rtrim

A high-performance CLI tool for removing trailing whitespace from text files. Built in Rust with a focus on safety, atomicity, and zero external dependencies.

Note: This is a learning project created to study Rust, file system operations, and safe system programming practices.

Features

• Atomic writes - Uses write-sync-rename pattern to prevent data corruption
• Permission preservation - Maintains original file permissions after processing
• Symlink protection - Ignores symlinks to prevent security issues
• Binary file detection - Automatically skips non-UTF-8 files
• Recursive processing - Process entire directory trees
• Zero dependencies - Only uses Rust standard library

Installation

From source

# Clone the repository
git clone https://github.com/raul3k/rtrim.git
cd rtrim

# Build and install
make install

Local installation (no sudo)

PREFIX=~/.local/bin make install

Uninstall

make uninstall

Usage

# Display help
rtrim --help

# Process a single file
rtrim --file path/to/file.txt

# Process a folder recursively
rtrim --folder path/to/folder

How It Works

1. Reads the file content into memory
2. Validates UTF-8 encoding (skips binary files)
3. Removes trailing whitespace from each line
4. Writes to a unique temporary file
5. Syncs to disk (fsync)
6. Atomically renames temp file to original

This ensures that even during a power failure, you won't end up with a corrupted file.

Ignored Directories

When processing folders recursively, the following are automatically skipped:

Category	Directories
Version Control	.git, .svn, .hg
Dependencies	node_modules, target, __pycache__
Virtual Environments	.venv, venv
IDEs	.idea, .vscode
Hidden	Any directory starting with .

Running Tests

cargo test

Project Structure

rtrim/
├── src/
│   └── main.rs      # Main source code with unit tests
├── Cargo.toml       # Rust package manifest
├── Makefile         # Build and install automation
├── LICENSE          # MIT License
└── README.md

Technical Details

• Algorithm complexity: O(N) where N is the file size
• Memory usage: Pre-allocates based on original file size
• Temporary files: Format .{filename}.{pid}.{timestamp}.tmp
• Supported platforms: Unix-like systems (Linux, macOS)

License

MIT License - see LICENSE for details.

Contributing

This project uses Conventional Commits.

Format: <type>(<scope>): <description>

Types: feat, fix, docs, style, refactor, test, chore

Examples:

• feat: add recursive folder processing
• fix(parser): handle empty files
• docs: update installation instructions

Git hooks are automatically configured on the first cargo build.

Learning Topics Covered

This project was built to learn:

• Rust ownership and borrowing
• File system operations in Rust
• Atomic file operations (write-sync-rename pattern)
• Unix file permissions and metadata
• Symlink security considerations
• Unit and integration testing in Rust
• CLI argument parsing without external crates