Re: Regex to select multiple lines

Ok, some heavy assumptions in the following code, but oh well. Here goes:

#! /usr/bin/perl
use strict;

# Assume a blank line to mean no whitespace
$/ = "\n\n";

foreach my $record ( <DATA> ) {
  chomp( $record );

  my @data = split( "\n", $record );

  # Take the last element of the last three lines in the record
  my $txname = ( split( / /, $data[ -3 ] ) )[-1];
  my $txtime = ( split( / /, $data[ -2 ] ) )[-1];
  my $errorcode = ( split( / /, $data[ -1 ] ) )[-1];

  print "$txname\t\t\t$txtime\t\t$errorcode\n";
}


__DATA__
Message Type:
Name: Someone
Time: Now
Errorcode: 42

Message Type:
Seismic instability Source: Japan
Name: Anyone
Time: Yesterday
Errorcode: 23

Message Type:
Author: Lewis Carrol
Work: The hunting of whatever
Name: Bellman
Time: 12:32:1892
Errorcode: Snark!
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The main point here is the use of the Input Record Separator ($/) to split the file into records. Then you can split on newlines and fetch the last three rows. The code above contains quite a bit of room for improvement in the regex-department (grabbing results into $1 and friends, for example), but I'll not muddy my point about the $/.

On my box, this (untidily) prints:

Someone            Now        42
Anyone            Yesterday        23
Bellman            12:32:1892        Snark!
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Good luck!

pernod
--
Mischief. Mayhem. Soap.

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Re^2: Regex to select multiple lines by beeny (Initiate) on Dec 09, 2004 at 17:02 UTC
Okie after reviewing the replies to my question, thanks to all of you. I came up with this. `sub chewitup { for($i=0; $i<$array_size; $i++){ chomp($data[$i]); if($data[$i] =~ /Message Type:/){ @details0=split / /, $data[$i]; unless($data[$i] eq $blank){ if($data[$i] =~ /Error Code:/){ @details2=split / /, $data[$i]; } if($data[$i] =~ /Transaction Time:/){ @details1=split / /, $data[$i]; } next $i; } $txname=$details0[2]; $txtime=$details1[2]; $errorcode=$details2[2]; print OUT "$txname\t\t\t$txtime\t\t$errorcode\n"; } } }` [download] Opinions please...thanks	[reply] [d/l]

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Re^2: Regex to select multiple lines
by beeny (Initiate) on Dec 09, 2004 at 17:02 UTC

sub chewitup
{
    for($i=0; $i<$array_size; $i++){
          chomp($data[$i]);
            if($data[$i] =~ /Message Type:/){
            @details0=split / /, $data[$i];
            unless($data[$i] eq $blank){
              if($data[$i] =~ /Error Code:/){
                @details2=split / /, $data[$i];
              }
              
              if($data[$i] =~ /Transaction Time:/){
                    @details1=split / /, $data[$i];
              }
              next $i;
            }
              $txname=$details0[2];
              $txtime=$details1[2];
              $errorcode=$details2[2];
              print OUT "$txname\t\t\t$txtime\t\t$errorcode\n";
          }
          
     }
}
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