# latexindent.pl
[](https://github.com/pre-commit/pre-commit)
[](https://ci.appveyor.com/project/cmhughes/latexindent.pl)
[](http://latexindentpl.readthedocs.io/en/latest/)
`latexindent.pl` is a `perl` script to *beautify/tidy/format/indent* (add horizontal leading space to)
code within environments, commands, after headings and within special code blocks.
It has the ability to [align delimiters](https://latexindentpl.readthedocs.io/en/latest/sec-default-user-local.html#aligning-at-delimiters)
in environments and commands, and can [modify line breaks](https://latexindentpl.readthedocs.io/en/latest/sec-the-m-switch.html)
including [text wrapping](https://latexindentpl.readthedocs.io/en/latest/sec-the-m-switch.html#text-wrapping) and
[one-sentence-per-line](https://latexindentpl.readthedocs.io/en/latest/sec-the-m-switch.html#onesentenceperline-modifying-line-breaks-for-sentences).
It can also perform string-based and regex-based
[substitutions/replacements](https://latexindentpl.readthedocs.io/en/latest/sec-replacements.html). The script is customisable through its YAML interface.
It has support for [Conda](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#using-conda), [docker](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#using-docker)
and [pre-commit](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#pre-commit).
## version
latexindent.pl, version 4.0.2, 2026-06-06
## author
Chris Hughes (cmhughes)
## example
Before:
``` tex
\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:
``` tex
\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}
```
tl;dr, a [quick start](https://latexindentpl.readthedocs.io/en/latest/sec-introduction.html#quick-start)
section is available for those short of time.
There are *many* more features available, detailed in full within the [documentation](http://latexindentpl.readthedocs.io/).
## documentation
For complete details, please see:
- pdf: [http://mirrors.ctan.org/support/latexindent/documentation/latexindent.pdf](http://mirrors.ctan.org/support/latexindent/documentation/latexindent.pdf)
- online: [http://latexindentpl.readthedocs.io/](http://latexindentpl.readthedocs.io/) (if you find discrepancies between the pdf and readthedocs, defer to the pdf)
[](http://latexindentpl.readthedocs.io/en/latest)
## getting started
perl users
You'll need
```
latexindent.pl
LatexIndent/*.pm
defaultSettings.yaml
```
in the same directory.
You'll need a few readily-available perl modules. Full details are given within the Appendix
of the [documentation](https://latexindentpl.readthedocs.io/en/latest/);
you might also like to see [.appveyor.yml](.appveyor.yml) for Strawberry perl users.
Windows users without perl
Windows users who do not have a perl installation might prefer to get
latexindent.exe
`latexindent.exe` is a standalone executable file which does not require a `perl` installation.
It is available at [releases](https://github.com/cmhughes/latexindent.pl/releases) page of this repository
and also from [https://ctan.org/tex-archive/support/latexindent](https://ctan.org/tex-archive/support/latexindent).
Linux users
Please see the [Linux section of the appendix](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#linux)
Ubuntu Linux users without perl
Ubuntu Linux users who do not have a perl installation might try the standalone executable
latexindent-linux
which should be saved as simply `latexindent`. It is available at [releases](https://github.com/cmhughes/latexindent.pl/releases) page of this repository
and also from [https://ctan.org/tex-archive/support/latexindent](https://ctan.org/tex-archive/support/latexindent).
Mac users
Please see the [Mac section of the appendix](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#mac)
Mac users without perl
Mac users who do not have a perl installation might try the standalone executable
latexindent-macos
which should be saved as simply `latexindent`. It is available at [releases](https://github.com/cmhughes/latexindent.pl/releases) page of this repository
and also from [https://ctan.org/tex-archive/support/latexindent](https://ctan.org/tex-archive/support/latexindent).
conda users
If you use conda you'll only need
conda install latexindent.pl -c conda-forge
this will install the executable and all its dependencies (including perl) in the activate environment.
You don't even have to worry about `defaultSettings.yaml` as it is included too.
Full details at [using conda](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#using-conda).
**Important**: the executable name is `latexindent.pl` (not `latexindent`).
> [](https://anaconda.org/conda-forge/latexindent.pl)
docker users
If you use latexindent via docker you'll only need
docker pull ghcr.io/cmhughes/latexindent.pl
docker run -v /path/to/local/myfile.tex:/myfile.tex --rm -it ghcr.io/cmhughes/latexindent.pl -s -w myfile.tex
Full details at [using docker](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#using-docker).
In your browser, see [latexindent in zeroperl](https://latexindent-pl.netlify.app/).
