A shell is a computer program that exposes an operating system's services to a human user or other programs. In general, operating system shells use either a command-line interface (CLI) or graphical user interface (GUI), depending on a computer's role and particular operation. It is named a shell because it is the outermost layer around the operating system. Command-line shells require the user to be familiar with commands and their calling syntax, and to understand concepts about the shell-specific scripting language (for example, bash). Graphical shells place a low burden on beginning computer users, and are characterized as being easy to use. Read more here
I did the project to improve my understanding of the C language and how to the shell works in general. During the process I learnt a lot of things some of which I have listed below.
Who designed and implemented the original Unix operating system
Who wrote the first version of the UNIX shell
Who invented the B programming language (the direct predecessor to the C programming language)
Who is Ken Thompson
How does a shell work
What is a pid and a ppid
How to manipulate the environment of the current process
What is the difference between a function and a system call
How to create processes
What are the three prototypes of main
How does the shell use the PATH to find the programs
How to execute another program with the execve system call
How to suspend the execution of a process until one of its children terminates
What is EOF / “end-of-file”?
Run the line below in your command line.
NB: Make sure you are in the same folder where the simple shell project files are located.
gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o simpleshell
After the statement finishes running, start using your shell
./simpleshell
After that line, you will be in simple shell
example command ls - It will list all the file in the current directory.
Please report all bugs encountered using this issues link.
THANK YOU