Shell Programming and Scripting

so i have scripts that get run in ways similar to this:

Code:

cat script.pl | perl - $1 $2 $3

cat script.rb | ruby - $1 $ 2 $3

my question is, how can i verify that that the "perl" or "ruby" or "python" tool being run on the box is actually a legit tool? meaning, someone may move the tool from where it is originally supposed to be i.e. /usr/bin and may move it somewhere else. and then put a counterfeit version back in its place in /usr/bin.

is there any testing i can do on the tools themselves that will confirm yes, this tool is valid and is not something unusual?

my first thought was to use the file command...like this:

Code:

fie /usr/bin/python
file /usr/bin/perl

but im afraid there may be ways to fool this or tinker around with this to give inaccurate information masquerading as true.

any ideas?

Keep a checksum like

Code:

sh256sum /usr/bin/perl

and compare before running.

Hi.

Brief explanation and pointers to several specific programs:
File integrity monitoring - Wikipedia, the free encyclopedia

Some search results:

185K hits:
file integrity monitoring linux - Google Search

400+ hits:
file integrity monitoring free download - SourceForge

Best wishes ... cheers, drl