holbertonschool-simple_shell

Table of Contents

• holbertonschool-simple_shell
  • Table of Contents
  • Description
  • Requirements
  • Compilation
  • Return
  • Examples
  • Documentation
  • Memory Leaks
  • Flowchart
  • Bugs
  • Authors

Description

This project is a simple shell implementation for Holberton School. It serves as a UNIX command interpreter, replicating some functionalities of the simple shell sh. It allows users to execute commands, navigate directories, and handle input/output redirection. The shell supports both interactive and non-interactive modes, providing a convenient and efficient way to interact with the underlying operating system.

Requirements

• All your files will be compiled on Ubuntu 20.04 LTS using gcc, using the options -Wall -Werror -Wextra -pedantic -std=gnu89
• Your code should use the Betty style. It will be checked using betty-style.pl and betty-doc.pl
• Global variables are not allowed
• No more than 5 functions per file

The following functions and system calls are allowed:

• all functions from string.h
• access (man 2 access)
• chdir (man 2 chdir)
• close (man 2 close)
• closedir (man 3 closedir)
• execve (man 2 execve)
• exit (man 3 exit)
• _exit (man 2 _exit)
• fflush (man 3 fflush)
• fork (man 2 fork)
• free (man 3 free)
• getcwd (man 3 getcwd)
• getline (man 3 getline)
• getpid (man 2 getpid)
• isatty (man 3 isatty)
• kill (man 2 kill)
• malloc (man 3 malloc)
• open (man 2 open)
• opendir (man 3 opendir)
• perror (man 3 perror)
• printf (man 3 printf)
• fprintf (man 3 fprintf)
• vfprintf (man 3 vfprintf)
• sprintf (man 3 sprintf)
• putchar (man 3 putchar)
• read (man 2 read)
• readdir (man 3 readdir)
• signal (man 2 signal)
• stat (__xstat) (man 2 stat)
• lstat (__lxstat) (man 2 lstat)
• fstat (__fxstat) (man 2 fstat)
• strtok (man 3 strtok)
• wait (man 2 wait)
• waitpid (man 2 waitpid)
• wait3 (man 2 wait3)
• wait4 (man 2 wait4)
• write (man 2 write)

Compilation

Your shell will be compiled this way:

gcc -Wall -Werror -Wextra -pedantic *.c -o simple_shell

Return

• The return value of the function is the status of the command executed
• In case of failure, the return value is -1
• In case of success, the return value is 0
• In case of exit, the return value is 2
• In case of Ctrl+D, the return value is 1
• In case of a command not found, the return value is 127
• In case of a permission denied, the return value is 126

Examples

• Interactive mode:

$ ./simple_shell
($) /bin/ls
Desktop   Documents    Downloads    Music    Pictures    Public    Templates    Videos simple_shell
($)
($) exit
$

• Non-interactive mode:

$ echo "/bin/ls" | ./simple_shell
Desktop   Documents    Downloads    Music    Pictures    Public    Templates    Videos simple_shell
$ cat test_ls_2
/bin/ls
/bin/ls
$ cat test_ls_2 | ./simple_shell
Desktop   Documents    Downloads    Music    Pictures    Public    Templates    Videos simple_shell
Desktop   Documents    Downloads    Music    Pictures    Public    Templates    Videos simple_shell

Documentation

To access the documentation for simple_shell, run the following command:

man ./man_1_simple_shell

Memory Leaks

To check for memory leaks in simple_shell, run the following command:

valgrind --leak-check=full --show-leak-kinds=all ./simple_shell

Flowchart

The following flowchart illustrates the process of the simple shell:

										
		 ┌────────────────────┐         
 ┌───────>       Start!       │         
 │       │                    │         
 │       └────────────────────┘         
 │                 │                    
 │          ┌──────∨───────┐            
 │    ┌─────┼    Main      ┼────┐       
 │    │     └──────────────┘    │       
 │ ┌──∨───────────┐   ┌─────────∨───┐   
 │ │              │   │             │   
 │ │ Non          │   │ Interactive │   
 │ │ Interactive  │   │             │   
 │ │              │   │             │   
 │ └──────────────┘   └─────────────┘   
 │  │      ┌────────────────┐    │      
 │  │      │  Interpreter   <────┘      
 │  │      └───────┼────────┘           
 │  └──────>───────∨────────┐           
 └─────────└─── Execute  ───┘           

Bugs

• No known bugs at this time.

Authors

• Melvin Redondo--Tanis