use strict;

die "Usage: <file1> <file2>\n" unless @ARGV == 2;

my $file_1 = $ARGV[0];
my $file_2 = $ARGV[1];

open (FILE2, $file_2) or die "Couldn't open file: $!";
while (<FILE2>) {
    if ($_ =~ s/^confederation-as-router\:\W+\d\W+\d+\W//) {
        push(my @file2, $_);

#I can print the entire array here.

open (FILE3, '>routers') or die "Couldn't open file: $!";
        print FILE3 @file2;
        close FILE3;