I have inherited about 900 perl and shell scripts. A lot of code was cut/pasted over the last 5 years and my boss has asked me to try and clean things up.

One issue is this: 

use Getopt::Long;
use Net::SSH qw(sshopen2);
use Net::Ping;
use Net::FTP;
...

[download]
This script DOES use sshopen2, but not Ping or FTP.

What could I do (from another perl script scanning through *.pl files) to report that this file includes but does not use Ping or FTP?

I have tried using >perl -MO=Xref,-d test.pl to generate a cross-reference list of variables, but this does not identify packages that are included, but not used.

I thought about taking test.pl and creating copies like "a.pl", "b.pl", "c.pl", "d.pl".. with the difference:

a.pl - comments out the "use Getopt::Long" line

b.pl - comments out the "use Net::SSH qw(sshopen2)" line ..

Then doing a perl -c on each copy to see if I could identify useless "use" statements if things tested correctly. But this does not catch things.

I tried using

perl -MO=Deparse test.pl
Hoping that this would expand:

&sshopen2() into

&NET::SSH::sshopen2()

And I could grep the expanded output to find the packages that ARE used and do my own bookeeping, but Deparse does not fully-qualify function calls.

So I am kind of stumpped. Any thoughts?

In reply to How do I detect what modules are not being used? by FatDog

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