Simple Shell

holbertonschool-simple_shell

Description

As the first trimester final project our purpose on that, is to create simple UNIX command-line interpreter (shell) that displays a prompt and executes simple commands entered by the user. This project demonstrates the basic functionality of a shell, such as reading user input, forking processes, and executing commands using execve.

Compilation

To run the shell:

First compile and execute your program using the following steps of commands:

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

 ./hsh

How will it work ?

After the execution of your program shell displays a prompt Xshell> (in our case, but can be changed based on your prompt), awaiting user input. The user can enter simple commands, and the shell will attempt to execute them. If the command cannot be executed, an error message is displayed, and the prompt is shown again.

Steps of the program

Display Prompt: Prints the prompt Xshell> to indicate that the shell is ready to receive a command.
Read Input: Uses getline() to read the command line entered by the user.
Handle EOF: If Ctrl+D (EOF) is entered, the shell exits.
Fork Process: Creates a new process using fork().
Execute Command: In the child process, uses execve() to execute the command. If execution fails, prints an error message and exits.
Wait for Completion: In the parent process, waits for the child to complete.
Loop: Repeats the process, displaying the prompt again.

Testing

In interactive mode:

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

In non-interactive mode:

$ 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
$

Error Handling

If execve() cannot find or execute the specified command, the shell displays an error message, including a brief explanation of the error (using perror()), and then returns to the prompt.
If the fork() call fails, the shell exits with an error message.
Unless specified otherwise, your program must have the exact same output as sh (/bin/sh) as well as the exact same error output.
The only difference is when you print an error, the name of the program must be equivalent to your argv[0] (See below)

Example of error with sh:

$ echo "qwerty" | /bin/sh
/bin/sh: 1: qwerty: not found
$ echo "qwerty" | /bin/../bin/sh
/bin/../bin/sh: 1: qwerty: not found
$

Same error with your program hsh:

$ echo "qwerty" | ./hsh
./hsh: 1: qwerty: not found
$ echo "qwerty" | ./././hsh
./././hsh: 1: qwerty: not found
$

How to Exit ?

To exit the shell, you can either:

Press Ctrl+D to trigger the "end-of-file" condition.
Type exit and press Enter (this will likely result in an error message since exit isn't implemented as a built-in command, but it indicates the intention to exit).

shukufabayramzada / holbertonschool-simple_shell