#!/usr/bin/perl
use warnings;
use strict;

my $BE_temp = '+--------------+-------------+
| version_name | schema_name |
+--------------+-------------+
| dsmgt_03_03  | dsmgt_03    |
+--------------+-------------+
';

$BE_temp =~ m/^\|\s(\w+_\d+)\s+\|\s+(\w+)\s+\|$/m;
my $LSV = $1;
my $LSN = $2;

print "[$LSV] [$LSN]\n";
[download]

Note that you are filling the variables even if the regex does not match. It might be better to fix that, plus avoid the $1 and $2:

if (my ($LSV, $LSN) = $BE_temp =~ m/^\|\s(\w+_\d+)\s+\|\s+(\w+)\s+\|$/
+m) {
    print "[$LSV] [$LSN]\n";
}
[download]

Another approach:

>perl -wMstrict -le
"my $s = 'dsmgt dsmgt_ dsmgt_9 dsmgt99 dsmgt__99 dsmgt_999 '
       . 'dsmgt_12_34_56dsmgt_12_34 dsmgt_12';
 print qq{'$s'};
 ;;
 my $rx_dsmgt = qr{ (?<! [[:alpha:]]) dsmgt (?: _ \d\d)+ (?! \d) }xms;
 ;;
 my @pieces = $s =~ m{ $rx_dsmgt }xmsg;
 printf qq{'$_' } for @pieces;
"
'dsmgt dsmgt_ dsmgt_9 dsmgt99 dsmgt__99 dsmgt_999 dsmgt_12_34_56dsmgt_
+12_34 dsmgt_12'
'dsmgt_12_34_56' 'dsmgt_12_34' 'dsmgt_12'
[download]

OK, figured it out. My $BE_temp was being set by capturing the output of a MySQL query. I changed the output format of the query with the "-E" flag. I was then able to RE the LSV and LSN appropriately. Code from my test script and output below...

$output = $cli->cmd("/usr/mysql/bin/mysql -E -uuser -ppass -D targetdb
+ -e \"select * from table;\" | tail -2");
$temp = $output;

print "\ntemp\n----------------\n$temp\n";
my ($LSV, $LSN) = $temp =~ m/^.*: (\w+).*: (\w+)/s;
print "LSV: $LSV\nLSN: $LSN\n";
[download]

Results

temp
----------------
version_name: dsmgt_03_03
 schema_name: dsmgt_03

LSV: dsmgt_03_03
LSN: dsmgt_03
[download]

my ($LSV, $LSN) = $temp =~ m/^.*: (\w+).*: (\w+)/s;
print "LSV: $LSV\nLSN: $LSN\n";


This still has the problem (IMHO) that the success of the match is not tested before using the 'results' of the match. Please see my reply above.

I am getting "uninitialized value" errors every time with this script. I just changed the code to the following:

my ($LSV, $LSN) = $BE_temp =~ m/^\|\s(\w+_\d+)\s+\|\s+(\w+)\s+\|$/m;
if ( $LSV =~ m/dsmgt_03_03/ ) {
    print "LSV Match\n";
} else {
    print "LSV Fail\n";
}
[download]

When I run my script now, I get the following:

Use of uninitialized value $LSV in pattern match (m//) at C:\Users\civ
+ey\Documents\Perl\SDM401-LDAP_Config.pl line 405, <STDIN> line 2.
LSV Fail
[download]

I will move the relevant pieces of code to a test script and see if that helps... any other ideas?

Thanks!!

my ($LSV, $LSN) = $BE_temp =~ m/^\|\s(\w+_\d+)\s+\|\s+(\w+)\s+\|$/m;
if ( $LSV =~ m/dsmgt_03_03/ ) { ... }


If the initial match against  $BE_temp fails, the subsequent match against  $LSV will produce a "Use of uninitialized value $LSV in pattern match ..." warning (not error) because  $LSV et al are undefined. The initial match should be tested in some way and subsequent matches (or uses of the extracted strings) made dependent on a successful initial match, e.g.:

if (my ($LSV, $LSN) = $BE_temp =~ m/^\|\s(\w+_\d+)\s+\|\s+(\w+)\s+\|$/
+m) {
    do_something_with($LSV);
    do_something_with($LSN);
    }
[download]

What results are you expecting?