latexindent.pl is a perl script to indent (add horizontal leading space to) code within environments, commands, after headings and within special code blocks.

It has the ability to align delimiters in environments and commands, and can modify line breaks.

latexindent.pl, version 3.17.1, 2022-04-04

Chris Hughes (cmhughes)

A simple example follows; there are many more features available, detailed in full within the documentation.

Before:

\begin{one}
latexindent.pl adds leading
space to code blocks.
\begin{two}
It aims to beautify .tex, .sty
and .cls files. It is customisable
via its YAML interface.
\end{two}
\end{one}

After running

latexindent.pl myfile.tex

then you receive:

\begin{one}
	latexindent.pl adds leading
	space to code blocks.
	\begin{two}
		It aims to beautify .tex, .sty
		and .cls files. It is customisable
		via its YAML interface.
	\end{two}
\end{one}

For complete details, please see:

• pdf: http://mirrors.ctan.org/support/latexindent/documentation/latexindent.pdf
• online: http://latexindentpl.readthedocs.io/ (if you find discrepancies between the pdf and readthedocs, defer to the pdf)

I use both travis-ci (Linux) and AppVeyor (Windows) as continuous integration services to test latexindent.pl for a small selection of test cases for every commit (I use git to track changes in the many test cases listed in the test-cases directory); you can see which versions of perl are tested by travis-ci within .travis.yml. Additionally, GitHub actions performs checks on a selection of test cases on every commit.

latexindent.pl
LatexIndent/*.pm
defaultSettings.yaml

latexindent.exe
defaultSettings.yaml

conda install latexindent.pl -c conda-forge

latexindent.exe is created and released by GitHub Actions; the file that controls this is available within the github/workflows directory of this repository, and you can track the actions on the actions page of this repository.

You can use latexindent with the pre-commit framework by adding this to your .pre-commit-config.yaml:

  - repo: https://github.com/cmhughes/latexindent.pl.git
    rev: V3.17.1
    hooks:
      - id: latexindent

You can add a .latexindent.yaml to the root of the git repo to customize the behavior.

A nice way to test the script is to navigate to the test-cases directory, and then run the command (on Linux/Mac -- sorry, a Windows test-case version is not available):

./test-cases.sh

This script may not work for your style of formatting; I highly recommend comparing the outputfile.tex to make sure that nothing has been changed (or removed) in a way that will damage your file.

I recommend using each of the following:

• a visual check, at the very least, make sure that each file has the same number of lines
• a check using latexdiff inputfile.tex outputfile.tex
• git status myfile.tex

I'm happy to review feature requests, but I make no promises as to if they will be implemented; if they can be implemented, I make no promises as to how long it will take to implement them, and in which order I do so -- some features are more difficult than others! Feel free to post on the issues page of this repository, but please do use the given issue template!

I follow the development model given here: http://nvie.com/posts/a-successful-git-branching-model/ which means that latexindent.pl always has (at least) two branches:

main
develop

The main branch always contains the released version and develop contains the development version. When developing a new feature or bug fix, I typically use:

git checkout develop
git checkout -b feature/name-of-feature

and then I merge it into the develop branch using

git checkout develop
git merge feature/name-of-feature --no-ff

I develop latexindent.pl on Ubuntu Linux, using perlbrew; I currently develop on perl version v5.34.1

You might like to checkout the following related projects on github.

arara:

atom-beautify:

LaTeX-Workshop:

Neelfrost/dotfiles:

Thank you to the contributors to the project!

I find that the following quotes resonate with me with regards to my approach to latexindent.pl:

• I want people to use Perl. I want to be a positive ingredient of the world and make my American history. So, whatever it takes to give away my software and get it used, that's great. Larry Wall
• A common, brute-force approach to parsing documents where newlines are not significant is to read ... the entire file as one string ... and then extract tokens one by one, Christiansen & Torkington, Perl Cookbook, Section 6.16
• Once you understand the power that regular expressions provide, the small amount of work spent learning them will feel trivial indeed Friedl, Mastering Regular Expressions, end of Chapter 1.
• a problem speaks to them, and they have to solve it...and it becomes a hobby. But they keep coming back to it every now and then. They keep tinkering. It will never be finished...that's the point of a hobby, Westwood to Reacher in 'Make Me', Lee Child
• Do the best you can until you know better. Then when you know better, do better. Maya Angelou

changelog.md provides details of the history of the project.