Regex to replace everything that doesn't match - regex

Question

Sample <AAA:BBB CCC:DDD EEE:FFF><GGG:HHH III:JJJ><KKK>
What I want is a substituion that removes everything except <BBB><HHH><KKK>
I've tried loads of things and just keep falling over
If its easier to one brace at a time that would be fine
As you can probably guess its XML using LibXML and I'm parsing all the elements against a list of paths and nodes in arrays. I just want the node name not things like
<com.fnf:NodeName/> needs to be <NodeName/>
or worse still <\com.com.com:NodeName xmlns:com.com.com="http://www.some.domain"> just needs to say <NodeName>

Answer 1

I think this short program will do what you need. It uses XML::Twig to process the XML data, and defines a twig handler which is called for all elements in the data, and removes the element's namespace prefix and all attributes.
I've had to make a guess at what your XML data really looks like, as what you show in your question is far from being valid XML.
use strict;
use warnings;
use XML::Twig;
my $twig = XML::Twig->new;
$twig->setTwigHandler(_all_ => sub {
$_->set_name($_->local_name);
$_->del_atts;
});
$twig->parse( \*DATA );
$twig->print(pretty_print => 'indented');
__DATA__
<root>
<aaa:bbb ccc="ddd" eee="fff">
<ggg:hhh iii="jjj">
<kkk></kkk>
</ggg:hhh>
</aaa:bbb>
</root>
output
<root>
<bbb>
<hhh>
<kkk></kkk>
</hhh>
</bbb>
</root>

Answer 2

Use XML::Parser and set Namespaces to true:
Namespaces
This is an Expat option. If this is set to a true value, then namespace processing is done during the parse. See "Namespaces" in XML::Parser::Expat for further discussion of namespace processing.
…
When this option is given with a true value, then the parser does namespace processing. By default, namespace processing is turned off. When it is turned on, the parser consumes xmlns attributes and strips off prefixes from element and attributes names where those prefixes have a defined namespace. A name's namespace can be found using the "namespace" method and two names can be checked for absolute equality with the "eq_name" method.

Answer 3

An idea: this can be done with an xsl transformation:
the xsl file:
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output indent="yes" method="xml" encoding="utf-8" omit-xml-declaration="yes"/>
<!-- template for all elements -->
<xsl:template match="*">
<!-- local-name() gets the tagname without namespace -->
<xsl:element name="{local-name()}">
<xsl:apply-templates select="node()"/>
</xsl:element>
</xsl:template>
<!-- template to copy all that is not a tag or an attribute -->
<xsl:template match="comment() | text() | processing-instruction()">
<xsl:copy/>
</xsl:template>
</xsl:stylesheet>
The perl code:
#!/usr/bin/perl
use strict;
use warnings;
use XML::LibXSLT;
use XML::LibXML;
my $xslt = XML::LibXSLT->new();
my $source = XML::LibXML->load_xml(location => 'removens.xml');
my $style_doc = XML::LibXML->load_xml(location => 'removens.xsl');
my $stylesheet = $xslt->parse_stylesheet($style_doc);
my $results = $stylesheet->transform($source);
print $stylesheet->output_as_bytes($results);
or instead of using perl, you can use directly xsltproc in a terminal:
xsltproc removens.xsl removens.xml