waitpid and grandchildren Post: 302642877

Sponsored Content

Top Forums Programming waitpid and grandchildren Post 302642877 by otheus on Friday 18th of May 2012 06:35:48 AM

05-18-2012

Registered User

Quote:

Once I get the final PID of the daemon in question, I detach from it with a PTRACE_DETACH and let it run unhindered.

My understanding is that once you detach a process, you no longer get signals like SIGCHLD on its behalf.

But the idea of using ptrace for this kind of thing seems novel to me.

Quote:

can I monitor a given grandchild process without becoming the init process

. DJ Bernstein's Daemontools offers a solution. You leave a file-descriptor open to the grandparent (so your monitoring program never truly detaches).

otheus

View Public Profile for otheus

Find all posts by otheus

3 More Discussions You Might Find Interesting

1. Programming

problems with FORK() and WAITPID()

Dear All, I'm trying to write multithreading TCP Daemon which executes external program when new network connection arrives on a socket. After accept() I'm doing fork() for initiating of new child process, in which will be executed external program. After child creation I'm doing fork() again,...

2. Programming

waiting for multiple childs - C - waitpid

Hi gurus, I would like to fork more children and then write their return values: so far I tried: #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <unistd.h> #include <sys/types.h> #include <sys/wait.h> int main(void) { pid_t pid; int rv=0, i; ...

3. Programming

[C]Fork and waitpid

Hi folks, I am writing a simple program to understand how fork() and waitpid works, but it doesn't seem that is working like I wanted. if(fork()==0){ //el hijo pid1=getpid(); printf("\nSoy el hijo %d",pid1); }else { //el padre if (fork()==0) { //el hijo pid2=getpid();...

LEARN ABOUT DEBIAN

tty

TTY(4)							     Linux Programmer's Manual							    TTY(4)

NAME

       tty - controlling terminal

DESCRIPTION

       The  file /dev/tty is a character file with major number 5 and minor number 0, usually of mode 0666 and owner.group root.tty.  It is a syn-
       onym for the controlling terminal of a process, if any.

       In addition to the ioctl(2) requests supported by the device that tty refers to, the ioctl(2) request TIOCNOTTY is supported.

   TIOCNOTTY
       Detach the calling process from its controlling terminal.

       If the process is the session leader, then SIGHUP and SIGCONT signals are sent to the foreground process group and  all	processes  in  the
       current session lose their controlling tty.

       This ioctl(2) call only works on file descriptors connected to /dev/tty.  It is used by daemon processes when they are invoked by a user at
       a terminal.  The process attempts to open /dev/tty.  If the open succeeds, it detaches itself from the terminal by using  TIOCNOTTY,  while
       if the open fails, it is obviously not attached to a terminal and does not need to detach itself.

FILES

       /dev/tty

SEE ALSO

       chown(1), mknod(1), ioctl(2), termios(3), console(4), tty_ioctl(4), ttyS(4), agetty(8), mingetty(8)

COLOPHON

       This  page is part of release 3.44 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2003-04-07								    TTY(4)