问题
I'm trying to figure out what the pid is of a process that sent the SIGCHLD signal, and I want to do this in a signal handler I created for SIGCHLD. How would I do this? I'm trying:
int pid = waitpid(-1, NULL, WNOHANG);
because I want to wait for any child process that is spawned.
回答1:
If you use waitpid()
more or less as shown, you will be told the PID of one of the child processes that has died — usually that will be the only process that has died, but if you get a flurry of them, you might get one signal and many corpses to collect. So, use:
void sigchld_handler(int signum)
{
pid_t pid;
int status;
while ((pid = waitpid(-1, &status, WNOHANG)) != -1)
{
unregister_child(pid, status); // Or whatever you need to do with the PID
}
}
You can replace &status
with NULL
if you don't care about the exit status of the child.
来源:https://stackoverflow.com/questions/2595503/determine-pid-of-terminated-process