Shell Programming and Scripting

#!/usr/bin/perl -w
use strict;
use warnings;

my $file = "file_a";
my @line = ();
my $index = 0;
my %ind_file = ();

open(FILE, $file) or die($!);
while(<FILE>) {
chomp($_);
 if ($_ eq '')
 {
  print "undefined line \n";
 }
 else
 {
  my ($name, $value) = split(' ', $_);

# Put the key => value pair in the hash
  $ind_file{$name} = $value;
 # print "$name => $value \n";
 my ($k, $v) = each %ind_file;
 print "$k => $v \n";
 }
}
close(FILE);

while ( ($k, $v) = each %ind_file) {
 print "Post $k => $v \n";
}
========================================================

HOSTNAME aria
AVAIL_MEM 21
USED_MEM 11
HOSTNAME borneo
AVAIL_MEM 31
USED_MEM 1
HOSTNAME croc
AVAIL_MEM 11
USED_MEM 21
USER bob
JL/U 2
RUN 3
PEND 4
WAIT 1
USER jill
JL/U 3
RUN 2
PEND 10
WAIT 3
QUEUE short
JOBS 10
PEND 3
RUN 1
QUEUE long
JOBS 2
PEND 10
RUN 2
=====================================

while(my $line = <FILE>) {
        chomp $line;
        if ($line){
                if ($line =~ m/HOSTNAME\ (.*)/){
                        $hostname = $1;
                }
                else {
                        my ($k,$v) = split(" ",$line);
                        $hash{$hostname}{$k} = $v;
                }
        }
}
foreach my $host(sort keys %hash){
        print "$host \n";
        print "$_\t$hash{$host}{$_}\n" foreach (keys %{$hash{$host}});
        print "-"x80,"\n";
}

open my $fh, '<', "$filename" || die "couldnot open the filename $!";