Small rsync script to copy media from a library to another library

syncmedialib.sh

#!/usr/bin/env bash

# Configure common information
LIBRARIES=("Filme" "Serien" "Musik")

#########################
# Argument: Destination #
#########################

# Ceck if there is an argument
if [ -n "$1" ]; then
    # Use the argument as the destination
    DESTINATION="$1"
else
    # Read the destination from user input
    read -ep "Please enther the destination library's path: " DESTINATION
fi

###################################
# Optional Argument: Sources list #
###################################

SOURCES_LIST=""
if [ -n "$2" ]; then
    if [ -f "$2" ]; then
        SOURCES_LIST="$2"
    else
        echo "The provided list '$2' does not exist or is not a file."
        exit 1
    fi
fi

###########
# Sources #
###########

# Inform the user on how to enter sources
echo "Enter the individual paths you want to synchronize to the destination library ($DESTINATION)."
echo "Use ENTER to confirm the entered path. Enter an empty path to begin the synchronization."

# Collect the sources provided by user input
SOURCES=()
if [ -n "$SOURCES_LIST" ]; then
    # Read paths from file
    while IFS= read -r LINE || [ -n "$LINE" ]; do
        # Skip empty lines or lines starting with #
        [[ -z "$LINE" || "$LINE" =~ ^# ]] && continue
        if [ ! -e "$LINE" ]; then
            echo "Warning: The path in file does not exist: $LINE"
        else
            SOURCES+=("$LINE")
        fi
    done < "$SOURCES_LIST"
else
    while true; do
        read -ep "Path: " SOURCE
        if [ -z "$SOURCE" ]; then
            break
        fi
        if [ ! -e "$SOURCE" ]; then
            echo "The provided path does not exist: $SOURCE"
        else
            SOURCES+=("$SOURCE")
        fi
    done
fi

# Ensure that any sources have been provided
if [ ${#SOURCES[@]} -eq 0 ]; then
    echo "No paths have been provided, exiting."
    exit 1
fi

##########################
# Common relative parent #
##########################

# Create a temporary directory without leaving the filesystem
TMP_DIR=$(mktemp -d)

# Link the provided sources to the temporary directory
for SOURCE in "${SOURCES[@]}"; do
    for LIBRARY in "${LIBRARIES[@]}"; do
        # Check if the source is within the current library
        if [[ "$SOURCE" == *"/$LIBRARY/"* ]]; then
            # Extract the relative path starting from the library (e.g., Filme/Alien/Alien 1)
            RELATIVE_PATH="${SOURCE#*"/$LIBRARY/"}"
            RELATIVE_PATH="$LIBRARY/$RELATIVE_PATH"

            # Create the necessary directories in the temp directory
            mkdir -p "$TMP_DIR/$(dirname "$RELATIVE_PATH")"
            
            # Create a symbolic link to the source in the temp directory
            ln -s "$SOURCE" "$TMP_DIR/$RELATIVE_PATH"
            break
        fi
    done
done

###############
# Synchronize #
###############

# Initialize the rsync arguments list
ARGS=()

# Functionality
ARGS+=("--relative")         # Use relative paths to keep path structure
ARGS+=("--recursive")        # Sync provided sources recursively
ARGS+=("--no-inc-recursive") # Recurse before starting sync to prevent invalid / incrementing estimates in the output
ARGS+=("--copy-links")       # Sync the symlinks in TMP_DIR as regular folders / files
ARGS+=("--times")            # Set modified time to prevent unecessary writes in case nothing changed

# Configure the output
ARGS+=("--verbose")         # Use verbose output
ARGS+=("--info=progress2")  # Show progress of the sync operation
ARGS+=("--info=name0")

# Dry run rsync to show the changes to be made by the sync
rsync "${ARGS[@]}" --dry-run --itemize-changes "$TMP_DIR/" "$DESTINATION"

# Ask the user to confirm the changes
if read -rp "Do you want to proceed with the changes above? (y/n): " ANSWER && [[ "$ANSWER" =~ ^[Yy]$ ]]; then
    # Run the final rsync command to sync
    rsync "${ARGS[@]}" "$TMP_DIR/" "$DESTINATION"
else
    echo "Cancelled synchronization."
fi

###########
# Cleanup #
###########

# Remove the temporary directory
rm -rf "$TMP_DIR"