Simple shell script to list files

listfiles.sh

#!/bin/bash

if [[ "$#" -ne 2 ]]; then
    echo "ERROR: Invalid number of arguments" >&2;
    echo >&2;
    echo "Usage: ./listfiles.sh <directory> <outfile>" >&2;
    exit 1;
fi

TARGET_DIR="$1";
OUTPUT_FILE="$2";

if [[ ! -d "$TARGET_DIR" ]]; then
    echo "ERROR: Target is not a directory: $TARGET_DIR" >&2;
    exit 1;
fi

confirm() {
    local prompt="$1";
    local default;
    case "$2" in
        true | True | yes)
            default="True";
            ;;
        false | False | no)
            default="False";
            ;;
        "" | None)
            default="None";
            ;;
        *)
            echo "ERROR: Invalid default \`$2\`" >&2;
            exit 1;
            ;;
    esac
    python3 -c "import sys, rich.prompt; exit(not rich.prompt.Confirm.ask(sys.argv[1], default=$default))" "$prompt";
    return $?;
}

if [[ -f "$OUTPUT_FILE" ]]; then
    echo "WARNING: Output file \`$OUTPUT_FILE\` already exists!";
    echo
    if ! confirm "Do you want to override it?" no; then
        exit 1;
    fi
fi

export ABS_OUTPUT_FILE="$(realpath "$OUTPUT_FILE")"

pushd "$TARGET_DIR" || exit
echo "# List of files in $(pwd) at $(TZ=UTC date +'%F %T')" > "$ABS_OUTPUT_FILE"
fd --strip-cwd-prefix -uuu . | sort >> "$ABS_OUTPUT_FILE"
popd