## pre-commit
You can use `latexindent` with the [pre-commit
framework](https://pre-commit.com) by adding this to your
`.pre-commit-config.yaml`:
```yaml
- repo: https://github.com/cmhughes/latexindent.pl.git
rev: V4.0.2
hooks:
- id: latexindent
```
Full details at [pre-commit users](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#pre-commit),
including a [worked example](https://latexindentpl.readthedocs.io/en/latest/sec-appendices.html#pre-commit-example-using-l-m-switches)
demonstrating how you can add a `.latexindent.yaml` to the root of the git repo to customize the behavior.
## testing
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
## GitHub codespaces
This repository contains a [vscode devcontainer](https://code.visualstudio.com/docs/devcontainers/containers)
configuration that allows developing and testing with
[GitHub codespaces](https://github.com/features/codespaces) or vscode
devcontainers.
Using GitHub codespaces allows developing in a remote virtual container running
vscode with a preconfigured `perl` installation. You can explore this
by clicking on the `Code` dropdown at the top of this repository, and click
on 'Codespaces'; see the [codespaces details and screenshots](https://github.com/cmhughes/latexindent.pl/issues/442) for more information.
## *important*
This script may not work for your style of formatting; I highly
recommend that when you first use the script you use the `-o` switch
to output to a separate file; something like
```
latexindent.pl myfile.tex -o myfile-output.tex
```
and then check `myfile-output.tex` carefully 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;
* a check using `latexdiff myfile.tex myfile-output.tex`.
I recommend using a version control system to track your files, especially if you intend
to use `latexindent.pl` to modify files.
## feature requests
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*!
## development model
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 align with many of the approaches and details at [Dramatically increase your productivity with Atomic Git Commits](https://suchdevblog.com/lessons/AtomicGitCommits.html).
## perl version
I develop latexindent.pl on Ubuntu Linux, using [perlbrew](https://perlbrew.pl/); I currently develop on perl version v5.42.0
## GitHub Actions
The standalone executables `latexindent.exe`, `latexindent-linux`, `latexindent-macos` are created and released by [GitHub Actions](https://github.com/features/actions); the
file that controls this is available within the [github/workflows](https://github.com/cmhughes/latexindent.pl/tree/main/.github/workflows)
directory of this repository, and you can track the actions on the [actions page](https://github.com/cmhughes/latexindent.pl/actions/) of this repository.
> 
## build status
I use [GitHub actions](https://github.com/cmhughes/latexindent.pl/tree/main/.github/workflows) and `AppVeyor` (Windows) as continuous integration services to test `latexindent.pl`.
I use `git` to track changes in the many test cases listed in the `test-cases` directory.
[](https://ci.appveyor.com/project/cmhughes/latexindent-pl)
## related projects
You might like to checkout the following related projects on github.
[arara](https://github.com/cereda/arara): [](https://github.com/cereda/arara/stargazers)
[atom-beautify](https://github.com/Glavin001/atom-beautify): [](https://github.com/Glavin001/atom-beautify/stargazers)
[LaTeX-Workshop](https://github.com/James-Yu/LaTeX-Workshop): [](https://github.com/James-Yu/LaTeX-Workshop/stargazers)
[Neelfrost/dotfiles](https://github.com/Neelfrost/dotfiles): [](https://github.com/Neelfrost/dotfiles/stargazers)
[latex-formatter](https://github.com/nfode/latex-formatter): [](https://github.com/nfode/latex-formatter)
[latexindent-web](https://github.com/acmiyaguchi/latexindent-web): [](https://github.com/acmiyaguchi/latexindent-web)
## thank you
Thank you to the [contributors](https://github.com/cmhughes/latexindent.pl/graphs/contributors) to the project!
## quotes
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
- *Perl’s primary strength is in text processing. Be it a regex-based approach or otherwise, Perl is excellent for logfile analysis, text manipulation, in-place editing of files, and scouring structured text files for specific field values*,
Girish Venkatachalam [Why Perl is still relevant in 2022](https://stackoverflow.blog/2022/07/06/why-perl-is-still-relevant-in-2022/)
- *Do the best you can until you know better. Then when you know better, do better.* Maya Angelou
- *Gwneuwch y pethau bychain, do the little things*, Dewi Sant
- *We are our mistakes. Sometimes they are the best part of us*. Harlen Coben, Think Twice
- *Formatting. Indentation. Style. Code layout. Whatever you choose to call it, it's one of the most contentious aspects of programming discipline.* Damian Conway, Perl Best Practices, chapter 2.
- *If you're not making mistakes, then you're not doing anything*, John Woodern
## changelog
[changelog.md](documentation/changelog.md) provides details of the history of the project.