Git Diff

A command-line utility to visually compare changes between two Git revisions using the Meld diff tool.
This script automates the extraction of changed files from specified Git revisions, saves them to temporary directories, and launches Meld for side-by-side comparison.

Features

• Visual Diff: Compares two Git revisions using Meld (can be changed on tool that can compare two folders).
• Customizable: Supports custom paths for Meld, repository, revisions, and log directory.
• Automatic Extraction: Extracts only changed files between revisions.
• Symbolic Linking: Uses symbolic links for current HEAD files for efficiency.
• Logging: Flexible logging options and error handling.

Requirements

• Python 3.x
• Meld installed and available in your system path
• logger.py (custom logging module included or provided separately)
• Git installed and available in your system path

Installation

1. Clone the repository or copy the script files:

   git clone <your-repo-url>
   cd <your-repo-directory>

2. Ensure logger.py is present in the same directory as the script.
3. Install Meld (if not already installed):
   • On Ubuntu/Debian: sudo apt-get install meld
   • On macOS: brew install meld
   • On Windows: Download Meld

Usage

python git_meld_diff.py [options] [rev_old] [rev_new]

Options

Option	Description	Default Value
--meld-exec	Path to Meld executable	meld
--dir-repo	Path to the git repository	Current directory
--dir-old	Directory for older revision files	/home/user/temp/compare/old
--dir-new	Directory for newer revision files	/home/user/temp/compare/new
--log-dir	Directory to save logs	(not set)
--rev-old	Older git revision	HEAD^
--rev-new	Newer git revision	HEAD
--log-level	Logging level (debug, info, etc.)	debug

Examples

• Compare the last commit with the current state:

  python git_meld_diff.py

• Compare two specific revisions:

  python git_meld_diff.py --rev-old abc123 --rev-new def456

• Specify a custom Meld path and log directory:

  python git_meld_diff.py --meld-exec /usr/bin/meld --log-dir /tmp/logs

How It Works

1. Parses command-line arguments.
2. Identifies changed files between two Git revisions.
3. Extracts file contents for each revision into separate directories.
4. Launches Meld to visually compare the directories.

Troubleshooting

• Meld not found: Ensure Meld is installed and the path is correct.
• logger.py missing: Make sure logger.py is present in the script directory.
• Permission issues: Run the script with appropriate permissions to create directories and files.

Other

Helpfull Git Aliases

[alias]
	s = status
	b = branch
	bn = rev-parse --abrev-ref HEAD

	### top n commits in currents branch
	l = log --pretty=format:'%Cred%h%Creset %Cgreen%ad%Creset  %s %C(cyan)<%an>%Creset%C(auto)%d%C(reset)' --abbrev-commit --date=format:'%Y%m%d %H:%M' -15
	lt = log --graph --abbrev-commit --pretty=format:'%C(bold blue)%h%C(reset) - %C(cyan)%ad%C(reset) %C(dim white)%cn <%ce>%C(reset)%C(auto)%d%C(reset)\n\t\t%C(white)%s%C(reset)' --date=format:'%Y%m%d %H:%M' -15
	lg = log --pretty=format:'%Cred%h%Creset - %s %C(auto)%d%C(reset)  %Cgreen(%ad) %C(cyan)<%an>%Creset' --abbrev-commit --date=short
	lgt = log --graph --abbrev-commit --decorate --format=format:'%C(bold blue)%h%C(reset) - %C(auto)%d%C(reset) %C(cyan)%ad%C(reset) %C(dim white)%cn <%ce>%C(reset)\n\t\t%C(white)%s%C(reset)' --date=format:'%Y%m%d %H:%M'

	# show files
	sf = diff-tree --name-only -r
	df = !"python /home/user/projects/utils_py/git_diff.py"

License

This project is licensed under the GNU General Public License v3.0.

Author

Andrii Dov. andridov@gmail.com