forward variable...

Bennco99 has asked for the wisdom of the Perl Monks concerning the following question:

How do I take "$objItem->{DNSHostName}" and make it a variable to use later in the script. It seems to go away after the foreach is done.

use Win32::OLE('in');
use constant wbemFlagReturnImmediately => 0x10;
use constant wbemFlagForwardOnly => 0x20;

$computer = "10.1.50.57";
$objWMIService = Win32::OLE->GetObject
    ("winmgmts:\\\\$computer\\root\\CIMV2") or die "WMI connection fai
+led.\n";
$colItems = $objWMIService->ExecQuery
    ("SELECT * FROM Win32_NetworkAdapterConfiguration","WQL",wbemFlagR
+eturnImmediately | wbemFlagForwardOnly);

foreach my $objItem (in $colItems)
{
            next unless $objItem->{Description} eq "Intel 8255x-based 
+Integrated Fast Ethernet";
      print "DNS Host Name: $objItem->{DNSHostName}\n";
      print "IP Address: " . join(",", (in $objItem->{IPAddress})) . "
+\n";
      print "MAC Address: $objItem->{MACAddress}\n";
      print "\n";

}
[download]

Something like..

$pcname = "$objItem->{DNSHostName}"
[download]

Thank you

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Re: forward variable... by ikegami (Patriarch) on Aug 10, 2006 at 16:24 UTC
You gave the answer already (except the quotes are not needed). `my $pcname; foreach my $objItem (in $colItems) { next unless $objItem->{Description} eq "..."; $pcname = $objItem->{DNSHostName}; last; }` [download] One catch. What happens if there 0 or 2+ matching records? You could store them in an array. `my @pcnames; foreach my $objItem (in $colItems) { next unless $objItem->{Description} eq "..."; push(@pcnames, $objItem->{DNSHostName}); }` [download] By the way, the first snippet can also be written as `use List::Util qw( first ); my $pcname = map { $_->{DNSHostName} } first { $_->{Description} eq "..." } in $colItems;` [download] The second snippet can also be written as `my @pcnames = map { $_->{DNSHostName} } grep { $_->{Description} eq "..." } in $colItems;` [download] If you're expecting one, and only one match, you could easily check the number of entries in @pcnames. `my @pcnames = map { $_->{DNSHostName} } grep { $_->{Description} eq "..." } in $colItems; die("Unable to find network card\n"); if @pcnames == 0; warn("Found multiple network cards. Using the first one\n") if @pcnames != 1; my $pcname = $pcnames[0];` [download]	[reply] [d/l] [select]
Re: forward variable... by prasadbabu (Prior) on Aug 10, 2006 at 16:23 UTC
Hi Bennco99, ~~If i understood your question correctly, i think you are looking for symbolic references, which you have to avoid fully. Instead you can use hash or array to use it later. Take a look at perlvar.~~ `$hash{pcname}= "DNSHostName"` [download] ~~Here are some nodes that may help you to understand better symbolic references, Re: Dynamically naming and creating hashes~~ Update: Sorry, misunderstood the question. Ignore this. Ikegami thanks for pointing out :) Prasad	[reply] [d/l]