#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <string.h>

typedef struct {
	char *prog;
	char **args;
} command;

command parseInput(char* input);

int main(int argc, char *argv[])
{

	while (1) {

		char input[512]; 	//store input line
		printf("$sshell "); //shell prompt
		fgets(input, 512, stdin); //read line into string
		input[strlen(input) - 1] = '\0';



		//check for exit command
		if (strcmp(input, "exit") == 0) {

			exit(0);

		} else {

			//create new process
			pid_t PID = fork();

			//if child process
			if (PID == 0) {

				int status;
				command comm = parseInput(input);
				status = execvp(comm.prog, comm.args);

				//if exec fails
				if (status != 0) {

					fprintf(stderr, "Error: command not found.\n");
					exit(42);

				//else exit the process
				} else {

					exit(0);

				}

			} else {

				int status;
				wait(&status);
				fprintf(stderr, "+ completed '%s' [%d]\n", input, WEXITSTATUS(status));

			}
		}
	}
	return EXIT_SUCCESS;
}

command parseInput(char *input) {

	command comm;
	int i = 1;
	char *token;

	token = strtok(input, " ");
	//printf("Got a token: %s\n", token);

	comm.prog = (char*) malloc(strlen(token) + 1);
	strcpy(comm.prog, token);

	comm.args = (char**) malloc(sizeof(char*) * 50);

	comm.args[0] = (char*) malloc(strlen(token) + 1);
	strcpy(comm.args[0], token);

	while(1) {
		token = strtok(NULL, " \n");

		if (token == NULL) {
			break;
		}

		comm.args[i] = (char*) malloc(strlen(token) + 1);
		strcpy(comm.args[i], token);
	}
	comm.args[i + 1] = (char*) malloc(sizeof((char*) NULL));
	comm.args[i + 1] = (char*) NULL;

	return comm;
}