Matching of data from output table - perl

Question

We need to match certain data element by element that is an output in tabular form obtained on the command prompt.The following is the approach being currently followed wherein the $Var contains the output. Is there an optimal way of doing this without directing the command output to file.
Please share your thoughts.
$Var = "iSCSI Storage LHN StgMgmt Name IP Name
==============================================================
0 Storage_1 15.178.209.194 admin
1 acct-mgmt 15.178.209.194 storage1
2 acct-mgmt2 15.178.209.194 storage2";
#tab = split("\n",$Var);
foreach (#tab) {
next if ($_ !~ /^\d/);
$_ =~ s/\s+//g;
$first=0 if($_ =~ /Storage/i && /15.178.209.194/);
push(#Array, $_); }

Answer 1

$_ =~ /Storage/i && /15.178.209.194/ is silly. That gets broken up like this: ($_ =~ /Storage/i) && (/15.178.209.194/). Either use $_ consistently or don't - the // and s/// operators automatically operate on $_.
Also you should know that in the regex /15.178.209.194/, the .s are being interpreted as any character. Either escape them or use the index() function.
Additionally, I would recommend that you separate each line using split(). This allows you to compare each individual column. You can use split() with a regex like so: #array = split(/\s+/, $string);.
Finally, I'm not really sure what $first is for, but I notice that all three sample lines in that input trigger $first=0 as they all contain that IP and the string "storage".

Answer 2

If I understand you correctly you want to invoke your script like this:
./some_shell_command | perl perl_script.pl
What you want to use is the Perl diamond operator <>:
#!/usr/bin/perl
use strict;
use warnings;
my $first;
my #Array;
for (<>) {
next unless /^\d/;
s/\s+/ /g;
$first = 0 if /Storage/i && /15.178.209.194/;
push(#Array, $_);
}
I've removed the redundant uses of $_ and fixed your substitution, since you probably don't want to remove all spaces.