If your file is not huge, you can store the lines in an array instead of a temp file (UNTESTED): 
#!/usr/bin/perl
use strict;
use warnings;

my $file = "c:\\tmp.txt";
open( my $fh, "<", $file ) or die $!;

my @array;
foreach (<$fh>) {
    chomp;
    if ( $_ =~ m/^\s+\d/ ) {
        $_ =~ s/^\s+//g;
        $_ =~ s/\s+$//g;
        $_ =~ s/\s+/,/g;
        push @array, "$_  \n";
    }
}

my $OUTNET2 = "c:\\final.txt";
open my $out, '>', $OUTNET2 or die $!;
my %hash;
for (@array) {
    my $key = join ',', ( split /,/ )[ 1, 2, 3, 4 ];
    print $out $_ unless $hash{$key}++;
}
close $out;

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Note that I used your @array, which you didn't seem to be using.

In reply to Re: Perl script run foreach loop and sort without having to save and reopen the filehandle each time. by toolic
in thread Perl script run foreach loop and sort without having to save and reopen the filehandle each time. by john.tm

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