我正试图从子进程运行twinkle命令行.
例如这样：
int hangup() {
write_on_display("line3"," ");
write_on_display("hide_icon","DIALTONE");
write_on_display("hide_icon","BACKLIGHT");
int pid = fork();
if (pid == 0) {
int res = execl("/usr/bin/twinkle"," ","--immediate","--cmd","answerbye",(char *) NULL);
_exit(0);
} else {
perror("hangup");
return 0;
}
return 1;
}
但闪烁变成僵尸：
10020 pts/1 Z+ 0:00 [twinkle] 我试着设定
信号(SIGCHLD,SIG_IGN);
但没有成功.
实际上我认为儿童过程在闪烁结束之前就已经死了.
从命令行运行闪烁如：
twinkle --immediate --call 100
不会使僵尸 – 闪烁正确关闭.
那里我想念的是什么？
最佳答案
父进程需要使用子进程ID调用
waitpid().从链接的参考页面：
All of these system calls are used to wait for state changes in a child of the calling process,and obtain information about the child whose state has changed. A state change is considered to be: the child terminated; the child was stopped by a signal; or the child was resumed by a signal. In the case of a terminated child,performing a wait allows the system to release the resources associated with the child; if a wait is not performed,then the terminated child remains in a “zombie” state (see NOTES below).
例如：
pid_t pid = fork();
if (0 == pid)
{
/* Child process. */
}
else
{
/* Parent process,wait for child to complete. */
int status;
waitpid(pid,&status,0);
}
