Problema 4 da ficha 5

ex04.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#define MAXSIZE 1024
#define READ 0
#define WRITE 1

int main(int argc, char *argv[]){
	char lsCommand[256];
	char grepCommand[256];
	int p[2];
	int j[2];

	pid_t pid = 0;

	pipe(p);
	pipe(j);

	if(argc != 3){
		printf("Usage: %s [ls argument] [grep argument]\n",argv[0]);
		exit(1);
	}

	pid = fork();
	if(pid == 0){
		close(p[READ]);
		dup2(p[WRITE],STDOUT_FILENO);

		execlp("ls","ls","-laR",argv[1],NULL);
		perror("erro");
	}else if(pid > 0){
		pid = fork();
		if(pid == 0){
			close(j[READ]);
			dup2(j[WRITE],STDOUT_FILENO);
			close(p[WRITE]);
			dup2(p[READ],STDIN_FILENO);

			execlp("grep","grep",argv[2],NULL);
			perror("erro");
		}else{
			close(p[WRITE]);
			close(p[WRITE]);
			close(j[WRITE]);
			dup2(j[READ],STDIN_FILENO);

			execlp("sort","sort",NULL);
			perror("erro");			
		}
	}

	return 0;
}