Shell Programming and Scripting

#! /usr/bin/perl
use warnings;
use strict;
 
(@ARGV != 3) && die "Enter co-ordinates. Exiting ";
 
my ($x, $y, $z) = @ARGV;
my (@nos, @near_node);
my ($dist, $near_dist);
 
open (COORD, "input");
while (<COORD>) {
    chomp;
    if (/^\*NODE/ .. /^\*\*/) {
        if (/^\*NODE/) { next }
        if (/^\*\*/)   { last }
 
        @nos = split /\s+/;
        @nos = map { s/[.,]+$//; $_ } @nos;
        $dist = sqrt ((($x - $nos&#91;2]) ** 2) + (($y - $nos[3]) ** 2) + (($z - $nos[4]) ** 2));
 
        #print "$dist .. @nos\n"; # Uncomment this line if you want to see dist of each node from input and the node itself.
        if (!defined($near_dist)) {
            $near_dist = $dist;
            @near_node = @nos;
        }
        elsif ($dist <= $near_dist) {
            $near_dist = $dist;
            @near_node = @nos;
        }
    }
}
close (COORD);
print "Nearest node: @near_node\nDistance: $near_dist\n";