How to make parent wait for all child processes to finish?

by 
pid_t child_pid, wpid;
int status = 0;

//Father code (before child processes start)

for (int id=0; id<n; id++) {
    if ((child_pid = fork()) == 0) {
        //child code
        exit(0);
    }
}

while ((wpid = wait(&status)) > 0); // this way, the father waits for all the child processes 

//Father code (After all child processes end)

wait waits for a child process to terminate, and returns that child process’s pid. On error (eg when there are no child processes), -1 is returned. So, basically, the code keeps waiting for child processes to finish, until the waiting errors out, and then you know they are all finished.

More Related Contents:

  1. Why do I get two values for this variable when forking?
  2. How to make child process die after parent exits?
  3. how to exit a child process – _exit() vs. exit
  4. What is the difference between fork and thread?
  5. Just check status process in c
  6. How do I make this Linux program compile? [closed]
  7. What is the difference between sigaction and signal?
  8. Redirecting exec output to a buffer or file
  9. What does fflush(stdin) do in C programing? [duplicate]
  10. What does “#define _GNU_SOURCE” imply?
  11. What happens in OS when we dereference a NULL pointer in C?
  12. popen() alternative
  13. How does fork() work?
  14. Can popen() make bidirectional pipes like pipe() + fork()?
  15. Is there a way to flush a POSIX socket?
  16. Can the order of execution of fork() be determined?
  17. What is the difference between using _exit() & exit() in a conventional Linux fork-exec?
  18. Waiting for all child processes before parent resumes execution UNIX
  19. Why is rand() not so random after fork?
  20. Recursive mkdir() system call on Unix
  21. Linux/POSIX equivalent for Win32’s CreateEvent, SetEvent, WaitForSingleObject
  22. How do I find the current machine’s full hostname in C (hostname and domain information)?
  23. Why does my compiler not accept fork(), despite my inclusion of ?
  24. Why does wait() set status to 255 instead of the -1 exit status of the forked process?
  25. Why does this code print two times? [duplicate]
  26. Pipe two or more shell commands in C using a loop
  27. C – Retrieving a child’s exit status that is larger than 8 bits
  28. Visually what happens to fork() in a For Loop
  29. Checking if errno != EINTR: what does it mean?
  30. How to know if a Linux system call is restartable or not?

Leave a Comment