Write a program that shows that the getrusage() RUSAGE_CHILDREN flag retrieves information about only the children for which a wait() call has been performed. (Have the program create a child process that consumes some CPU time, and then have the parent call getrusage() before and after calling wait().)

Write a program that executes a command and then displays its resource usage. This is analogous to what the time(1) command does. Thus, we would use this program as follows:

Write programs to determine what happens if a process’s consumption of various resources already exceeds the soft limit specified in a call to setrlimit().

$ ./rusage command arg...