# Main script (.pl file)

use strict;
use warnings;
use Capture::Tiny 'capture_stderr';
use MyMod;

my $warnings1 = capture_stderr
{
    MyMod::run_warnings();
};

print "\nCaptured the following warnings:\n$warnings1" if $warnings1;

my $warnings2 = capture_stderr
{
    MyMod::run_no_warnings();
};

print "\nCaptured the following warnings:\n$warnings2" if $warnings2;

######################################################################
+#########
# Test module (.pm file)

package MyMod;

use strict;
use warnings;

sub run_warnings
{
    print "\nBeginning MyMod::run_warnings()\n";
    warn  'This is your first warning!';
    warn  'This is your second warning!';
    warn  'This is your last warning!';
    print "Leaving MyMod::run_warnings()\n";
}

sub run_no_warnings
{
    print "\nMyMod::run_no_warnings ... done\n";
}

1;
[download]

Output:

 1:56 >perl 940_SoPW.pl

Beginning MyMod::run_warnings()
Leaving MyMod::run_warnings()

Captured the following warnings:
This is your first warning! at MyMod.pm line 9.
This is your second warning! at MyMod.pm line 10.
This is your last warning! at MyMod.pm line 11.

MyMod::run_no_warnings ... done

 1:56 >
[download]