# Bibcop: Style Checker of BibTeX .bib files

![bibcop logo](bibcop-logo.png)

[![l3build](https://github.com/yegor256/bibcop/actions/workflows/l3build.yml/badge.svg)](https://github.com/yegor256/bibcop/actions/workflows/l3build.yml)
[![CTAN](https://img.shields.io/ctan/v/bibcop)](https://ctan.org/pkg/bibcop)
[![License](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/yegor256/bibcop/blob/master/LICENSE.txt)

This LaTeX package checks the quality of your `.bib` file and
emits warning message if any issues are found. You may also like
[biblint](https://github.com/Kingsford-Group/biblint) and
[biblatex-check](https://github.com/pezmc/biblatex-check) tools —
they do _almost_ the same but from the command line.

Read [this blog post][BLOG], in order to understand
the motivation behind this package.

First, [install it][INSTALL] from [CTAN](https://ctan.org/pkg/bibcop)
and then use in the preamble
(if you use [BibTeX](http://www.bibtex.org/), for example):

```tex
\documentclass{article}
\usepackage{bibcop}
\begin{document}
\bibliographystyle{plain}
\bibliography{main}
\end{document}
```

You can also add it as a GitHub Action to your
GitHub repository, with the help of
[bibcop-action](https://github.com/yegor256/bibcop-action).

Otherwise, you can download
[`bibcop.sty`](https://yegor256.github.io/bibcop/bibcop.sty)
and add to your project (together with
[`bibcop.pl`](https://yegor256.github.io/bibcop/bibcop.pl)!).

You can also download
[`bibcop.pl`](https://yegor256.github.io/bibcop/bibcop.pl)
and use it as a command line tool
to check your `.bib` files and to auto-fix them
(you should have [Perl](https://www.perl.org) installed):

```bash
perl bibcop.pl --fix main.bib > fixed.bib
```

This command will read the `main.bib` file and
create `fixed.bib`, which will have the fixed and properly
formatted content (well, to some extent).
Be careful, all comments will be removed.

You can also make changes inline, not creating a new file:

```bash
perl bibcop.pl --fix --in-place main.bib
```

If you install the package using
[`tlmgr`](https://www.tug.org/texlive/tlmgr.html),
you should be able to use `bibcop` directly, without the
necessity to mention Perl:

```bash
tlmgr install bibcop
bibcop --help
```

## How to use as pre-commit hook

If you use [pre-commit], simply add this to your config:

```yaml
-   repo: https://github.com/yegor256/bibcop
    rev: 0.0.31
    hooks:
    -   id: bibcop
        args: []
```

## How to Contribute

If you want to contribute yourself, make a fork, then create a branch,
then run `l3build ctan` in the root directory. It should compile
everything without errors. If not, submit an issue and wait.
Otherwise, make your changes and then run `l3build ctan` again.
If the build is still clean, submit a pull request.

If you want to add a new check, add it as a Perl subroutine
to the `bibcop.pl` file. Don't forget to add a test to one of the test
files that stay in the `perl-tests/` directory.
When ready, run this, in order to check that all tests pass:

```bash
perl tests.pl
```

You should see the `GREAT!` message.

Copyright (c) 2022-2025 Yegor Bugayenko, MIT License

[BLOG]: https://www.yegor256.com/2023/09/05/style-checker-for-bibtex-files.html
[INSTALL]: https://en.wikibooks.org/wiki/LaTeX/Installing_Extra_Packages
[pre-commit]: https://pre-commit.com/
