Re: Re: grab only if pattern matches previous line

Hi, I should probably clarify a couple things. 1. the data file is large. 2. there is a lot of useless header information and data I want to skip (some of it messy). 3. It is true that for each case where there is a request(REQUEST_NAME the very next line will always be the START_TIME, so really just incrementing one line past the good requests would work (though it's probably not as safe). 4. the BADSTRING is not the entire string. Thanks!

Comment on Re: Re: grab only if pattern matches previous line

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Re: Re: Re: grab only if pattern matches previous line by greenFox (Vicar) on Jul 11, 2003 at 02:36 UTC
If your data file is really large then you should work on the data as you slurp it. I used an array because that is what your sample code used :) `while(<FILE>){ next if /^matches messy header/; chomp; if (/matches some string/){ my $next_line = <FILE>; # do something to $next_line here print "$_, $next_line\n"; } }` [download] -- Do not seek to follow in the footsteps of the wise. Seek what they sought. -Basho	[reply] [d/l]

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Re: Re: Re: grab only if pattern matches previous line
by greenFox (Vicar) on Jul 11, 2003 at 02:36 UTC

If your data file is really large then you should work on the data as you slurp it. I used an array because that is what your sample code used :)

while(<FILE>){
  next if /^matches messy header/;
  chomp;
  if (/matches some string/){
    my $next_line = <FILE>;
    # do something to $next_line here
    print "$_, $next_line\n";
  }
}
[download]

--
Do not seek to follow in the footsteps of the wise. Seek what they sought. -Basho

[reply]
[d/l]