Advanced Operating Systems
Enhance the shell from p2 to support the new facilities described below.
Enhance the shell's capabilities with new support for handling signals so
that you can provide some job control. Assume that there will never be
more than 4 processes to manage (foreground, background, suspended).
Also, for simplicity, assume that no task placed into the background will
attempt to read from stdin.
^Z on fg process suspends it
Cause the foreground process to be suspended.
jobs
Builtin command to list current jobs (suspended or background).
List each with a num beside it to be used in following commands.
kill num
Builtin command to cause the specified process to be sent
the -KILL signal.
fg num
Builtin command to cause the specified suspended or background
process to become the foreground process. In this context, the
foreground process is merely the one which the shell is waiting
for to complete.
bg num
Builtin command to cause the specified suspended process to
run in the background. The shell will not wait for the process
to complete because it is in the background. Of course, the
shell may still perform a wait operation as part of handling a
SIGCHLD for the process.
Submitting the project for grading:
The project should compile and link as p3.
You should turnin a tar file containing all of the required files.
To build the project, I will cd to my directory containing your files
and simply type:
rm -rf p3
rm -rf *.o
make
