Description
For this assignment, you will use C’s process control functions to exercise basic process creation.
Your program should have the following functionality:
Concurrency
Given up to six commands separated by commas (a comma will be its own token, with whitespace
around it) and any number of arguments each, execute all commands concurrently (i.e., in parallel
and not one after the other).
Each process (excluding the parent) should print their PID followed by their PPID followed by their
command without arguments to stderr. Any normal behavior by the command issued should remain
the same. You do not need to account for redirection or pipelining.
Your program should not produce orphans. Toward verification of this, if a process’s PPID is 1, it
is an orphan that has been adopted by the init process. In solving this problem, be sure that your
child processes still run concurrently. Do not wait for one process to complete before starting a new
one.
Example
$ assign8 ls -a , pwd , cat hello.txt
PID: 35003, PPID: 35002, CMD: ls
PID: 35004, PPID: 35002, CMD: pwd
Assignment 8: Process Control Page 1 of 3
PID: 35005, PPID: 35002, CMD: cat
/home/ssilvestro
. .. courses Desktop Downloads
this is the contents of hello.txt
Note that since the processes are happening in parallel, the order of the output is not guaranteed.
Compiling Your Program
Your submission will include a makefile so the following command can be used to compile your code.
$ make assign8
This should produce an executable file named assign8. For more information about the make utility,
check the related document on Blackboard.
If you attempt the extra credit, $ make assign8-2 should compile the extra credit portion to
assign8-2.
Extra Credit (10 points)
Create a second program, assign8-2 which takes exactly two commands, with any number of
arguments each, and separated by a comma. The program should pipe the output of the first
command to the second using dup2().
Example
$ assign8-2 ls -l , sort -k5 -n
should behave as
$ ls -l | sort -k5 -n
Extra credit is not given to late assignments. All requirements must be met for both parts of the
assignment to qualify for extra credit.
Assignment Data
This assignment does not include sample input files since it will only take arguments.
Program Files
Your submission should consist of up to five files:
• assign8.c – the main file which is compiled (required)
Assignment 8: Process Control Page 2 of 3
• assign8.h – an optional header file if necessary
• assign8-2.c – the main file which is compiled for extra credit (required for extra credit)
• assign8-2.h – an optional header file if necessary
• Makefile – the makefile to make the assign8 executable (required).
Submission
Turn your assignment in via Blackboard. Your zip file, named abc123.zip should contain only the
files described above.
If you attempt the extra credit, name your file abc123_EC.zip. Without the _EC, your submission
will be graded as normal.
Assignment 8: Process Control Page 3 of 3
