Process maven's pom xml file with xmlstarlet

General command  to get version of certain plugin dependency from pom file:

xmlstarlet sel -N pom=http://maven.apache.org/POM/4.0.0 -t -m "/pom:project/pom:build/pom:pluginManagement/pom:plugins/pom:plugin[pom:artifactId='maven-checkstyle-plugin']/pom:dependencies/pom:dependency[pom:artifactId='checkstyle']/pom:version" -v . pom.xml

Examples for editing and selection are at:
https://github.com/sevntu-checkstyle/sevntu.checkstyle/blob/master/pom-version-bump.sh

https://github.com/checkstyle/checkstyle/wiki/How-to-generate-Checkstyle-report-for-Google-Guava-project

Few XPATH conditions for query:
http://stackoverflow.com/questions/28370054/find-a-specific-groupid-from-a-maven-pom-xml-using-xmstarlet


Useful command to print all tags from xml file to help construct XPATH:
xmlstarlet el -v pom.xml

Extract certain tag with inner tags from huge XML

Task: You have huge XML file (300 Mb), you need to get out(filter out/extract/grab) it only one tag with specific value.

Under Ubuntu 12.04 install xslt processor:

sudo apt-get install xsltproc

Structure of huge XML (hugeFile.xml):

<?xml version="1.0" encoding="ISO-8859-1"?>
<Feed ExtractDate="07/25/2013" ExtractTime="15:30:15">

  ..... a lot of companies information
<COMPANY ... LegalName="MyCompany" .....>

     ..... a lot of inner tags .....

  </COMPANY>

 ..... a lot of companies information

</Feed>

 

Create extract.xsl file:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="/">

<xsl:element name="TagToExtract">
   <xsl:apply-templates select="//COMPANY[@LegalName='MyCompany']" />
</xsl:element>

 </xsl:template>
  <xsl:template match="//COMPANY[@LegalName='MyCompany']">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()" />
    </xsl:copy>
  </xsl:template>
  <xsl:template match="@*|node()">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()" />
    </xsl:copy>
  </xsl:template>
</xsl:stylesheet>

Execute XSLT processor (12 seconds):

xsltproc extract.xsl hugeFile.xml > 1.xml