thanks !!! these two comments gave me the answer !!!
( or even different versions of the same operating system && Any halfway secure operating system won't let you )
the script won't work on Slackware, but runs fine on Mandrake Linux ( the target system is RedHat, so another test is needed, but i'm confident it's not "halfway secure" as Slack )
again, thank you !!!!

In reply to Re^2: (perlvar) changing program name by slipwalker
in thread (perlvar) changing program name by slipwalker

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