regex help

[Anonymous Monk]

I'm trying to parse CLI output but occasionally have a column with no data. Any regex tricks I can use to capture that? Here is my code:

use strict;
use warnings;

use Data::Dumper;

my $string = "";
my @data = ();

while(<DATA>) {

    push @data, $_;
    $_ =~ s/\n/  /g; 

    $string .= $_;

}

my %hash = ();
foreach ( @data ) {
    chomp;
    my @array = split (/\s+/, $_);
    print Dumper(@array);
    print "\n";
}


__DATA__
Port         Alias            Oper     Admin   Speed  Duplex  Type
             (truncated)      Status   Status  (bps)
------------ ---------------- -------- ------- ------ ------- --------
+----------
vlan.0.4094                   up       up                     other
host.0.1                      up       up       10.0M         other
ge.1.1                        down     up       10.0M half    10-t    
+     rj45
ge.1.2                        down     up       10.0M half    10-t    
+     rj45
ge.1.3                        down     up       10.0M half    10-t    
+     rj45
ge.1.4                        down     up       10.0M half    10-t    
+     rj45
ge.1.5                        down     up       10.0M half    10-t    
+     rj45

[moritz]

Since it looks like fixed-size data, I recommend looking at the example in perlpacktut, it does something very similar.

[desemondo]

This does look like fixed width data (its from a telnet or ssh right?)

If it were me I'd also use a fixed width approach. Small suggestion however, add in a check that the last character of each 'field' that you extract must be space char. While this doesn't guarantee that you'll catch data from one field running into the next, it does increase your chances.

[dHarry]

Why not use one of the available CLI modules?

[grizzley]

Little shorter version (sorry, couldn't resist my perlgolfer soul...) - maybe you will find it useful.

#!perl -l

use strict;
use warnings;

use Data::Dumper;

my @data = <DATA>;
my $string = join" ", @data;

for(@data)
{
    my @array = split;
    print Dumper(@array);
}


__DATA__
Port         Alias            Oper     Admin   Speed  Duplex  Type
             (truncated)      Status   Status  (bps)
------------ ---------------- -------- ------- ------ ------- --------
+----------
vlan.0.4094                   up       up                     other
host.0.1                      up       up       10.0M         other
ge.1.1                        down     up       10.0M half    10-t    
+     rj45
ge.1.2                        down     up       10.0M half    10-t    
+     rj45
ge.1.3                        down     up       10.0M half    10-t    
+     rj45
ge.1.4                        down     up       10.0M half    10-t    
+     rj45
ge.1.5                        down     up       10.0M half    10-t    
+     rj45

But I do not know where you get empty column. I have run it, but I don't see any empty variables...

[ph0enix]

Try this if you need to use regexp ;-) Following code will create two-dimensional array from your data. Header is skipped and line with dashes (delimiter between header and data) is used for regexp pattern creation.

#!/usr/bin/perl -w
#

use strict;
use warnings;
use Data::Dumper;

my @data;
my $data = 0;
my $line;
my @size;
my $re;

while ($line = <DATA>) {
        chomp $line;                    # remove EOL
        next if ($line =~ /^\s*$/);     # skip empty lines if any
        if ($data) {                    # process data using regexp
                push @data, [ map { s/(^\s+|\s+$)//; $_ } ($line =~ /$
+re/) ];
        } elsif ($line =~ /^-/) {       # create regexp from pattern
                $data = 1;              # end of header
                @size   = map { length } split(/\s+/, $line);
                pop @size;
                $re     = '^' . join(' ', map { "(.{$_})" } @size) . '
+ (.*)';
        }
}

print Data::Dumper::Dumper(\@data);

__DATA__
Port         Alias            Oper     Admin   Speed  Duplex  Type
             (truncated)      Status   Status  (bps)
------------ ---------------- -------- ------- ------ ------- --------
+----------
vlan.0.4094                   up       up                     other
host.0.1                      up       up       10.0M         other
ge.1.1                        down     up       10.0M half    10-t    
+     rj45
ge.1.2                        down     up       10.0M half    10-t    
+     rj45
ge.1.3                        down     up       10.0M half    10-t    
+     rj45
ge.1.4                        down     up       10.0M half    10-t    
+     rj45
ge.1.5                        down     up       10.0M half    10-t    
+     rj45