ForbCheck (forb)

ForbCheck is a Bash CLI tool designed to analyze a compiled C executable or library and detect the usage of forbidden functions, closely matching how projects are evaluated at 42.

It relies on nm to inspect unresolved symbols and reports exact source locations where forbidden functions are used.

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Key Features

• Deep Analysis: Uses nm and object file scanning (.o) to distinguish between undefined symbols and your own internal functions. No more false positives from your own utils.
• Smart Context Awareness: Automatically detects external libraries like MiniLibX (-mlx) or Math (-lm) to avoid flagging allowed external calls.
• Blazing Fast: Optimized parallel scanning (xargs -P4). Runs in under 0.2s on most projects.
• Stale Binary Detection: Smartly compares source code timestamps with your binary. If you forgot to make re, ForbCheck warns you that results might be outdated.
• Precision Locator: Pinpoints exactly where the forbidden function is called (file and line number).

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🆕 What's New in v1.6.1

Smarter False-Positive Filtering

• Comment Ignoring: ForbCheck is now smart enough to ignore forbidden keywords found in comments (e.g., // TODO: remove printf). It only flags code that actually compiles!

Smart Sync & Cache

• Desync Warning: Modified your .c files but forgot to recompile? The tool now alerts you immediately to prevent testing against an old binary.
• Undo-Friendly: The intelligent cache tracks line counts and file sizes. If you undo changes (Ctrl+Z), the warning resolves itself automatically.

Enhanced CLI Experience

• Hybrid List Command: Use -l to view all authorized functions, or forb -l <func> to quickly check the status of a specific one.
• Global Awareness: Seamlessly switch between projects (e.g., minishell -> cub3d). The tool updates its internal reference context instantly.
• Cleaner Help: A reorganized --help menu for better readability during those late-night coding sessions.

• Optimized: Even on standard school lab machines, the overhead remains negligible, ensuring your workflow is never interrupted.

Requirements

• bash
• nm (GNU binutils)
• grep, awk, sed
• bc (optional, for execution time display)

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Installation

bash -c "$(curl -fsSL https://raw.githubusercontent.com/Mrdolls/forb/refs/heads/main/install.sh)"

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Usage

forb [options] <target> [-f <files...>]

Argument

• <target>: Executable or library to analyze

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Options

General

Option	Description
-h, --help	Display help message
-l, --list [<funcs...>]	Show list or check specific functions
-e, --edit	Edit authorized functions list

Scan Options

Option	Description
-v, --verbose	Show source code context
-f <files...>	Limit analysis to specific files
-p, --full-path	Show full paths
-a, --all	Show authorized functions during scan
--no-auto	Disable automatic library detection

Library Filters

Option	Description
-mlx	Force ignore MiniLibX internal calls
-lm	Force Ignore Math library internal calls

Maintenance

Option	Description
-t, --time	Show execution duration
-up, --update	Update ForbCheck
--remove	Uninstall ForbCheck

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Examples

Basic analysis:

forb minishell (no forbidden fonctions)

Show execution time:

forb -t minishell (with forbidden fonctions)

Limit analysis to specific files:

forb minishell -f heredoc_utils.c

Verbose mode:

forb -v minishell

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Authorized Functions

Authorized functions are defined in:

$HOME/.forb/authorize.txt

Functions may be separated by new lines, spaces, or commas.

Quick edit:

forb -e

Example:

read
write
malloc
free

or

read, write, malloc, free

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Exit Codes

Code	Meaning
0	No forbidden functions detected
1	Forbidden functions detected or error occurred

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Design Philosophy

ForbCheck is designed to be:

• Simple
• Readable
• Useful before project evaluations
• Explicit rather than permissive

It is an assistance tool, not a substitute for understanding project requirements.

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License

Open-source project intended for educational use.

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Author

Mrdolls