What\'s the best way for a running C or C++ program that\'s been launched from the command line to put itself into the background, equivalent to if the user had launched fro
If you need a script to have the PID of the program, you can still get it after a fork.
When you fork, save the PID of the child in the parent process. When you exit the parent process, either output the PID to STD{OUT,ERR} or simply have a return pid; statement at the end of main(). A calling script can then get the pid of the program, although it requires a certain knowledge of how the program works.