Path: utzoo!attcan!uunet!virtech!cpcahil
From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.unix.questions
Subject: Re: what the kill() system call should do??
Message-ID: <1990Sep27.111849.3088@virtech.uucp>
Date: 27 Sep 90 11:18:49 GMT
References: <25784.2700d355@kuhub.cc.ukans.edu>
Reply-To: cpcahil@virtech.UUCP (Conor P. Cahill)
Organization: Virtual Technologies Inc., Sterling VA
Lines: 26

In article <25784.2700d355@kuhub.cc.ukans.edu> jian@kuhub.cc.ukans.edu writes:
>
>I tried to send a signal (SIGUSR1) from a child process to its parent process
>by using kill() system call in C. The result was funny. Whenever the parent
>process received the signal, it died immediately. I don't know what goes wrong
>in my program. Any help appreciated.
>
>void parent_process()
>{
>  int ppid;
>  switch( pid = fork()) {
>    case -1:      perror("for()");      exit(1);
>    case 0:       ppid = getpid();      child_process(ppid);
>     default:     signal(SIGUSR1, catch_usr1);
>  }

I assume the getpid() is a typo and you really had getppid() in the code.

Most likely the child process is executing the kill() before the parent
process has a chance to execute the signal().    Try running the signal before
the fork (and if necessary, reset it in the child).

-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
                                                Sterling, VA 22170