#!/usr/bin/perl 
use warnings;
use strict;
use Data::Dumper;

my $serverPort = 12345;

my @ActivePorts = `netstat -a | grep $serverPort`;

# Strip white spaces
@ActivePorts = map { s/^\s+|\s+$//g; $_; } @ActivePorts;

print Dumper \@ActivePorts;

__END__

$VAR1 = [
          'udp        0      0 localhost:12345         *:*'
        ];

##</code><code>##

#!/usr/bin/perl 
use warnings;
use strict;
use Data::Dumper;

my $serverPort = 12345;

my @ActivePorts = `ss -lp | grep 12345`;

# Strip white spaces
@ActivePorts = map { s/^\s+|\s+$//g; $_; } @ActivePorts;

print Dumper \@ActivePorts;

__END__

$VAR1 = [
          'tcp    UNCONN     0      0            127.0.0.1:ipproto-12345               *:*        users:(("perl",8179,3))'
        ];