Operating Systems and Computer Structures G2
Assignment 1
Due date
This assignment is due by 5pm, 17 August at the end of week 5.
Introduction
This assignment requires you to write a shell program that will display a list of commands. When a command is selected from the list it is executed. For example, the list may contain
ls
ls -l
If the command ls is selected, then it will be run showing the
listing of files in the current directory.
Each command should be run asynchronously, so that selecting another command from the list will cause it to run.
The list should be shown using an X Windows application
called xselect which will show the list like this:
Command execution
The program you will create (call itrunit, for example) will run
with either no parameters or one parameter. This parameter will be the name of a
file containing a list of commands. If no file is specified on the command line,
then it will default to the file .runitrc in your home directory.
The list of commands should be stored in the file, one per line.
xselect
The programxselect reads lines of text from standard input. It
shows the input in a list, one line per element of the list. When an item of the
list is selected by clicking on it, the line is sent to standard output.
When the Quit button is pressed, xselect will
exit.
Errors
Ifrunit
is called with more than one argument, an error message should be
printed and execution terminated. If the file used does not exist, an error
should also be reported and execution terminated.
Submission
Do not hand in a copy of the program on paper. Instead, hand it in electronically using the commandgive.
This command runs with two parameters.
The first parameter should be the string ``a1'' and the second should be the
name of the file containing your shell program. For example,
give a1 runit
You may run give any number of times.
Each time you run give it replaces any
earlier submission of the assignment.