Editing XML files - batch-file

Question

I have some XML files and I need to edit them automatically.
For example
<Content>
<Texts>
<Text id="1">
<en value="blaabla" />
</Text>
<Text id="2">
<en value="blablablablal" />
</Text>
</Texts>
</Content>
I need to copy "en value" lines and add these lines to their under line but with one change.
So when processing done, result should be that:
<Content>
<Texts>
<Text id="1">
<en value="blablabla" />
<fr value="blablabla" />
</Text>
<Text id="2">
<en value="blablablablal" />
<fr value="blablablablal" />
</Text>
</Texts>
</Content>

Answer 1

You could use this XSLT to transform your XML files:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="1.0">
<xsl:output indent="yes"/>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="en[#value]">
<xsl:copy>
<xsl:apply-templates select="#*|node()" />
</xsl:copy>
<fr value="{#value}"/>
</xsl:template>
</xsl:stylesheet>

Answer 2

$ sed '/<en /p' data.txt | awk '/<en /{if(x++%2)sub(/<en /, "<fr ")}1'
<Content>
<Texts>
<Text id="1">
<en value="blaabla" />
<fr value="blaabla" />
</Text>
<Text id="2">
<en value="blablablablal" />
<fr value="blablablablal" />
using sed to duplicate line which contains <en
using awk to change the odd <en to <fr
WARNING: <en ... /> must be one line.