Re: Pimp My RegEx

I'm trying to understand the rationale behind your regex. Don't you want something more like

my $parse_log_entry = qr/^($dateRegex.*?)(?=(?:^$dateRegex|\z))/ms;
[download]

? If so, then it I would process the file line-wise, and count only those lines that begin with your date pattern.

Or, if you need to do more than just counting, then something along the lines of

my $current;
while ( <DATA> ) {
  if ( /^$dateRegex/ ) {
    process( $current ) if defined $current;
    $current = $_;
  }
  else {
    $current .= $_;
  }
}
process( $current ) if defined $current;
[download]

Update: Added the more extended second alternative.

Update 2: Fixed bug (last line of code was missing).

the lowliest monk

Comment on Re: Pimp My RegEx Select or Download Code

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Re^2: Pimp My RegEx by heathen (Acolyte) on May 31, 2005 at 18:46 UTC
For the sake of brevity, I cut out my "payload" and just counted lines. I counted lines just to benchmark the regex times. My rationale was something like this: "find a line that starts with a date, capture all of the text (including new lines) until I can lookahead and find another date."	[reply]
Re^3: Pimp My RegEx by tlm (Prior) on May 31, 2005 at 18:57 UTC
Yes, but as originally written your regex would miss the last log entry, because it fails the positive lookahead assertion. Read more... (1081 Bytes) Regarding the payload, please see the update to my original reply. Update: Added further comments on the error in the original regex. the lowliest monk	[reply] [d/l] [select]
Re^4: Pimp My RegEx by heathen (Acolyte) on May 31, 2005 at 20:19 UTC
as originally written your regex would miss the last log entry, because it fails the positive lookahead assertion You are correct - definately an unintended consequence. Since a log file entry could span multiple lines I was using the lookahead to in effect say "stop capturing when you can see the next log file entry" The sample data I included in the original script probably should have included some of the more complex, multi-line log file entries.	[reply]