Re: Regex to extract certain lines only from command output/text file.

[perl514]

Hi Monks,

First of all, thank you very much for your help on this issue. I tried all the options above and they worked great. however, I wanted to crack the issue without using much of the techniques mentioned above, so I tried a different approach and it worked !!. What also helped is, this time, I could safely ignore the line that has blanks next to it...

So given below is the line of output.

C:\perlscripts>more 3par.txt
Id Name Persona -WWN/iSCSI_Name- Port

2 hpux-host2 HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 ---
                         1122334455667788 ---
                         1122334455667799 4:3:1
3 hpux-host3 HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 ---
                         1122334455667788 ---
                         1122334455667799 ---
4 hpux-host4 HPUX-legacy 1122334455667788 ---
                         1122334455667799 3:3:1
                         1122334455667788 1:3:1
                         1122334455667799 4:3:1
5 hpux-host5 HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 3:3:1
                         1122334455667788 1:3:1
                         1122334455667799 4:3:1
5 hpux-host6 HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 3:3:1
                         1122334455667788 1:3:1
                         1122334455667799 4:3:1
7 hpux-host HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 3:3:1
                         1122334455667788   ---
                         1122334455667799 4:3:1

From this, I only had to take out those hosts which have one or more --- in the output. Here's my attempt:

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

my $space_sep_FH;
my @para;

open($space_sep_FH,'>', 'space_sep.txt') or die "Error:$!.$^E";
while (<>) {
    
    next if /Id Name Persona -WWN\/iSCSI_Name- Port/;
    s/(^[ 0-9])+/\n\n$1/;
    
    print $space_sep_FH "$_";
    
}

print "Done writing to space_sep.txt.\n";

$/ = "\n\n";
open($space_sep_FH,'<', 'space_sep.txt') or die "Error:$!.$^E";
@para = <$space_sep_FH>;

foreach my $para (@para)
{
    print "$para" if $para =~ /---/;
}

And here is the output!!

C:\perlscripts>perl test_3par_tp.pl 3par.txt
Done writing to space_sep.txt.

2 hpux-host2 HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 ---
                         1122334455667788 ---
                         1122334455667799 4:3:1


3 hpux-host3 HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 ---
                         1122334455667788 ---
                         1122334455667799 ---


4 hpux-host4 HPUX-legacy 1122334455667788 ---
                         1122334455667799 3:3:1
                         1122334455667788 1:3:1
                         1122334455667799 4:3:1


7 hpux-host HPUX-legacy 1122334455667788 2:3:1
                         1122334455667799 3:3:1
                         1122334455667788   ---
                         1122334455667799 4:3:1


C:\perlscripts>

It now feels better to crack it in another way !!

May be my newly bought T430 was an inspiration :)

Perl is really a great language, it lets you do things your way.