use strict;
use warnings;

while(<DATA>) {
    chomp($_);

    if ($_ =~ m/\[(\d{4}\/\d{2}\/\d{2}\s+\d{2}\:\d{2}\:\d{2})\]\s+\[(\d{1,3})\]\s+ERRORMSG\s+(.*)/) {
        my $date = $1;
        my $err_no = $2;
        my $err_msg = $3;

        if ($. > 1) {
            print qq{\n};
        }
                               
        print "$date === $err_no  === $err_msg";
    }
    else {
        print qq{ $_};
    }
}

print qq{\n};


##</code><code>##

ken@ganymede: ~/tmp
$ pm_multiline_regex.pl
2012/02/16 00:08:34 === 29  === unknown error Can't insert into price table Please check Valueprice.pm line 52.
2012/02/16 00:08:34 === 39  === Invalid User
2012/02/16 00:14:52 === 105  === missing conversion rate
2012/02/16 00:14:52 === 29  === Can't use an undefined value as a HASH reference at Value.pm line 77.
ken@ganymede: ~/tmp
$