chdirx

#!/usr/bin/env bash

set -euo pipefail

SCRIPT_NAME=$(basename "$0")
RECURSIVE=false
TARGET_DIR=""

usage() {
	cat <<EOF
Usage: $SCRIPT_NAME [OPTIONS] <directory>

Adds executable permission to scripts in the specified directory. If a file starts with
a shebang (#!), it will be made executable.

Arguments:
  <directory>       The directory to process.

Options:
  -r                Recursively process subdirectories, including hidden ones.
  -h, --help        Show this help message and exit.

Examples:
  $SCRIPT_NAME mydir
  $SCRIPT_NAME -r mydir   # Process subdirectories as well
  $SCRIPT_NAME mydir -r
EOF
	exit "$1"
}

# Parse arguments manually to allow flexible order
while [[ $# -gt 0 ]]; do
	case "$1" in
	-h | --help)
		usage 0
		;;
	-r)
		RECURSIVE=true
		;;
	-*)
		echo "Error: Unknown option '$1'" >&2
		usage 1
		;;
	*)
		if [[ -n $TARGET_DIR ]]; then
			echo "Error: Multiple directories specified: '$TARGET_DIR' and '$1'" >&2
			usage 1
		fi
		TARGET_DIR="$1"
		;;
	esac
	shift
done

# Ensure exactly one directory is provided
if [[ -z $TARGET_DIR ]]; then
	echo "Error: No directory specified." >&2
	usage 1
fi

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

process_directory() {
	local dir="$1"
	# Iterate over both normal and hidden files/directories
	for file in "$dir"/.* "$dir"/*; do
		# Skip if file doesn't exist (handles empty dirs) or if it's `.` or `..`
		[[ -e $file && $file != "$dir/." && $file != "$dir/.." ]] || continue
		# Skip symlinks to prevent loops and operating outside target tree
		[[ -L $file ]] && continue
		if [[ -f $file ]]; then
			# Check if the first line starts with #!
			if head -n 1 "$file" | grep -q '^#!'; then
				chmod +x "$file"
				echo "Added executable permission to: $file"
			fi
		elif [[ -d $file && $RECURSIVE == true ]]; then
			# Recursively process subdirectories
			process_directory "$file"
		fi
	done
}

process_directory "$TARGET_DIR"