#!/bin/bash
usuarios="/etc/passwd"
id=$(id -u)
if [ "$id" != "0" ]
then
	echo "Este script necesita privilegios de administracion"
	exit 1
fi

if [ $# -ne 2 ]
then
	echo "Numero incorrecto de parametros"
elif [ $1 = "-a" ]
then
	while read -r line
	do
		user=$(echo "$line" | cut -d "," -f 1)
		pass=$(echo "$line" | cut -d "," -f 2)
		name=$(echo "$line" | cut -d "," -f 3)
		if [ -n "$user" -a -n "$pass" -a -n "$name" ]
		then
			actual=$(grep "^$user:" "$usuarios")
			if [ -n "$actual" ]
			then
				echo "El usuario "$user" ya existe"
			else
				useradd -U -m -k "/etc/skel" -c "$name" -p "$pass" "$user"
				chage -M 30 "$user"
				echo ""$name" ha sido creado."
			fi
		else
			echo "Campo invalido"
			exit 1
		fi
	done > "$2"
elif [ $1 = "-s" ]
then
	while read -r line
	do
		user=$(echo "$line" | cut -d "," -f 1)
		if [ -n "$user" ]
		then
			actual=$(grep "^$user:" "$usuarios")
			if [ -n "$actual" ]
			then
				if [ ! -d "/extra" ]
				then
					mkdir /extra
					if [ ! -d "/extra/backup" ]
					then
						mkdir /extra/backup
					fi
				fi
				if $(tar -cf "$user".tar -C /extra/backup /home/$user)
				then
					userdel -r "$user" > /dev/null 2>&1
					echo ""$user" ha sido borrado."
				fi
			fi
		else
			echo "Campo invalido"
			exit 1
		fi
	done < "$2"
else
	echo "Opcion invalida" >&2
	exit 1
fi