프로세스 생성 실습3 fork() exec() wait()

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



int main()
{
	int pid;
	int child_pid;
	int status;
	pid=fork();
	switch (pid){
		case -1:
			perror("fork is failed\n");
			break;
		case 0:
			execl("/bin/ls","ls","-al",NULL);
			perror("execl is failed\n");
			break;
		default:
			child_pid=wait(NULL);
			printf("ls is complete\n");
			printf("Parent PID (%d), Child PID (%d)\n",getpid(),getppid());
			exit(0);

	}
}