📸 Bulk Photo Renamer: EXIF datetime → YYYY-MM-DD_HH-MM-SS with dry-run mode

rename_photos.sh

#!/bin/bash

# Photo Rename Script - Renames photos based on EXIF datetime
# Usage: ./rename_photos.sh [directory] [--dry-run]
# 
# Requirements: exiftool (install with: sudo apt install libimage-exiftool-perl)

set -uo pipefail

# Default values
TARGET_DIR="${1:-.}"
DRY_RUN=false
COUNTER=1

# Check for dry-run flag
if [[ "${2:-}" == "--dry-run" ]] || [[ "${1:-}" == "--dry-run" ]]; then
    DRY_RUN=true
    echo "🔍 DRY RUN MODE - No files will be renamed"
    echo
fi

# Color codes for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Function to print colored output
print_status() {
    local color=$1
    local message=$2
    echo -e "${color}${message}${NC}"
}

# Check if exiftool is installed
if ! command -v exiftool &> /dev/null; then
    print_status "$RED" "❌ Error: exiftool is not installed."
    echo "Install it with:"
    echo "  Ubuntu/Debian: sudo apt install libimage-exiftool-perl"
    echo "  macOS: brew install exiftool"
    echo "  Arch: sudo pacman -S perl-image-exiftool"
    exit 1
fi

# Check if target directory exists
if [[ ! -d "$TARGET_DIR" ]]; then
    print_status "$RED" "❌ Error: Directory '$TARGET_DIR' does not exist."
    exit 1
fi

print_status "$BLUE" "📸 Photo Renaming Script"
print_status "$BLUE" "Directory: $TARGET_DIR"
echo

# Supported image extensions
EXTENSIONS=("jpg" "jpeg" "png" "tiff" "tif" "raw" "cr2" "nef" "arw" "dng" "heic" "webp")

# Build find command with all extensions
FIND_PATTERN=""
for ext in "${EXTENSIONS[@]}"; do
    if [[ -n "$FIND_PATTERN" ]]; then
        FIND_PATTERN="$FIND_PATTERN -o"
    fi
    FIND_PATTERN="$FIND_PATTERN -iname \"*.$ext\""
done

# Count total files first
TOTAL_FILES=$(eval "find \"$TARGET_DIR\" -type f \\( $FIND_PATTERN \\)" | wc -l)
print_status "$BLUE" "Found $TOTAL_FILES image files to process"
echo

# Initialize counters
RENAMED=0
SKIPPED=0
ERRORS=0

# Function to generate safe filename
generate_safe_filename() {
    local datetime="$1"
    local extension="$2"
    local base_name="$3"
    local dir="$4"
    
    # Convert datetime to filename format: YYYY-MM-DD_HH-MM-SS
    local formatted_date=$(echo "$datetime" | sed 's/[: ]/_/g' | sed 's/__/_/g')
    local new_name="${formatted_date}.${extension}"
    local full_path="${dir}/${new_name}"
    
    # If file exists, add counter
    local counter=1
    while [[ -e "$full_path" ]]; do
        new_name="${formatted_date}_${counter}.${extension}"
        full_path="${dir}/${new_name}"
        ((counter++))
    done
    
    echo "$new_name"
}

# Function to process a single file
process_file() {
    local filepath="$1"
    local filename=$(basename "$filepath")
    local dirname=$(dirname "$filepath")
    local extension="${filename##*.}"
    
    printf "[$COUNTER/$TOTAL_FILES] Processing: %s... " "$filename"
    
    # Extract datetime from EXIF data
    local datetime=$(exiftool -s3 -DateTimeOriginal -CreateDate -d "%Y-%m-%d %H:%M:%S" "$filepath" 2>/dev/null | head -n1)
    
    if [[ -z "$datetime" || "$datetime" == "-" ]]; then
        print_status "$YELLOW" "⚠️  No datetime found, skipping"
        SKIPPED=$((SKIPPED + 1))
        return 0
    fi
    
    # Generate new filename
    local new_name=$(generate_safe_filename "$datetime" "$extension" "$filename" "$dirname")
    local new_path="${dirname}/${new_name}"
    
    # Check if rename is needed
    if [[ "$filename" == "$new_name" ]]; then
        print_status "$BLUE" "✓ Already correctly named"
        SKIPPED=$((SKIPPED + 1))
        return 0
    fi
    
    # Perform rename
    if [[ "$DRY_RUN" == true ]]; then
        print_status "$GREEN" "📝 Would rename to: $new_name"
        RENAMED=$((RENAMED + 1))
    else
        if mv "$filepath" "$new_path" 2>/dev/null; then
            print_status "$GREEN" "✅ Renamed to: $new_name"
            RENAMED=$((RENAMED + 1))
        else
            print_status "$RED" "❌ Failed to rename"
            ERRORS=$((ERRORS + 1))
            return 0
        fi
    fi
    
    return 0
}

# Process all image files
while IFS= read -r -d '' file; do
    process_file "$file"
    COUNTER=$((COUNTER + 1))
done < <(eval "find \"$TARGET_DIR\" -type f \\( $FIND_PATTERN \\) -print0")

# Print summary
echo
print_status "$BLUE" "📊 Summary:"
if [[ "$DRY_RUN" == true ]]; then
    echo "  Files that would be renamed: $RENAMED"
else
    echo "  Files renamed: $RENAMED"
fi
echo "  Files skipped: $SKIPPED"
echo "  Errors: $ERRORS"
echo "  Total processed: $TOTAL_FILES"

if [[ "$DRY_RUN" == true ]]; then
    echo
    print_status "$YELLOW" "💡 Run without --dry-run to actually rename files"
fi

if [[ $ERRORS -gt 0 ]]; then
    exit 1
fi