OUR OWN BASIC SHELL

This project is about how build our own simple shell program

Steps if you want try this program

1. git clone https://github.com/LuisPatino92/simple_shell.git
2. cd simple_shell
3. For compile the shell gcc -Wall -Werror -Wextra -pedantic *.c -o hsh
4. Execute ./hsh

FILES

t all individuals having contributef content to the repository

#	Directory	Description
1	README.md	...
2	entry_point.c	Begining entry point to simple shell (main)
3	interactive.c	Functions that interpret the interactive mode and display the new prompt
4	non_interactive_mode	Functions that interpret the non interactive mode and display the new prompt
5	leak_control.c	Special functions for not having many memory leaks
6	interpreter.c	contain funtions to help iterpreter the input command in a simple shell
7	_getline.c	Reads the command from STDIN and tokenizes it
8	execute.c	executes a process
9	aux_strings.c	auxiliar functions for simple_shell
10	aux_strings1.c	auxiliar functions for simple_shell
11	shell.h	Header file with prototypes of the functions
12	man_1_simple_shell	Manual of simple shell
13	AUTHORS	File that lis

Description of the programm

The program simple_shell that takes command from the input

The prompt looks like this:

[#FAKE SHELL] /.../simple_shell $

This simple shell can works in:

• Display a prompt and wait for the user to type a command. A command line always ends with a new line.
• Handle command lines with arguments
• Handle the PATH
• The prompt is displayed again each time a command has been executed.
• The command lines are simple, no semicolons, no pipes, no redirections or any other advanced features.
• The command lines are made only of one word. - If an executable cannot be found, print an error message and display the prompt again.
• Handle errors.
• have to handle the “end of file” condition (Ctrl+D)
• Implement the exit built-in, that exits the shell
• Implement the env built-in, that prints the current environment
• Have own function _getline
• Handle Ctrl+C
• Not have memory leaks

FUNCTIONS IN SIMPLE SHELL

| Prototype |	| Description |
int main(void)	Entry point to simple command line interpeter
char **_getline(void)	_getline - Reads the command from STDIN and tokenizes it
void interactive_mode(void)	Interactive commandline interpeter
void show_prompt(void)	Shows a prompt on the stdout
void non_interactive_mode(void)	executes one comman passed as pipeline to STDIN
void execute(char *command, char **args)	executes a process
void interpeter(char **command, int loop)	Interprets a command
char *get_valid_exe(char *command)	finds for a valid command to execute
int include_path(char *command)	Checks if command is a path
char **path_tokenizer(void)	Tokenizes the path
char *connect(char *msj1, char *msj2)	Conect two strings
int _strlen(char *str)	Measure the length of a strings
int _strncmp(const char *s1, const char *s2, int n)	Compare n bytes of two strings
char **_strtok(char *str, char delimiter)	Is a double pointer that Splits a string in separated words
char *write_word(char *str, char delimiter)	Write a word on the desired direction
int length_d(char *str, char delimiter)	Computes the length of a strings until a delimiter

List of system calls

• execve (man 2 execve)
• exit (man 3 exit)
• fork (man 2 fork)
• free (man 3 free)
• isatty (man 3 isatty)
• malloc (man 3 malloc)
• read (man 2 read)
• signal (man 2 signal)
• stat (__xstat) (man 2 stat)
• wait (man 2 wait)
• write (man 2 write)

FLOWCHAR

Examples

-->

$ ls

AUTHORS     aux_strings.c   execute.c      leak_control.c      testing
README.md   aux_strings1.c  hsh            man_1_simple_shell
_getline.c  built_ins.c     interactive.c  non_interactive.c
a.out       entry_point.c   interpeter.c   shell.h

$ ls -l

total 84
-rw-r--r-- 1 luna luna   190 Nov 25 18:55 AUTHORS -rw-r--r-- 1 luna luna  4468 Nov 25 23:20 README.md
-rw-r--r-- 1 luna luna   890 Nov 25 23:23 _getline.c
-rwxr-xr-x 1 luna luna 18496 Nov 25 17:58 a.out
-rw-r--r-- 1 luna luna  2583 Nov 25 19:09 aux_strings.c
-rw-r--r-- 1 luna luna  1839 Nov 25 19:36 aux_strings1.c
-rw-r--r-- 1 luna luna   564 Nov 26 11:27 built_ins.c
-rw-r--r-- 1 luna luna   230 Nov 25 15:12 entry_point.c
-rw-r--r-- 1 luna luna   339 Nov 25 19:42 execute.c
-rwxr-xr-x 1 luna luna 18496 Nov 25 19:10 hsh
-rw-r--r-- 1 luna luna  1406 Nov 25 16:56 interactive.c
-rw-r--r-- 1 luna luna  2674 Nov 25 10:55 interpeter.c
-rw-r--r-- 1 luna luna  1910 Nov 25 19:46 leak_control.c
-rw-r--r-- 1 luna luna   582 Nov 25 16:57 man_1_simple_shell
-rw-r--r-- 1 luna luna   382 Nov 26 11:27 non_interactive.c
-rw-r--r-- 1 luna luna  1327 Nov 25 19:09 shell.h
drwxr-xr-x 1 luna luna  4096 Nov 25 10:55 testing

$ /bin/ls

AUTHORS    _getline.c  aux_strings.c   built_ins.c    execute.c  interactive.c  leak_control.c      non_interactive.c  testing
README.md  a.out       aux_strings1.c  entry_point.c  hsh        interpeter.c   man_1_simple_shell  shell.h

$ /bin/ls /bin/ls /bin/ls

/bin/ls /bin/ls

$ echo simple example

simple example

$ inexistent_command

./hsh: 1:  inexistent_command: not found

MADE BY

• LUIS ALEJANDRO PATIÑO ARBOLEDA
• GIRALUNA GOMEZ LONDOÑO