BibCop is a lightweight, zero-dependency Perl script that patrols your bibliography to ensure quality and consistency.

Unlike biber or bibtex, which check for syntax errors, BibCop checks for manners. It ensures your citations follow specific rules (e.g., “Years must be 4 digits”) and checks the final output for broken data (e.g., ???? or (n.d.)).

Key Features

• Overleaf Native Integration: Uses “Log Injection” to display errors and warnings directly in the Overleaf side panel (Red/Yellow badges).

• Two Modes:

• Source Check (.bib): Validates structure (e.g., “Title must use {} for acronyms”).

• Output Check (.bbl): Validates the generated text (e.g., ensures no ???? or (n.d.) appears in the PDF).

• Universal Support: Works automatically with BibTeX (.aux) and BibLaTeX/Biber (.bcf).

• Zero Dependencies: Written in pure Perl. Runs anywhere latexmk runs.

Installation

1. Add the files

Download bibcop.pl and bibrules.conf (or bblrules.conf) and place them in your project’s root directory (next to main.tex).

2. Update .latexmkrc

Add the following lines to your .latexmkrc file. (Create the file if it doesn’t exist).

# .latexmkrc

# Choose Mode: 'bib' (Default) OR 'bbl'
$BibCopMode = 'bib';

# Load BibCop
do './bibcop.pl';

That’s it! Next time you compile, BibCop will patrol your citations.

Configuration

You can define rules in bibrules.conf (or bblrules.conf). BibCop supports Single-File Configuration: you can write rules for both .bib and .bbl in the same file. The script automatically filters them based on the current mode.

Syntax

Target | Operator | Pattern | Level | Message

• Target: The field name (e.g., year, title). Use entry for BBL checks.
• Operator: missing, ~ (regex match), !~ (regex mismatch), contains.

Example Configuration

# =======================================================================
#  SOURCE RULES (.bib mode)
#  Target: specific fields like 'year', 'title', 'author'
# =======================================================================

# Warn if Title has 2+ consecutive caps (e.g. "IEEE") not protected by {}
title    | ~       | [A-Z]{2,} | WARN  | Title has ALL CAPS. Use { } to protect.

# Error if Year is not exactly 4 digits
year     | !~      | ^\d{4}$   | ERROR | Year must be exactly 4 digits.

# Error if Author is missing
author   | missing | -         | ERROR | Author field is required.

# Warn if DOI contains the URL prefix (style preference)
doi      | contains| http      | WARN  | DOI should not include 'http' prefix.


# =======================================================================
#  OUTPUT RULES (.bbl mode)
#  Target: MUST be 'entry' (checks the rendered citation text)
# =======================================================================

# Error if the output contains placeholder question marks
entry    | contains | ????      | ERROR | Missing data detected (????) in output.

# Error if the date is missing (n.d.)
entry    | contains | (n.d.)    | ERROR | Missing date detected (n.d.).

# Warn if a paper is marked as 'submitted' (if not allowed)
entry    | contains | submitted | WARN  | Paper is marked as 'submitted'.

# Warn if a raw http link is found (should use \url{})
entry    | ~        | http[^s]  | WARN  | Raw http link found. Use \url{} or https.

Modes

You can control what BibCop checks via the $BibCopMode variable in .latexmkrc.

Note: If bblrules.conf is missing in bbl mode, BibCop will NOT fallback to bibrules.conf to avoid confusion. Please ensure the configuration file exists.

Advanced Usage

Custom Rule Filename

You can specify a custom rule file in .latexmkrc. This overrides the default filename.

$BibCheckRules = 'my_lab_rules.conf';
do './bibcop.pl';

License

This script is distributed under the BSD 2-Clause License. See LICENSE.