How to pretty print XML from the command line?

Related: https://stackoverflow.com/questions/352098/how-to-pretty-print-json-from-the-command-line

Is there a (unix) shell script to format XML in human-readable form?

Basically, I want it to transform the following:

<root><foo a="b">lorem</foo><bar value="ipsum" /></root>

... into something like this:

<root>
    <foo a="b">lorem</foo>
    <bar value="ipsum" />
</root>

xmllint

This utility comes with libxml2-utils:

echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' |
    xmllint --format -

Perl's XML::Twig

This command comes with XML::Twig [tag:perl] module, sometimes xml-twig-tools package:

echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' |
    xml_pp

xmlstarlet

This command comes with xmlstarlet:

echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' |
    xmlstarlet format --indent-tab

tidy

Check the tidy package:

echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' |
    tidy -xml -i -

Python

Python's xml.dom.minidom can format XML (works also on legacy python2):

echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' |
    python -c 'import sys; import xml.dom.minidom; s=sys.stdin.read(); print(xml.dom.minidom.parseString(s).toprettyxml())'

saxon-lint

You need saxon-lint:

echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' |
    saxon-lint --indent --xpath '/' -

saxon-HE

You need saxon-HE:

 echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' |
    java -cp /usr/share/java/saxon/saxon9he.jar net.sf.saxon.Query \
    -s:- -qs:/ '!indent=yes'

xmllint --format yourxmlfile.xml

xmllint is a command line XML tool and is included in libxml2 (http://xmlsoft.org/).

================================================

Note: If you don't have libxml2 installed you can install it by doing the following:

CentOS

cd /tmp
wget ftp://xmlsoft.org/libxml2/libxml2-2.8.0.tar.gz
tar xzf libxml2-2.8.0.tar.gz
cd libxml2-2.8.0/
./configure
make
sudo make install
cd

Ubuntu

sudo apt-get install libxml2-utils

Cygwin

apt-cyg install libxml2

MacOS

To install this on MacOS with Homebrew just do: brew install libxml2

Git

Also available on Git if you want the code: git clone git://git.gnome.org/libxml2

You can also use tidy, which may need to be installed first (e.g. on Ubuntu: sudo apt-get install tidy).

For this, you would issue something like following:

tidy -xml -i your-file.xml > output.xml

Note: has many additional readability flags, but word-wrap behavior is a bit annoying to untangle (http://tidy.sourceforge.net/docs/quickref.html).

Without installing anything on macOS / most Unix.

Use tidy

cat filename.xml | tidy -xml -iq

Redirecting viewing a file with cat to tidy specifying the file type of xml and to indent while quiet output will suppress error output. JSON also works with -json.

You didn't mention a file, so I assume you want to provide the XML string as standard input on the command line. In that case, do the following:

$ echo '<root><foo a="b">lorem</foo><bar value="ipsum" /></root>' | xmllint --format -

xmllint support formatting in-place:

for f in *.xml; do xmllint -o $f --format $f; done

As Daniel Veillard has written:

> I think > xmllint -o tst.xml --format tst.xml > should be safe as the parser will fully load the input into a tree before opening the output to serialize it.

Indent level is controlled by XMLLINT_INDENT environment variable which is by default 2 spaces. Example how to change indent to 4 spaces:

XMLLINT_INDENT='    '  xmllint -o out.xml --format in.xml

You may have lack with --recover option when you XML documents are broken. Or try weak HTML parser with strict XML output:

xmllint --html --xmlout <in.xml >out.xml

--nsclean, --nonet, --nocdata, --noblanks etc may be useful. Read man page.

apt-get install libxml2-utils
apt-cyg install libxml2
brew install libxml2

This took me forever to find something that works on my mac. Here's what worked for me:

brew install xmlformat
cat unformatted.html | xmlformat

This simple(st) solution doesn't provide indentation, but it is nevertheless much easier on the human eye. Also it allows the xml to be handled more easily by simple tools like grep, head, awk, etc.

Use sed to replace '<' with itself preceeded with a newline.

And as mentioned by Gilles, it's probably not a good idea to use this in production.

# check you are getting more than one line out
sed 's/</\n</g' sample.xml | wc -l

# check the output looks generally ok
sed 's/</\n</g' sample.xml | head

# capture the pretty xml in a different file
sed 's/</\n</g' sample.xml > prettySample.xml

Edit:

Disclaimer: you should usually prefer installing a mature tool like xmllint to do a job like this. XML/HTML can be a horribly mutilated mess. However, there are valid situations where using existing tooling is preferable over manually installing new ones, and where it is also a safe bet the XML's source is valid (enough). I've written this script for one of those cases, but they are rare, so precede with caution.

---

I'd like to add a pure Bash solution, as it is not 'that' difficult to just do it by hand, and sometimes you won't want to install an extra tool to do the job.

#!/bin/bash

declare -i currentIndent=0
declare -i nextIncrement=0
while read -r line ; do
  currentIndent+=$nextIncrement
  nextIncrement=0
  if [[ "$line" == "</"* ]]; then # line contains a closer, just decrease the indent
    currentIndent+=-1
  else
    dirtyStartTag="${line%%>*}"
    dirtyTagName="${dirtyStartTag%% *}"
    tagName="${dirtyTagName//</}"
    # increase indent unless line contains closing tag or closes itself
    if [[ ! "$line" =~ "</$tagName>" && ! "$line" == *"/>"  ]]; then
      nextIncrement+=1
    fi
  fi

  # print with indent
  printf "%*s%s" $(( $currentIndent * 2 )) # print spaces for the indent count
  echo $line
done <<< "$(cat - | sed 's/></>\n</g')" # separate >< with a newline

Paste it in a script file, and pipe in the xml. This assumes the xml is all on one line, and there are no extra spaces anywhere. One could easily add some extra \s* to the regexes to fix that.

I would:

nicholas@mordor:~/flwor$ 
nicholas@mordor:~/flwor$ cat ugly.xml 


<root><foo a="b">lorem</foo><bar value="ipsum" /></root>

nicholas@mordor:~/flwor$ 
nicholas@mordor:~/flwor$ basex
BaseX 9.0.1 [Standalone]
Try 'help' to get more information.
> 
> create database pretty
Database 'pretty' created in 231.32 ms.
> 
> open pretty
Database 'pretty' was opened in 0.05 ms.
> 
> set parser xml
PARSER: xml
> 
> add ugly.xml
Resource(s) added in 161.88 ms.
> 
> xquery .
<root>
  <foo a="b">lorem</foo>
  <bar value="ipsum"/>
</root>
Query executed in 179.04 ms.
> 
> exit
Have fun.
nicholas@mordor:~/flwor$ 

if only because then it's "in" a database, and not "just" a file. Easier to work with, to my mind.

Subscribing to the belief that others have worked this problem out already. If you prefer, no doubt eXist might even be "better" at formatting xml, or as good.

You can always query the data various different ways, of course. I kept it as simple as possible. You can just use a GUI, too, but you specified console.

With [tag:xidel]:

xidel -s input.xml -se . --output-node-format=xml --output-node-indent
<root>
  <foo a="b">lorem</foo>
  <bar value="ipsum"/>
</root>

Or file:write("output.xml",.,{"indent":true()}) to save to a file.