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Re: need help editing lines of a file
by davorg (Chancellor) on Dec 18, 2001 at 19:39 UTC

    What was wrong with the answers that you got the last time you asked this question?

    Oh, and learn to choose better subject lines.

    Originally posted as a Categorized Answer.

[reply]
Re: need help editing lines of a file
by dragonchild (Archbishop) on Dec 18, 2001 at 19:43 UTC
    If I understand you correctly, you want
    • Step through a text file line by line
    • If you come across a line with a certain set of characteristics ...
    • Then you want to do something to the line just prior
    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]
    }
}

    [download]
    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.

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