//
//  myCLI.swift
//  CLI
//
//  Created by Carlisle Miller on 6/03/2017.
//
// This program attempts to replicate the command line interface. It takes commands from the user
// and prints the output to the terminal. It loops until the user enters 'exit'.


import Foundation

private func WEXITSTATUS(_ status: CInt) -> CInt
{
	return (status >> 8) & 0xff
}

while (true) {
	let cmd: String = readLine()! // Reads command from user

	if (cmd == "exit") {
		exit(EXIT_SUCCESS)
	}

	var splitArray = cmd.components(separatedBy: " ") // Splits users string up into an array when a space is detected
	var cargv = splitArray.map { strdup($0) }
	cargv.append(nil)

	defer {
		for arg in cargv { free(arg) }
	}

	var pid = pid_t()
	let r: Int32 = posix_spawnp(&pid, splitArray[0], nil, nil, cargv, nil) // posix_spawnp creates new process and executes a commandq

	if(r != 0) {
		let err: String = String(cString: strerror(r))
		print("posix_spawnp failed with: \(err)")
		exit(EXIT_FAILURE)
	}

	var status: Int32 = 0
	let rv = waitpid(pid, &status, 0)
	if rv != -1 {
		print("Exit status: \(WEXITSTATUS(status))")
	}
}