(in C programming language and Unix ) please help

8-Write a program to create one child process. Then the parent reads from the user an integer number N and compute the factorial N! then write it on another shared anonymous m terminates. The parent prints both X and Y. Finally, unmap the memory. Check for all possible saves it in a shared anonymous memory mapped area X. The child process emory mapped area Y and system errors with proper error messages. Save the file as "lab10c.c a. Include the source file in your lab report. b. Compile and link the program as labl0c. Show the commands used in the lab report c. Run the program and include the output to the report