use strict;
use warnings;

open (my $fh, '<', '/usr/share/dict/words') or die "Unable to open words: $!";

while (1) {

    my $line = <$fh>;
    if ( $line =~ /^M....$/) {
        my $pos = tell($fh) - length($line);
        chomp $line;
        print "$line found\n";

        # Go back to beginning of file (rewind)
        seek ($fh,0,0);

        # Now go and read that record again
        seek ($fh, $pos, 0);
        $line = <$fh>;
        chomp $line;
        print "$line found again!\n";
        last;
    }
}

close ($fh);