I have the following code - which strings together nmap, fuser, and ps and gives me pretty output. The problem I have is that some subscripts of @pid array contain a list instead of a scalar so when it prints I get strangely formatted output. 
use strict;

# Variables

my @nmap;
my @port;
my @protocol;
my @pid;
my @app;
my $junk;
my $i;
print "\nScanning for open ports... ";
chomp(@nmap = `nmap localhost`);
for (1..5) {
    shift(@nmap);
}
for (1..2) {
    pop(@nmap);
}
$i = 0;
foreach (@nmap) {
        if (! @nmap[$i] =~ /^\s*$/) {
                (@port[$i], @protocol[$i]) = split /\//, $_;
                @protocol[$i] = split / /, @protocol[$i];
                @pid[$i] = `fuser -n @protocol[$i] @port[$i]`;
                chomp(($junk, @pid[$i]) = split /:\s+/,@pid[$i]);
                @app[$i] = `/bin/ps --no-headers -o %c @pid[$i]`;
                $i++;
        }
}
print "done.\n\n";
print "The following ports are open on your system\n\n";
printf "%8s%12s%12s%15s\n","Port", "Protocol", "PID", "App";
print "-----------------------------------------------\n";

$i = 0;
foreach (@nmap) {
    printf "%8s%12s%12s%16s\n", @port[$i], @protocol[$i], @pid[$i][1],
+ @app[$i];
    $i++;
}

[download]
good looking output where there is only one PID per port: 
Scanning for open ports... done.

The following ports are open on your system

    Port    Protocol         PID            App
-----------------------------------------------
      22         tcp       21232           sshd

     515         tcp       21943            lpd

    6000         tcp        1738              X

[download]
bad looking output with multiple PIDs per port: 
Scanning for open ports... done.

The following ports are open on your system

    Port    Protocol         PID            App
-----------------------------------------------
      25         tcp         198           exim

      53         tcp         226          named

     139         tcp242  3995  3997  4007  4009  4011           smbd

     143         tcp   269  1006         xinetd

[download]
I think I know what I want to do but I don't know how to do it. I want to print the first item in the @pid$i list and then have a foreach loop to print the rest after the first line.

In reply to @pid = a list - need a way to print by Hayl_

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