For security reasons, modern unices disable SUID bit on scripts.
(Beccause it's often IMPOSSIBLE to have safe SUID shell script)
suidperl allow you to use this suid feature even on such system...
For a detailed explanation see :
perlsec...
Another (more general) safe way is the prog
sudo
"
Only
Bad
Coders
Code
Badly
In
Perl" (OBC2BIP)