[Linux] Bash xmlstarlet uso: A command-line XML toolkit

Overview

The xmlstarlet command is a versatile command-line utility for parsing, transforming, and querying XML documents. It allows users to manipulate XML data easily, making it a valuable tool for developers and system administrators working with XML files.

Usage

The basic syntax of the xmlstarlet command is as follows:

xmlstarlet [options] [arguments]

Common Options

• xmlstarlet sel: Selects nodes from an XML document.
• xmlstarlet ed: Edits an XML document.
• xmlstarlet tr: Transforms an XML document using XSLT.
• xmlstarlet val: Validates an XML document against a schema.
• xmlstarlet fo: Formats an XML document for readability.

Common Examples

Selecting Nodes

To select specific nodes from an XML file, you can use the sel option. For example, to select all book elements from a books.xml file:

xmlstarlet sel -t -m "//book" -v "title" -n books.xml

Editing XML

To add a new element to an existing XML document, use the ed option. For instance, to add a new author to a book:

xmlstarlet ed -s "//book" -t elem -n "author" -v "New Author" books.xml

Transforming XML

To transform an XML document using an XSLT stylesheet, use the tr option. Here’s an example:

xmlstarlet tr stylesheet.xsl input.xml > output.xml

Validating XML

To validate an XML file against a schema, use the val option. For example:

xmlstarlet val -e schema.xsd input.xml

Formatting XML

To format an XML file for better readability, use the fo option:

xmlstarlet fo input.xml

Tips

• Always back up your XML files before performing edits, as changes can be irreversible.
• Use the -n option with sel to suppress the output of the selected nodes if you only need to check the existence of nodes.
• Combine multiple options in a single command for more complex operations, such as selecting and transforming XML data in one go.