A command-line tool that ensures all your text files end with exactly one newline character. This tool helps maintain consistent file formatting across your codebase by automatically adding or removing trailing newlines as needed.
Many POSIX systems expect text files to end with a newline character. Having consistent line endings:
- Prevents spurious diffs in version control
- Ensures proper concatenation of files
- Satisfies POSIX compliance
- Improves readability in terminal environments
- Automatically adds a newline to files that don't end with one
- Removes excess trailing newlines from files that have too many
- Respects
.gitignorepatterns to avoid processing unwanted files - Works with all text file types
- Cross-platform compatibility (Windows, macOS, Linux)
- Dry-run mode to preview changes before applying them
uv add eof-fixerpip install eof-fixerTo fix all files in the current directory and subdirectories:
eof-fixer .To check which files would be modified without making changes:
eof-fixer . --checkThe eof-fixer processes files in the following way:
- Files with no trailing newline: Adds exactly one newline at the end
- Files with exactly one trailing newline: Leaves unchanged
- Files with multiple trailing newlines: Truncates to exactly one newline
- Empty files: Left unchanged
| Original File Content | After Processing |
|---|---|
hello world |
hello world\n |
hello world\n |
hello world\n |
hello world\n\n\n |
hello world\n |
| `` (empty file) | `` (unchanged) |
Note on line endings: when appending a missing terminator, eof-fixer always writes an LF (
\n), regardless of the existing line-ending style of the file. A file that otherwise uses CRLF or CR will end up with a mixed terminator on its last line. This matches the behavior of pre-commit'send-of-file-fixer. Files that already end with a single CRLF, CR, or LF are left untouched.
The tool automatically respects patterns in your .gitignore file, so it won't process files that are ignored by Git. Only the .gitignore at the root of the supplied path is consulted; nested .gitignore files in subdirectories are not read. Additionally, it always ignores:
.gitdirectories.cacheand.uv-cachedirectories (used by uv)- Binary files (detected by null bytes in the first 1024 bytes)
0: No files needed fixing.1: At least one file needed fixing. In--checkmode no changes are written; in the default (fix) mode the files have been rewritten in place. The non-zero exit in fix mode is intentional so the tool can be used as a pre-commit or CI gate — re-run after the fix and the exit code returns to0.
- uv for dependency management
# Clone the repository
git clone https://github.com/modern-python/eof-fixer.git
cd eof-fixer
# Install dependencies
just install# Run tests
just test# Run linting and formatting
just lintContributions are welcome! Please feel free to submit a Pull Request.
- Fork the repository
- Create your feature branch (
git checkout -b feature/AmazingFeature) - Commit your changes (
git commit -m 'Add some amazing feature') - Push to the branch (
git push origin feature/AmazingFeature) - Open a Pull Request
This project is licensed under the MIT License - see the LICENSE file for details.
The core file-fixing logic in this project is derived from the
end-of-file-fixer
hook in pre-commit/pre-commit-hooks,
which is also distributed under the MIT License. This project repackages that
logic as a standalone CLI with .gitignore-aware directory traversal so it can
be used outside of the pre-commit framework.
- pre-commit - A framework for managing and maintaining multi-language pre-commit hooks
- editorconfig - Helps maintain consistent coding styles across different editors and IDEs
Browse the full list of templates and libraries in
modern-python — see the org profile for the
categorized index.