trying HoH

mikejones has asked for the wisdom of the Perl Monks concerning the following question:

Input: system command

Output: HoH

Problem: system command with lots of garbage output.

Goal: To create a HoH with SAN_VC0_## as the key and the hdisk string plus its serial as the values.

All I need is a single hdisk# string from the below system command output. Thank you! Here is what I have tried:

use strict;
for my $lun ( ('SAN_VC0_42','SAN_VC0_43') ) {
    $luns_to_hdisk {$lun} = 
        { grep /hdisk\d+/, qx(vxdisk list $lun) } ;
}

print Dumper(\%luns_to_hdisk);

$VAR1 = {
          'SAN_VC0_43' => {
                            'hdisk855   state=enabled
' => 'hdisk920  state=enabled
',
                            'hdisk587   state=enabled
' => 'hdisk652  state=enabled
',
                            'hdisk51    state=enabled
' => 'hdisk116  state=enabled
',
                            'hdisk319   state=enabled
' => 'hdisk384  state=enabled
'
                          },
          'SAN_VC0_42' => {
                            'hdisk571   state=enabled
' => 'hdisk636  state=enabled
',
                            'hdisk35    state=enabled
' => 'hdisk100  state=enabled
',
                            'hdisk303   state=enabled
' => 'hdisk368  state=enabled
',
                            'hdisk839   state=enabled
' => 'hdisk904  state=enabled
'
                          }
        };
[download]

Output of system command:

$ vxdisk list SAN_VC0_42
Device:    SAN_VC0_42
devicetag: SAN_VC0_42
type:      auto
info:      format=none
flags:     online ready private autoconfig invalid
pubpaths:  block=/dev/vx/dmp/SAN_VC0_42 char=/dev/vx/rdmp/SAN_VC0_42
Multipathing information:
numpaths:   8
hdisk35 state=enabled
hdisk100        state=enabled
hdisk303        state=enabled
hdisk368        state=enabled
hdisk571        state=enabled
hdisk636        state=enabled
hdisk839        state=enabled
hdisk904        state=enabled
[download]

Comment on trying HoH Select or Download Code

Replies are listed 'Best First'.
Re: trying HoH by gone2015 (Deacon) on Nov 11, 2008 at 01:47 UTC
OK, so let's unpack what you did: `for my $lun ( ('SAN_VC0_42','SAN_VC0_43') ) { $luns_to_hdisk {$lun} = { grep /hdisk\d+/, qx(vxdisk list $lun) } +; } ;` [download] the `qx(vxdisk list $lun)` is invoked in List Context, so will return a list, each entry of which is one line as returned by the `vxdisk` command -- complete with line-ending. the `grep` returns a list which is a subset of the list returned by `qx`, selecting the entries which match `/hdisk\d+/` that is enclosed by `{}`, which in this case comprise an anonymous hash constructor -- constructing a hash with the even numbered entries that matched `/hdisk\d+/` as keys, and the odd numbered entries as values. a reference to that anonymous hash is assigned to `$luns_to_hdisk{$lun}` that is done for `$lun` set to `'SAN_VC0_42'` and then `'SAN_VC0_43'` so much, so straightforward. I guess that's not what you intended ? What did you have in mind ? If you want `$luns_to_hdisk{$lun}` to be a list of the `/hdisk\d+/` lines, you are very nearly there... you just need the anonymous list constructor `[]`, not the anonymous hash constructor `{}`. That would be an HoL, though -- which is not what you were apparently wanting ? You may want to consider a `chomp` somewhere or other to remove the line-endings from the selected lines. It's not clear whether you want the '`state=enabled`' part, and if not you need a little extra code there.	[reply] [d/l] [select]
Re: trying HoH by toolic (Bishop) on Nov 11, 2008 at 02:06 UTC
You did not show us what you want the contents of your HoH to be. Is is something like this? `$VAR1 = { 'SAN_VC0_42' => { 'hdisk368' => 'state=enabled', 'hdisk303' => 'state=enabled', 'hdisk636' => 'state=enabled', 'hdisk35' => 'state=enabled', 'hdisk904' => 'state=enabled', 'hdisk571' => 'state=enabled', 'hdisk100' => 'state=enabled', 'hdisk839' => 'state=enabled' } };` [download] If so, then this more verbose code will accomplish that: `my @vxdisk_lines = qx(vxdisk list $lun); chomp @vxdisk_lines; my @hdisks = grep {/hdisk\d+/} @vxdisk_lines; my %h; for (@hdisks) { my ($k, $v) = split; $h{$k} = $v; } $luns_to_hdisk{$lun} = \%h;` [download]	[reply] [d/l] [select]
Re^2: trying HoH by mikejones (Scribe) on Nov 11, 2008 at 02:27 UTC
You all definitely helped! Thx agn. I want my end result to look like b/c all I need is one hdisk string b/c they are all different logical paths to the same LUN. I don't need the 'state=enabled' part and tried using (split)[0] but failed. Once I have this I will then integrate another system command (or a 2nd hash value) on the value hdisk368 for example to get its serial number. `END_RESULT $VAR1 = { 'SAN_VC0_42' => { 'hdisk368' => 'state=enabled', } };` [download] I was playing with, but was side-tracked. `print ((<DATA>)[-1]); __DATA__ Device: SAN_VC0_42 devicetag: SAN_VC0_42 type: auto info: format=none flags: online ready private autoconfig invalid pubpaths: block=/dev/vx/dmp/SAN_VC0_42 char=/dev/vx/rdmp/SAN_VC0_42 Multipathing information: numpaths: 8 hdisk35 state=enabled hdisk100 state=enabled hdisk303 state=enabled hdisk368 state=enabled hdisk571 state=enabled hdisk636 state=enabled hdisk839 state=enabled hdisk904 state=enabled` [download]	[reply] [d/l] [select]
Re: trying HoH by kyle (Abbot) on Nov 11, 2008 at 01:53 UTC
I can't tell what you want the end structure to look like. My guess is that this is what you want: `$luns_to_hdisk {$lun} = { map { chomp; split } grep { /hdisk\d+/ } qx(vxdisk list $lun) }` [download]	[reply] [d/l]