git-llm: automatically create commit messages. powered by `llm` by simon willison

git-llm.zsh

#!/bin/zsh
# -----------------------------------------------------------------------------
# the `llm` CLI util is awesome, can get it here: https://llm.datasette.io/en/stable/

generate_commit_message() {
    # Get last 3 commit messages
    last_commits=$(git log -3 --pretty=format:"- %s" 2>/dev/null)
    
    git diff --cached | llm "
    Below is a diff of all staged changes, coming from the command:
    \`\`\`
    git diff --cached
    \`\`\`

    For context, here are the last 3 commit messages:
    $last_commits

    Please generate a concise, one-line commit message for these changes that follows a similar style to the previous commits.

    you can include thoughts, but make sure you prefix with # as comments for the editor.
    
    start your response with # Analysis:
    "
}

gcm() {
    # Main script
    temp_output=$(mktemp)

    # Check if there are any staged changes
    if [ -z "$(git diff --cached)" ]; then
        echo "No staged changes."
        return 1
    fi


    echo -n "\x1b[2m"
    echo "thinking..."
    generate_commit_message | tee "$temp_output"
    # can insert awk '{ print $0; fflush(); }' before tee to get line-by-line output 
    # instead of token-by-token output, if you prefer.
    
    echo -n "\x1b[0m"

    commit_message=$(tail -n 1 "$temp_output")
    rm "$temp_output"

    # Create a temporary file for the commit message
    temp_file=$(mktemp)
    echo "$commit_message" > "$temp_file"

    # Open the default git editor
    if git config --get core.editor > /dev/null 2>&1; then
        # Use git's configured editor
        $(git config --get core.editor) "$temp_file"
    else
        # Fallback to default editor
        ${VISUAL:-${EDITOR:-vi}} "$temp_file"
    fi

    # Read the edited message
    edited_message=$(cat "$temp_file")
    rm "$temp_file"  # Clean up

    # Check if the message is empty (user aborted)
    if [ -z "$edited_message" ]; then
        echo "Commit cancelled."
        return 1
    fi

    # Commit with the edited message
    if git commit -m "$edited_message"; then
        echo "Changes committed successfully!"
        return 0
    else
        echo "Commit failed. Please check your changes and try again."
        return 1
    fi
}

gcm