Perl logging what scripts/modules accesses another module - perl

Question

We maintain a huge number of perl modules, actualy its so huge that we don't even know of all modules that we are responsible for. We would like to track what scripts and modules accesses another module in some sort of log, preferably stored by module name, so that we can evaluate whether its a risk to update a module and so that we can know what we might affect.
Is there any simple way to do this?

Answer 1

You could do a simple regex search:
use strict;
use warnings;
my %modules;
foreach my $perl_file (#file_list) {
open FILE, $perl_file or die "Can't open $perl_file ($!)";
while (<FILE>) {
if (/\s*(?:use|require)\s*([^;]+);/) {
$modules{$1}{$perl_file}++;
}
}
}
This is quick and dirty, but it should work pretty well. You end up with a hash of modules, each of which points to a hash of the files that use it.
Of course, it will catch things like use strict; but those will be easy enough to ignore.
If you have things like use Module qw/function/; You will grab the whole thing before the semicolon, but it shouldn't be a big deal. You can just search the keys for your known module names.
A downside is that it doesn't track dependencies. If you need that information you could add it by getting it from cpan or something.
Update: If you want to log this at runtime, you could create a wrapper script and have your perl command point to the wrapper on your system. Then make the wrapper something like this:
use strict;
use warnings;
use Module::Loaded;
my $script = shift #ARGV;
#run program
do $script;
#is_loaded() gets the path of these modules if they are loaded.
print is_loaded('Some::Module');
print is_loaded('Another::Module');
You might run the risk of funny side effects, though, since the method of calling your script has changed. It depends on what you are doing.

Answer 2

Maybe edit sitecustomize.pl so that each time when Perl runs, it would write some info in a log, and then analyse it? Add something like this to sitecustomize.pl:
open (LOG, '>>',"absolutepathto/logfile.txt");
print LOG $0,"\t",$$,"\t",scalar(localtime),"\n";
open SELF, $0;
while (<SELF>) {
print LOG $_ if (/use|require/);
}
close SELF;
print LOG "_" x 80,"\n";
close LOG;
EDIT:
Also, we forgot about %INC hash, so the code above may be rewritten as follows, to include more data about which modules were actually loaded + include files required by do function:
open (LOG, '>>',"absolutepathto/logfile.txt");
print LOG $0,' ',$$,' ',scalar(localtime),"\n";
open SELF, $0;
while (<SELF>) {
print LOG $_ if (/use|require/);
}
close SELF;
END {
local $" = "\n";
print LOG "Files loaded by use, eval, or do functions at the end of this program run:\n";
print LOG "#{[values %INC]}","\n";
print LOG "_" x 80,"\n";
close LOG;
}