing script to run as specific user by vladb
in thread forcing script to run as specific user by c

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