Question

Based on this SO post, and this example, I expect that, when I use fork(), will allow me executing system/execvp in non-blocking manner. However, when I try to issue a long-running child process in a fork block in the above mentioned example code, the control does not return to parent block, till the child has finished.

Can you tell a method, how I should design the code to allow non-blocking calls to system, in C/C++ code. Also, I plan to write a program, where more than one chidren are forked from a same parent. How can I get the pid of the children?

Thanks for your kind help.

Answer 1

fork will immediately return to both the child and parent. However, that example (test3.c) calls wait4, which like it sounds, waits for another process to do something (in this case exit).