学步园

下面是一个实例，来演示不通的exit值

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

void pt_exit(int status)
{
	if(WIFEXITED(status))
		printf("nomal termination, exit status = %d\n",
				WEXITSTATUS(status));
	else if(WIFSIGNALED(status))
		printf("abnomal termination, signal number = %d%s\n",
				WTERMSIG(status), "");
	else if(WIFSTOPPED(status))
		printf("child stopped, signal number = %d\n",
				WSTOPSIG(status));
}

int main(void)
{
	pid_t pid;
	int status;
	
	if((pid = fork()) < 0)
		printf("error: fork error.\n");
	else if(pid == 0)
		exit(7);

	if(wait(&status) != pid)
		printf("error: wait error.\n");
	pt_exit(status);

	if((pid = fork()) < 0)
		printf("error: fork error.\n");
	else if(pid == 0)
		abort();

	if(wait(&status) != pid)
		printf("error: wait error.\n");
	pt_exit(status);

	if((pid = fork()) < 0)
		printf("error: fork error.\n");
	else if(pid == 0)
		status /= 0;

	if(wait(&status) != pid)
		printf("error: wait error.\n");
	pt_exit(status);
	
	exit(0);
}