🐚 Simple Shell

To close our Low Level Programming module, we are expected to create a simple UNIX command Interpreter using C.

👀 Shell Overview

Our simple Shell is a UNIX command Line interpreter that reads commands from the standard input or a file and executes them.

🚀 How our simple shell works :

It consists of a an infinite loop that is only interrupted by reaching End of File (EOF) or pressing exit . it follows the following steps :

Reads the command(s) from the standard Input.
Parses the command(s)
Executes the command (s) which takes few other important steps:
- search the command in the environment
- search for the path
- create the child process to execute the command
- Free the allocated memory && the command output
- Go back to the begining of the infinite loop and print a prompt .

📈 Flowchart

To better understand the Logic behind our simple shell, please check this Flowchart :

🔎 Compilation

Our shell is compiled this way:

-gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hsh

🔎 Testing

We are Testing the shell in non interactive mode via these cases :

-$ ./hsh
($) /bin/ls
hsh main.c shell.c
($)
($) exit
$

And in Interactive mode via these cases:

-$ echo "/bin/ls" | ./hsh
hsh main.c shell.c test_ls_2
$
$ cat test_ls_2
/bin/ls
/bin/ls
$
$ cat test_ls_2 | ./hsh
hsh main.c shell.c test_ls_2
hsh main.c shell.c test_ls_2
$

✒️ Examples :

ls
AUTHORS  README.md  execute_the_line.c  get_the_line.c 
hsh  main.h  mainshell.c    man_1_simple_shell.1 
parse_the_line.c  shell.c



pwd
/home/amine/pf/holbertonschool-simple_shell


ls -l
total 40
-rw-r--r-- 1 root root  142 Dec  9 08:25 AUTHORS
-rw-r--r-- 1 root root 2773 Dec  9 12:48 README.md
-rw-r--r-- 1 root root 1179 Dec  9 04:38 Read.txt
-rw-r--r-- 1 root root  455 Dec  9 12:46 execute_the_line.c
-rw-r--r-- 1 root root  483 Dec  9 12:46 get_the_line.c
-rw-r--r-- 1 root root  275 Dec  9 12:46 main.h
-rw-r--r-- 1 root root  374 Dec  9 09:01 mainshell.c
-rw-r--r-- 1 root root 3563 Dec  9 12:46 man_1_simple_shell.1
-rw-r--r-- 1 root root  381 Dec  9 12:46 parse_the_line.c
-rw-r--r-- 1 root root  492 Dec  9 12:46 shell.c

📑 Files Architecture

-  main.h : Header file containing all functions prototypes and included header files 
-  mainshell.c : contains the function calls contributing the shell work 
-  get_the_line.c : gets the user input from the standard input
-  parse_the_line.c : takes the line of command and divides it.
- env.c : gets and prints the environment
-  shell.c : contains the checks before executing the main program
- AUTHORS : file containing authors' names and their github usernames

📱 Functions and System Calls Used

- execve 
- exit 
- fork 
- free 
- getpid 
- malloc 
- perror 
- printf 
- strtok

Aminekham/holbertonschool-simple_shell