Hi, I've been looking for a way to compare the current line in a loop to the previous line in the loop. I've been looking all day and can't seem to find an answer.

What I have so far: 

my $previous = '';
while (<>) {
  @gtf = split /\s+/, $_;
  chomp();

  if ("$gtf[9]" ne "$previous") {
    $gtf[2] =~ tr/ex*/ex1/;
  } else {
    $gtf[2]++;
  }
}

[download]

Basically, I want to compare item 9 of @gtf in the current iteration with item 9 of @gtf from the last iteration and if they are different, restart the ex counter at 1. $gtf[2] is "ex1" and increases by 1 every iteration. Thanks!

In reply to Comparing adjacent lines by daccame

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