Parsing an XML file and adding a new key based on an existing key

Question

I'm really looking for some advice on the best approach to tackling this in bash.

I have a XML file with 1000's of entries that looks like this:

<?xml version="1.0"?>
<myList>
    <dataitem>
        <path>./5553 Subset 43d.zip</path>
        <name>5553 Subset 43d</name>
    </dataitem>
    <dataitem>
        <path>./Another file name here with spaces.zip</path>
        <name>Another file name here with spaces</name>
    </dataitem>
...

And I'd like to add an additional key to each <dataitem> using the <name> key's data with an mp4 extension, so it would look like this:

<?xml version="1.0"?>
<myList>
    <dataitem>
        <path>./5553 Subset 43d.zip</path>
        <name>5553 Subset 43d</name>
        <video>5553 Subset 43d.mp4</video>
    </dataitem>
    <dataitem>
        <path>./Another file name here with spaces.zip</path>
        <name>Another file name here with spaces</name>
        <video>Another file name here with spaces.mp4</video>
    </dataitem>
...

RomanPerekhrest · Accepted Answer · 2017-12-29 15:28:56Z

2

The right way with xmlstarlet tool:

xmlstarlet ed -s "//dataitem" -t elem -n video input.xml \
| xmlstarlet ed -u "//dataitem/video" -x "concat(./preceding-sibling::name/text(), '.mp4')"

The output should be as:

<?xml version="1.0"?>
<myList>
  <dataitem>
    <path>./5553 Subset 43d.zip</path>
    <name>5553 Subset 43d</name>
    <video>5553 Subset 43d.mp4</video>
  </dataitem>
  <dataitem>
    <path>./Another file name here with spaces.zip</path>
    <name>Another file name here with spaces</name>
    <video>Another file name here with spaces.mp4</video>
  </dataitem>
...

answered Dec 29, 2017 at 15:28

RomanPerekhrest

93.1k4 gold badges75 silver badges112 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

ThatDude Over a year ago

This is such an elegant solution - much appreciated

Parfait · Accepted Answer · 2018-01-01 15:51:47Z

1

Alternatively, consider XSLT, the special-purpose language designed to transform XML, with a bash call to xsltproc.

XSLT (save as .xsl file, a special .xml file)

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" omit-xml-declaration="yes" indent="yes"/>
    <xsl:strip-space elements="*"/>

    <xsl:template match="node()|@*">
     <xsl:copy>
       <xsl:apply-templates select="node()|@*"/>
     </xsl:copy>
    </xsl:template>

    <xsl:template match="dataitem">
     <xsl:copy>
       <xsl:copy-of select="*"/>
       <video><xsl:value-of select="concat(name, '.mp4')"/></video>
     </xsl:copy>
    </xsl:template>

</xsl:stylesheet>

Bash (assuming local cd paths, using installed xsltproc)

xsltproc -o Output.xml XSLTScript.xsl Input.xml

answered Jan 1, 2018 at 15:51

Parfait

108k19 gold badges103 silver badges138 bronze badges

1 Comment

ThatDude Over a year ago

A great solution but a little extravagant for my needs. It's good to see how I might approach this for larger projects though. Thank you

Collectives™ on Stack Overflow

Parsing an XML file and adding a new key based on an existing key

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related