Multiple Line Regex Not Working

ImJustAFriend has asked for the wisdom of the Perl Monks concerning the following question:

Hello again monks. Now that I have the right log file to code against, I have come across another issue. I have a log formatted like this:

<13>Nov 15 21:26:00 OamCOMM[365626]:
TIMESTAMP=Thu Nov 15 21:26:00 2018

MSGCLS=OAMOPE
Title=OAM Create OPERATION
Severity=Inform
message={username:xxxxxxxx@xxxxxxxxxxxxxxxxxxx;
 causeDISTINGUISH_NAME=label=x,label=x,;label=x,label=xxxxxxxxxxxxxxx,
+label=x,label=xxxx
USER_LABEL=
******************* parameters after change =*******************
label=xxxxxxxxxxxxx
label=xxxxxxxxxxxxxxxxxxxxxxx
label=xxxxxxxxxxxxxxxxxxxxxxxxxxxx
label=sxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
label=xxxxxxxxxxxx
******************* xxxxxxxxxxxx =*******************
label=x
}
Message Id=xxxxxxxx
[download]

For troubleshooting purposes I extracted one "chunk" of the log and put it into a text file t.txt. I then crafted t.pl to see if I could get the coding to work without impacting my larger script. Basically, I need to capture everything between "message=" and "Message Id" for this log entry. I am thinking in an array for processing after extraction. I have literally tried 40 different ideas, either my own or found on internet search, and nothing works. Here's my t.pl code I'm trying to make work:

#!/bin/perl

use strict;
use warnings;
use Data::Dumper;

my $mlsf = "t.txt";
my @res;

open IN, "<", $mlsf or die "IN: $!\n";

while (my $mls = <IN>) {
        @res = $mls =~ m/^.*message=(.*?)Message Id.*$/gs;
}

print Dumper (\@res);
[download]

When I execute this script, I get:

$VAR1 = [];
[download]

Anyone have any ideas?

Comment on Multiple Line Regex Not Working Select or Download Code

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Re: Multiple Line Regex Not Working by jwkrahn (Abbot) on Nov 15, 2018 at 22:34 UTC
You are reading the file one line at a time so your regular expression will not work. This should work: `while ( my $mls = <IN> ) { push @res, $mls if $mls =~ /^message=/ .. $mls =~ /^Message Id/; }` [download]	[reply] [d/l]
Re^2: Multiple Line Regex Not Working by ImJustAFriend (Scribe) on Nov 16, 2018 at 12:33 UTC
That worked like a champ!! Thank you!!	[reply]
Re: Multiple Line Regex Not Working by kcott (Archbishop) on Nov 16, 2018 at 07:12 UTC
G'day ImJustAFriend, Instead of reading one line at a time, you could read one chunk at a time by setting `$/` (see perlvar: $/). Here's a quick-and-dirty example script to demonstrate the technique. I pared down your posted data substantially; duplicated it; then labelled with "CHUNK 1" and "CHUNK 2". #!/usr/bin/env perl use strict; use warnings; { local $/ = "\nMessage Id"; while (<DATA>) { chomp; /^message=(.*)\z/ms && print "$1\n"; } } __DATA__ <13>Nov 15 21:26:00 OamCOMM[365626]: TIMESTAMP=Thu Nov 15 21:26:00 2018 ... Severity=Inform message={username:xxxxxxx... causeDISTINGUISH_NAME=... ... CHUNK 1 ... label=x } Message Id=xxxxxxxx <13>Nov 15 21:26:00 OamCOMM[365626]: TIMESTAMP=Thu Nov 15 21:26:00 2018 ... Severity=Inform message={username:xxxxxxx... causeDISTINGUISH_NAME=... ... CHUNK 2 ... label=x } Message Id=xxxxxxxx [download] Output: `{username:xxxxxxx... causeDISTINGUISH_NAME=... ... CHUNK 1 ... label=x } {username:xxxxxxx... causeDISTINGUISH_NAME=... ... CHUNK 2 ... label=x }` [download] — Ken	[reply] [d/l] [select]