Perl XML, find matching condition and grep lines and put the lines somewhere else

Shell Programming and Scripting
1

Hi,

my xml files looks something like this

<Instance Name="New York">
      <Description></Description>
      <Instance Name="A">
        <Description></Description>
        <PropertyValue Key="false" Name="Building A" />
      </Instance>
      <Instance Name="B">
        <Description></Description>
        <PropertyValue Key="false" Name="Building B" />
      </Instance>
      <PropertyValue Key="false" Name="random" />
      <PropertyValue Key="false" Name="blabla" />
      <PropertyValue Key="false" Name="blabla2" />
    </Instance>

I need to grep all the lines between </Instance> and </Instance> {the 3 proeprty values, there cna be 4 or more, and place them on top between </Description> and <Instance, so it becomes like this

<Instance Name="New York">
<Description></Description>
<PropertyValue Key="false" Name="random" />
<PropertyValue Key="false" Name="blabla" />
<PropertyValue Key="false" Name="blabla2" />
<Instance Name="A">
<Description></Description>
<PropertyValue Key="false" Name="Building A" />
</Instance>
<Instance Name="B">
<Description></Description>
<PropertyValue Key="false" Name="Building B" />
</Instance>
</Instance>
[/CODE]

For the notes, There can be more than 1 parent in file. The Instance name will also be different than New York, but what I need to highlight is the string matching condition. In short, a complete file may look like this

<Instance Name="New York">
      <Description></Description>
      <Instance Name="A">
        <Description></Description>
        <PropertyValue Key="false" Name="Building A" />
      </Instance>
      <Instance Name="B">
        <Description></Description>
        <PropertyValue Key="false" Name="Building B" />
      </Instance>
      <PropertyValue Key="false" Name="random" />
      <PropertyValue Key="false" Name="blabla" />
      <PropertyValue Key="false" Name="blabla2" />
    </Instance>
<Instance Name="Mumbai">
       <Description></Description>
      <Instance Name="C">
         <Description></Description>
         <PropertyValue Key="false" Name="Building C" />
       </Instance>
       <Instance Name="D">
         <Description></Description>
         <PropertyValue Key="false" Name="Building D" />
      </Instance>
      <PropertyValue Key="false" Name="absolute" />
      <PropertyValue Key="false" Name="perl" />
      <PropertyValue Key="false" Name="xml" />
    </Instance>

In which case, the result needs to be like this

<Instance Name="New York">
      <Description></Description>
      <PropertyValue Key="false" Name="random" />
      <PropertyValue Key="false" Name="blabla" />
      <PropertyValue Key="false" Name="blabla2" />
       <Instance Name="A">
        <Description></Description>
        <PropertyValue Key="false" Name="Building A" />
      </Instance>
      <Instance Name="B">
        <Description></Description>
        <PropertyValue Key="false" Name="Building B" />
      </Instance>
    </Instance>
<Instance Name="Mumbai">
       <Description></Description>
      <PropertyValue Key="false" Name="absolute" />
      <PropertyValue Key="false" Name="perl" />
      <PropertyValue Key="false" Name="xml" />
       <Instance Name="C">
         <Description></Description>
         <PropertyValue Key="false" Name="Building C" />
       </Instance>
       <Instance Name="D">
         <Description></Description>
         <PropertyValue Key="false" Name="Building D" />
       </Instance>
    </Instance>

I wonder if this is possible, please help. Thank you very much.Really appreciate it.

2

Try this

#!/usr/bin/perl

use XML::LibXSLT;
use XML::LibXML;

my $parser = XML::LibXML->new();
my $xslt = XML::LibXSLT->new();

my $source = $parser->parse_file('example.xml');
my $style_doc = $parser->parse_file('example.xsl');

my $stylesheet = $xslt->parse_stylesheet($style_doc);

my $results = $stylesheet->transform($source);

print $stylesheet->output_string($results);

For this to work you input document (example.xml) needs to be well-formed. Thus I have added a root element called "Instances".

<Instances>
   <Instance Name="New York">
      <Description></Description>
      <Instance Name="A">
         <Description></Description>
         <PropertyValue Key="false" Name="Building A" />
      </Instance>
      <Instance Name="B">
         <Description></Description>
         <PropertyValue Key="false" Name="Building B" />
      </Instance>
      <PropertyValue Key="false" Name="random" />
      <PropertyValue Key="false" Name="blabla" />
      <PropertyValue Key="false" Name="blabla2" />
   </Instance>
   <Instance Name="Mumbai">
      <Description></Description>
      <Instance Name="C">
         <Description></Description>
         <PropertyValue Key="false" Name="Building C" />
      </Instance>
      <Instance Name="D">
         <Description></Description>
         <PropertyValue Key="false" Name="Building D" />
      </Instance>
      <PropertyValue Key="false" Name="absolute" />
      <PropertyValue Key="false" Name="perl" />
      <PropertyValue Key="false" Name="xml" />
   </Instance>
</Instances>

Here is the stylesheet (example.xsl). This can handle any number of PropertyValue elements as requested.

<xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

   <xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>

   <xsl:strip-space elements="*" />

   <xsl:template match="/Instances/Instance">
       <xsl:element name='{name()}'>
           <xsl:copy-of select="Description"/>
           <xsl:for-each select="child::PropertyValue">
              <xsl:copy-of select="." />
           </xsl:for-each>
           <xsl:for-each select="child::Instance">
              <xsl:copy-of select="." />
           </xsl:for-each>
       </xsl:element><xsl:text>
</xsl:text>
   </xsl:template>

</xsl:stylesheet>

and here is the result document

<Instance>
  <Description/>
  <PropertyValue Key="false" Name="random"/>
  <PropertyValue Key="false" Name="blabla"/>
  <PropertyValue Key="false" Name="blabla2"/>
  <Instance Name="A">
    <Description/>
    <PropertyValue Key="false" Name="Building A"/>
  </Instance>
  <Instance Name="B">
    <Description/>
    <PropertyValue Key="false" Name="Building B"/>
  </Instance>
</Instance>
<Instance>
  <Description/>
  <PropertyValue Key="false" Name="absolute"/>
  <PropertyValue Key="false" Name="perl"/>
  <PropertyValue Key="false" Name="xml"/>
  <Instance Name="C">
    <Description/>
    <PropertyValue Key="false" Name="Building C"/>
  </Instance>
  <Instance Name="D">
    <Description/>
    <PropertyValue Key="false" Name="Building D"/>
  </Instance>
</Instance>
3

had problem with perl when executing it. I installed the necessary perl modules but it failed to run. Is there an alternative for this?

4

That is strange. What errors were you getting?

Sure, you can use any XSLT processor.

For example, from a GNU/Linux command line:

5

Perl crashed basically. I wonder if there are any other methods to do this beside using that XSLT.