Killing a process leaves zombie process to haunt me… :(

Question

I have a program wherein i use fork. In the child process, i just login to a remote server and executes a command. In the parent process, i wait for the child to finish its task. If it doesnot finish it in a predetermined amount of time, i kill the child process using kill(child_pid, SIGTERM). But i have noticed that this leaves behind zombie process like

93113 s000  Z+ 0:00.00 (ssh)

and as the timeouts increase, the zombie process also increase and ultimately the ssh cannot be used anymore.

how can i kill the child process without creating zombies that haunt me??

Answer 1

Even if you kill the child, you still need to wait for it.

Answer 2

You must listen for SIGCHLD in the parent process and get the exit code of the child using wait() et al.