waitpid() System Call A parent process usually needs to synchronize its actions by waiting until the child process has either stopped or terminated its actions The waitpid() system call gives a process a way to wait for a process to stop. It's called as follows. pid = waitpid(child, &status, options); In this case, the operating system will block the calling process until the process with ID child ends The options parameter gives ways of modifying the behavior to, for example, not block the calling process. We can just use 0 for options here. When the child process ends, the operating system changes the int variable status to represent how child process ended (incorporating the exit code, should the calling process want that information), and it unblocks the calling process, returning the process ID of the process that just stopped. If the calling process does not have any child associated with it, wait will return immediately with a value of -1 1. Write a program processes.c, and let the parent process produce two child processes. One prints out "I am first child, my pid is: "PID, and the other prints out "I am second child, my pid is: " PID. Guarantee that the parent terminates after the children terminate (Note, you need to wait for two child processes here). Use the getpid() function to retrieve the PID