#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use XML::LibXML;

my $dom = 'XML::LibXML'->load_xml(location => shift);
my $xpc = 'XML::LibXML::XPathContext'->new($dom);
my $rpt = 1;
$xpc->registerNs("ns$rpt", 'http://www.url.com/path/for/rpt');

my $nsdevices = "//ns$rpt:device";
my @devices = $xpc->findnodes($nsdevices);
say $_->getAttribute('timestamp') for @devices;
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Or, if you find it too verbose, try XML::XSH2:

open file.xml ;
register-namespace rpt http://www.url.com/path/for/rpt ;
for //rpt:device echo @timestamp ;
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($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
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Thanks, it is a bit verbose, but your suggestion worked. I had everything in various loops depending on the xml hierarchy to bring back the values. In this case it brings back all the values at the same time, such as "value1value2value3value4" etc... for an element. Now I guess I have to figure out how to parse that or get them individually....fun :)

In this case it brings back all the values at the same time, such as "value1value2value3value4" etc... for an element.

I will admit that I am a beginner with respect to XML, but I think you took a leap of the imagination and you lost me.

Here is the program:

#!/usr/bin/perl

#  xml-libxml-ex1.pl      perl xml-libxml-ex1.pl file.xml  XML::LibXML
+ & namespaces
# From http://www.perlmonks.org/?node_id=1173200  Re: XML::LibXML & na
+mespaces by choroba on Oct 03, 2016 at 19:10 EDT

use warnings;
use strict;
use feature qw{ say };

use XML::LibXML;

my $dom = 'XML::LibXML'->load_xml(location => shift);
my $xpc = 'XML::LibXML::XPathContext'->new($dom);
my $rpt = 1;
$xpc->registerNs("ns$rpt", 'http://www.url.com/path/for/rpt');

my $nsdevices = "//ns$rpt:device";
my @devices = $xpc->findnodes($nsdevices);
say $_->getAttribute('timestamp') for @devices;

# This prints:
# 2016-01-01T00:00:00.000-00:00

__END__
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Here is the input (which I had to make modifications to, in order to get the so-called "snippet" to work with E. Choroba's program.):

<?xml version='1.0' encoding='utf-8'?>
<Notify xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http:/
+/www.w3.org/2001/XMLSchema-instance" xmlns="http://docs.oasis-open.or
+g/wsn/b-2">
<NotificationMessage>
<Topic Dialect="http://docs.oasis-open.org/wsn/t-1/TopicExpression/Sim
+ple">TOPICNAME</Topic>
<ProducerReference>
<Address xmlns="http://www.w3.org/2005/08/addressing">address</Address
+>
<Metadata xmlns="http://www.w3.org/2005/08/addressing">
<ns2:MessageID xmlns:ns2="http://www.w3.org/2005/08/addressing">msgid<
+/ns2:MessageID>
</Metadata>
</ProducerReference>
<Message>
<ns1:rpt xmlns:ns1="http://www.url.com/path/for/rpt">
<ns1:reportObject>
<ns1:device timestamp="2016-01-01T00:00:00.000-00:00">
</ns1:device>
</ns1:reportObject>
</ns1:rpt>
</Message>
</NotificationMessage>
</Notify>
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I named the input file file.xml

Here is the output:

2016-01-01T00:00:00.000-00:00
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Sorry, but I see one value. Perhaps I am not playing with a full deck, i.e., you have a different input file than I have, and you are asking a question regarding output that you have obtained from your input file, but I can only guess what your input file looks like.

Anyhow, I was able to get E. Choroba's program to work on my machine which runs Strawberry Perl, and I have learned something from him, yet again.