If I understand you correctly, you want You have a number of options. The easiest to implement is to read the file into an array, then manipulate it. Something like this: 
my @lines = <>;
foreach my $index (0 .. $#lines) {
    if ($lines[$index] =~ /word/) {
        # Do what you want here, but to $lines[$index - 1]
    }
}

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The only problem with that method is if your text file is over 50% of your available RAM. Then, instead of being blazingly fast, it's only moderately fast.

Originally posted as a Categorized Answer.

In reply to Re: need help editing lines of a file by dragonchild
in thread need help editing lines of a file by polr

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