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COP 4604-001: Unix System Programming
Spring 2008 Name: ______________________________
Midterm 2 Last 4 digits of ZN: Z x x x x __ __ __ __
This is an OPEN textbook, but CLOSED notes test. You may consult your textbook for syntax
questions. No other reference materials are allowed to be open. NO exchange of information is
allowed among students. Write your answers on the space provided.
1. Zombie processes are wastes of resources. List all possible ways, as covered in class, that a
zombie process can be avoided. (15 pts.)
1. Have parent wait
2. Have it orphaned
3. Have it (SIGCLD) ignored (SV)
4. Call sigaction() with SA_NOCLDWAIT set
2. What are the data types of the C variables in the following C declarations? (20 pts.)
a) int (*fa)(int);
fa is a pointer to an integer function that takes one integer parameter.
b) int (*fb(int, int (*fbb)(void)))(int, int);
fb is a function that takes two arguments (int & function) and returns a pointer to
an integer function with two integer arguments.
fbb is a pointer to an integer function that takes no argument.
c) int *fc(int i, int j);
fc is a function with two integer arguments, and returns an integer.
3. Explain what the following system calls are used for? (20 pts.)
a) signal()
To set up a signal handler
b) kill()
To send a signal
c) alarm()
To setup an alarm clock
d) pause()
To suspend the execution of a process
e) waitpid()
To wait for a specific child (pid) to finish
