argparser.sh

#!/bin/bash
# Argument parse

function parse_args() {
	local _i __i _argument _nextargument
	local count=0

	#scope only func
	#parse long args
	function parse_long() {
		local _arg _nextarg _name _value _i

		#strip --
		_arg=${1#--}
		_nextarg=$2
		#strip after =
		_name="${_arg%%=*}"
		#if arg contains =
		if [[ $_arg == *=* ]]; then
			#strip before =
			_value="${_arg#*=}"

			#if next argument doesnt contain a dash it means it's the value
		elif [[ ! $_nextarg == -* ]]; then
			_value="$_nextarg"
		else
			_value=true
		fi

		#convert dash to camelcase
		if [[ $_name =~ "-" ]]; then
			_name=$(echo "$_name" | awk -F"-" '{for(i=2;i<=NF;i++){$i=toupper(substr($i,1,1)) substr($i,2)}} 1' OFS="")
		fi

		eval "$_name=\$_value"

		#set short if mapping is defined
		if [[ "${ARGPARSER_MAP[@]}" =~ "$_name" ]]; then
			for _i in "${!ARGPARSER_MAP[@]}"; do
				if [[ ${ARGPARSER_MAP[${_i}]} == "$_name" ]]; then
					_name=$ARGPARSER_SHORT_PREFIX$_i
					eval "$_name"=true
				fi
			done
		fi
	}

	#parse short args
	function parse_short() {
		local _i _arg _name _letter

		#strip -
		_arg=${1#-}

		#for each char
		for _i in $(seq 1 ${#_arg}); do
			_letter=${_arg:_i-1:1}
			_name=$ARGPARSER_SHORT_PREFIX$_letter
			eval "$_name"=true

			#set long if mapping is defined
			if [[ ${ARGPARSER_MAP[${_letter}]} ]]; then
				_name=${ARGPARSER_MAP[${_letter}]}
				eval "$_name"=true
			fi
		done
	}

	#parse argument
	function parse_argument() {
		local _name _value

		_name="$ARGPARSER_ARGUMENT_PREFIX$count"
		# shellcheck disable=SC2034
		_value=$1

		eval "$_name=\$_value"
	}

	#default short prefix if not configured
	[ -z "$ARGPARSER_SHORT_PREFIX" ] && ARGPARSER_SHORT_PREFIX="opt"

	#default argument prefix if not configured
	[ -z "$ARGPARSER_ARGUMENT_PREFIX" ] && ARGPARSER_ARGUMENT_PREFIX="argument"

	#init all short opt to false
	for _i in {{a..z},{A..Z}}; do
		_name=$ARGPARSER_SHORT_PREFIX$_i
		eval $_name=false
	done

	allargs=("$@")
	__i=0

	#analyze args
	for _i in "${!allargs[@]}"; do
		_argument=${allargs[$__i]}
		_nextargument=${allargs[$__i + 1]}

		case $_argument in
		--*)
			parse_long "$_argument" "$_nextargument"
			#skip next arg
			[[ ! $_nextargument == -* ]] && ((__i++))
			;;
		-*)
			parse_short "$_argument"
			;;
		*)
			((count++))
			parse_argument "$_argument"
			;;
		esac

		((__i++))
	done
}