Count git changed and deleted lines in the working tree or in the staged files

chgcount.sh

#!/bin/bash

# chgcount.sh - Count lines added/modified and deleted in git diff
#
# Usage: chgcount.sh [OPTIONS]
#
# Options:
#   -p, --pattern PATTERN    File pattern to check (default: all files)
#                            Use **/ prefix for recursive matching in subdirectories
#   -f, --files FILES        Explicit space-separated list of files to check
#   -s, --staged             Look into staged files (default: unstaged)
#   -b, --branch BRANCH      Compare against branch (default: current working tree)
#   -d, --details            Show detailed per-file statistics
#   -h, --help               Show this help message
#
# Pattern Examples:
#   "*.php"                  Matches PHP files in current directory only
#   "**/*.php"               Matches PHP files recursively in all subdirectories
#   "**/Rest*.php"           Matches Rest*.php files anywhere in the tree
#   "src/**/*.php"           Matches PHP files only under src/ directory
#
# Usage Examples:
#   chgcount.sh                           # Count unstaged changes
#   chgcount.sh -s                        # Count staged changes
#   chgcount.sh -p "**/*.php"             # Count all PHP files recursively
#   chgcount.sh -p "**/Rest*.php"         # Count Rest*.php files anywhere
#   chgcount.sh -f "file1.php file2.php"  # Count specific files only
#   chgcount.sh -b trunk                  # Compare current branch against trunk
#   chgcount.sh -b trunk -p "**/*.php" -d # PHP files vs trunk with details

set -e

# Default values
PATTERN=""
FILE_LIST=""
STAGED=false
BRANCH=""
DETAILS=false

# Parse arguments
while [[ $# -gt 0 ]]; do
    case $1 in
        -p|--pattern)
            PATTERN="$2"
            shift 2
            ;;
        -f|--files)
            FILE_LIST="$2"
            shift 2
            ;;
        -s|--staged)
            STAGED=true
            shift
            ;;
        -b|--branch)
            BRANCH="$2"
            shift 2
            ;;
        -d|--details)
            DETAILS=true
            shift
            ;;
        -h|--help)
            sed -n '/^# chgcount.sh/,/^$/p' "$0" | sed 's/^# \?//' | sed '/^$/d'
            exit 0
            ;;
        *)
            echo "Unknown option: $1"
            echo "Use -h or --help for usage information"
            exit 1
            ;;
    esac
done

# Check if we're in a git repository
if ! git rev-parse --git-dir > /dev/null 2>&1; then
    echo "Error: Not a git repository"
    exit 1
fi

# Validate that pattern and files are not both specified
if [ -n "$PATTERN" ] && [ -n "$FILE_LIST" ]; then
    echo "Error: Cannot use both --pattern and --files options together"
    exit 1
fi

# Build git diff command
GIT_CMD="git diff --numstat"

if [ "$STAGED" = true ]; then
    GIT_CMD="$GIT_CMD --staged"
fi

if [ -n "$BRANCH" ]; then
    GIT_CMD="$GIT_CMD $BRANCH"
fi

if [ -n "$PATTERN" ]; then
    GIT_CMD="$GIT_CMD -- $PATTERN"
elif [ -n "$FILE_LIST" ]; then
    GIT_CMD="$GIT_CMD -- $FILE_LIST"
fi

# Get the diff stats
DIFF_OUTPUT=$($GIT_CMD)

if [ -z "$DIFF_OUTPUT" ]; then
    if [ "$STAGED" = true ]; then
        echo "No staged changes found."
    else
        echo "No changes found in working tree."
    fi
    echo "Run with -h for more options"
    exit 0
fi

# Parse the output and sum up the changes
ADDED=0
DELETED=0
FILES=0
declare -a FILE_DETAILS

while IFS=$'\t' read -r add del file; do
    # Skip binary files (marked with -)
    if [ "$add" = "-" ] || [ "$del" = "-" ]; then
        continue
    fi

    ADDED=$((ADDED + add))
    DELETED=$((DELETED + del))
    FILES=$((FILES + 1))

    # Store details for later if needed
    if [ "$DETAILS" = true ]; then
        FILE_DETAILS+=("$add|$del|$file")
    fi
done <<< "$DIFF_OUTPUT"

# Check if run without arguments
NO_ARGS=false
if [ "$STAGED" = false ] && [ -z "$BRANCH" ] && [ -z "$PATTERN" ] && [ -z "$FILE_LIST" ]; then
    NO_ARGS=true
fi

# Print results
echo "========================"
echo "Git Diff Statistics"
echo "========================"

if [ "$STAGED" = true ]; then
    echo "Mode: Staged changes"
else
    echo "Mode: Unstaged changes"
fi

CURRENT_BRANCH=$(git rev-parse --abbrev-ref HEAD)
if [ -n "$BRANCH" ]; then
    if [ "$STAGED" = true ]; then
        echo "Comparing: staged changes in $CURRENT_BRANCH vs $BRANCH"
    else
        echo "Comparing: working tree changes in $CURRENT_BRANCH vs $BRANCH"
    fi
else
    if [ "$STAGED" = true ]; then
        echo "Comparing: staged changes vs $CURRENT_BRANCH"
    else
        echo "Comparing: working tree changes vs $CURRENT_BRANCH"
    fi
fi

if [ -n "$PATTERN" ]; then
    echo "Pattern: $PATTERN"
elif [ -n "$FILE_LIST" ]; then
    echo "Files: $FILE_LIST"
fi

echo "------------------------"
echo "Files changed: $FILES"
echo "Lines added/modified: $ADDED"
echo "Lines deleted: $DELETED"
echo "Net change: $((ADDED - DELETED))"
echo "========================"

# Show detailed breakdown if requested
if [ "$DETAILS" = true ] && [ ${#FILE_DETAILS[@]} -gt 0 ]; then
    echo ""
    echo "Per-file breakdown:"
    echo "------------------------"
    printf "%-10s %-10s %-10s %s\n" "Added" "Deleted" "Net" "File"
    printf "%-10s %-10s %-10s %s\n" "------" "-------" "---" "----"

    for entry in "${FILE_DETAILS[@]}"; do
        IFS='|' read -r add del file <<< "$entry"
        net=$((add - del))
        printf "%-10s %-10s %-10s %s\n" "$add" "$del" "$net" "$file"
    done
    echo "========================"
fi

if [ "$NO_ARGS" = true ]; then
    echo ""
    echo "Run with -h for more options"
fi