#!/usr/bin/perl -ws

use strict;

open my $fh, '<', 'file.txt' or die $!;

my @lines = (
    "this is line 1; foo \n",
    "this is line 2: bar \n",
    "this is line 3: foobar \n",
);

print "PRINTING FROM FH\n";
working_routine($fh);

print "\n\nPRINTING FROM ARRAY\n";
working_routine(\@lines);


sub create_iter {
    my $arg = shift;
    if (ref $arg eq 'GLOB') {
        return <$arg>;
    }
    elsif (ref $arg eq 'ARRAY') {
        return shift @$arg;
    }
    else { die "Unknown type\n"}
}

sub working_routine{
	my ($data) = @_;
	my $flag = 0;
	while(my $line = create_iter($data)){
		if($line =~ /matches something/){
			next;
		}
		elsif($line =~ /matches something else/ and ! $flag){
			create_iter($data);
			my $newline = create_iter($data);
			dosomethingto($newline);
		}
		elsif($line =~ /gotcha/ && $flag){
			morework($line);
		}
		else{
			next;
		}
	}
}