SIMPLE SHELL

This repository contains the 'simple' shell project. A project mimicking the Unix shell first invented by Ken Thompson. Collaborative effort

By

• Akinade Hassan Babatunde github

1. Simple shell 0.1

Write a UNIX command line interpreter.

• Usage: simple_shell

Your Shell should:

• Display a prompt and wait for the user to type a command. A command line always ends with a new line.
• The prompt is displayed again each time a command has been executed.
• The command lines are simple, no semicolons, no pipes, no redirections or any other advanced features.
• The command lines are made only of one word. No arguments will be passed to programs.
• If an executable cannot be found, print an error message and display the prompt again.
• Handle errors.
• You have to handle the “end of file” condition (Ctrl+D)

You don’t have to:

• use the PATH
• implement built-ins
• handle special characters : ", ', `, , *, &, #
• be able to move the cursor
• handle commands with arguments

2. Simple shell 0.2

Simple shell 0.1 +

• Handle command lines with arguments

3. Simple shell 0.3

Simple shell 0.2 +

• Handle the PATH
• fork must not be called if the command doesn’t exist

4. Simple shell 0.4

Simple shell 0.3 +

• Implement the exit built-in, that exits the shell
• Usage: exit
• You don’t have to handle any argument to the built-in exit

5. Simple shell 1.0

Simple shell 0.4 +

• Implement the env built-in, that prints the current environment

6. Simple shell 0.1.1

Simple shell 0.1 +

• Write your own getline function
• Use a buffer to read many chars at once and call the least possible the read system call
• You will need to use static variables
• You are not allowed to use getline

You don’t have to:

• be able to move the cursor

7. Simple shell 0.2.1

Simple shell 0.2 +

• You are not allowed to use strtok

8. Simple shell 0.4.1

Simple shell 0.4 +

• handle arguments for the built-in exit
• Usage: exit status, where status is an integer used to exit the shell

9. setenv, unsetenv