apue实例15.15怎么停止进程啊，看代码不应该直接回车就行么，为什么还是跳不出for循环

Question

源代码:
#include "apue.h"
#include

int
main(void)
{
char line[MAXLINE];
FILE *fpin;

if ((fpin = popen("myuclc", "r")) == NULL)
    err_sys("popen error");
for ( ; ; ) {
    fputs("prompt> ", stdout);
    fflush(stdout);
    if (fgets(line, MAXLINE, fpin) == NULL)
        break;
    if (fputs(line, stdout) == EOF)
        err_sys("fputs error to pipe");
}
if (pclose(fpin) == -1)
    err_sys("pclose error");
putchar('\n');
exit(0);

}
直接输入回车还是会显示prompt> 等待输入啊

Answer 1

http://blog.csdn.net/gaoxuelin/article/details/9852785