Simple Shell

In this project, we coded from scratch a simple Unix shell. A shell is an interactive command-line interpreter. We created a shell that would utilize the command line interface (CLI). It allows users to type in a defined set of commands (e.g. "rm" to remove files, "cat" to combine word documents, etc) and have the operating system run the appropriate function. It is slightly different from a graphical user interface (GUI). For instance, instead of using a mouse to click to open folders and delete files, a user can type in a command (i.e. "ls" or "rm") and have the files be displayed or modified in a list on the command line. GUI and CLI both have the same purpose to interact with the operating system but their input methods are different and some developers prefer the CLI to interact with the shell because their typing is quicker than clicking and dragging.

Synopsis

This repository holds all the code necessary for our custom simple shell to run. Our shell currently handles the executions of executables found in the environmental variable PATH, with or without their full paths. Sample commands that our shell supports include ls (/bin/ls), pwd, echo, which, whereis.

Builtins

• exit exits shell (Usage: exit [status])
• env prints environmental variables (Usage: env)

Functions and system calls used

read, signal, malloc, free, getcwd, chdir, access, execve, wait, write, exit

Description of what each file shows:

man_3_shell ------------------------ custom manpage for our simple shell
main.c ----------------------------- holds entrance into program
shell.h ---------------------------- holds prototypes of functions spread across all files
execute_command.c ------------------ Executes a builtin command
parse_input.c ---------------------- Parses the user input to get the command and arguments
prompt.c --------------------------- holds the prompt ($)

Environment

• Language: C
• OS Ubuntu: 20.4
• Compiler: gcc 9.4.0
• Style guidelines: Betty style

How To Install, Compile, and Use

Install and Compile

(your_terminal)$ git clone https://github.com/Touka01/holbertonschool-simple_shell.git
(your_terminal)$ cd simple_shell
(your_terminal)$ gcc -Wall -Werror -Wextra -pedantic -Wno-format *.c -o simple_shell

Non-Interactive Mode

echo "ls -l" | ./simple_shell

Interactive Mode* Activate the shell

(your_terminal)$ ./simple_shell
$

Sample Usage

$ ls -al
total 4
-rw-rw-r-- 1 vagrant vagrant   234 Mar 28 19:32 file1.c
-rw-rw-r-- 1 vagrant vagrant    69 Mar 28 19:32 file2.c
$ echo "This is a pretty cool!"
This is pretty cool!
$ man ./man_1_simple_shell (opens our manpage for more information)

Stop and return to your original shell

$ exit
(your_terminal)$

To Do

• More functionality can still be added (e.g. handle aliases, pipelines, and redirections)

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Authors

Ahmed Toukebri Raed Bedouich