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

I have taken another approach to what I think you are trying to do. Hopefully you can use this to achieve what you want.

use strict;
use warnings;

my @tmp;
my @keep;
my $first_time = 1;

while (my $a_line = <DATA>) {
    chomp $a_line;
    push @tmp, $a_line;
    if ( $a_line =~ /^\d+\s+\D+/ ) 
    {
        if ($first_time) 
        {
            $first_time = 0;
        }
        else 
        {
                #we have a new host master record
                #process the data from the previous host
            process_previous(\@tmp);
            @keep = (@keep, @tmp);
            @tmp =();
        }
    }
}

process_previous(\@tmp);
@keep = (@keep, @tmp);
@tmp=();

print "$_\n" for @keep;
exit(0);

#----------------- SUBS ----------------------------
sub process_previous {
    my $array_ref = shift;
    my $keep_this_data = 0;
    foreach my $elem(@$array_ref) 
    {
        if ($elem !~ /\d:\d:\d$/ ) 
        {
            $keep_this_data = 1;
            last;
        }
    }

    if (!$keep_this_data) 
    {
        #empty the array
        @$array_ref = ();
    }
}

__DATA__
7 hostname12 Generic-legacy 10000000AB210ACF6 ---
                             10000000AB210ACF4 2:5:4
                             10000000AB210ACF4 2:3:4
                             10000000AB210ACF6 3:5:4
9 hostname13 Generic        10000000AB2A3006A 3:5:2
                             10000000AB2A30068 2:5:2
23 srvernam   Generic-legacy 5001438002A3004A 3:3:3
                             5001438002A3004A ---
                             5001438002A30048 2:3:3
                             5001438002A30048 2:5:2
                             5001438002A30048 2:5:2
9 hostname13 Generic        10000000AB2A3006A 3:5:2
                             10000000AB2A30068 2:5:2
21 HOSTNAME   Generic
9 hostname13 Generic        10000000AB2A3006A 3:5:2
                             10000000AB2A30068 2:5:2

[download]

output

7 hostname12 Generic-legacy 10000000AB210ACF6 ---
                             10000000AB210ACF4 2:5:4
                             10000000AB210ACF4 2:3:4
                             10000000AB210ACF6 3:5:4
23 srvernam   Generic-legacy 5001438002A3004A 3:3:3
                             5001438002A3004A ---
                             5001438002A30048 2:3:3
                             5001438002A30048 2:5:2
                             5001438002A30048 2:5:2
21 HOSTNAME   Generic

[download]

I hope this helps.

Arnaud

Comment on Re: Regex to extract certain lines only from command output/text file. Select or Download Code

Replies are listed 'Best First'.
Re^2: Regex to extract certain lines only from command output/text file. by Anonymous Monk on Mar 08, 2013 at 00:55 UTC
arnaud99 Check your script, the output indicated in your post is really different to what your code really shows. Below is the output of your script: `7 hostname12 Generic-legacy 10000000AB210ACF6 --- 10000000AB210ACF4 2:5:4 10000000AB210ACF4 2:3:4 10000000AB210ACF6 3:5:4 9 hostname13 Generic 10000000AB2A3006A 3:5:2 5001438002A3004A --- 5001438002A30048 2:3:3 5001438002A30048 2:5:2 5001438002A30048 2:5:2 9 hostname13 Generic 10000000AB2A3006A 3:5:2 10000000AB2A30068 2:5:2 21 HOSTNAME Generic` [download] According, to the OP, `9 hostname13 Generic 10000000AB2A3006A 3:5:2 10000000AB2A30068 2:5:2` [download] Is not suppose to be shown in the final output. Your script even modified some info. like this: `9 hostname13 Generic 10000000AB2A3006A 3:5:2 5001438002A3004A --- 5001438002A30048 2:3:3 5001438002A30048 2:5:2 5001438002A30048 2:5:2 9 hostname13 Generic 10000000AB2A3006A 3:5:2 10000000AB2A30068 2:5:2` [download] The OP has only one "9 hostname13 Generic", so how did it become two, in the final output.	[reply] [d/l] [select]
Re^3: Regex to extract certain lines only from command output/text file. by arnaud99 (Beadle) on Mar 08, 2013 at 03:16 UTC
Hi, In response to: The OP has only one "9 hostname13 Generic", so how did it become two, in the final output. I added an extra one in the __DATA__ section, for testing purposes. Only one was showing in the output (the last one in __DATA__ , due to an empty line at the end of the same __DATA__ section. (The fix is also posted in one of the replies) Thanks. Arnaud	[reply]