Project Holberton : C - Simple Shell

Description 📄

Note

Our program is a simple C shell that allows a user to execute commands from the command line. It runs interactively, displaying a prompt (Nico & Tom's Shell$) where the user can enter commands. The program parses these commands, executes them, and displays the results.

Setup 💿

To clone the repo using https://github.com/thomas-maye/holbertonschool-simple_shell.git

Command of Compilation 📥

The compilation command to compile the files that make up the Simple Shell is as follows :

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

Requirements ⚙️

Allowed editors : vi, vim, emacs
Our files compile on Ubuntu 20.04 LTS
Our code of respect Betty code Style and Betty Doc
We have no more than five functions per file
All function prototypes can be found in simple_shell.h

Functions 🧰

main.c :

The program entry point

Prototype : int main(void);

new_shell_prompt.c :

This function displays the prompt and reads user commands

Prototype : void new_shell_prompt(char **env); & Prototype : void handle_cmd_prompt(char **args, char **env);

token.cmd.c :

This function divides the command entered by the user into words called tokens

Prototype : char **token_cmd(char *line); Prototype : int count_tokens(char *line_cmd)

exe_cmd.c :

This function executes the command entered by the user

Prototype : void exe_cmd(char **args, char **env);

find_cmd_in_path.c :

This function searches for the command entered in the path and if the command is executable

Prototype : char *find_cmd_in_path(char *command); & Prototype : char *find_path_in_env(char **env)

print_env.c :

This function displays environment variables

Prototype : void print_env(char **env);

handle_exit.c :

This function manages the program output

Prototype : void handle_exit(void);

free_args.c :

This function frees the memory allocated to the arguments

Prototype : void free_args(char **args);

The header file

Our header file is a file containing C declarations, macro definitions to be shared between several source files, external variables and librairies that we need to execute this program.*

File : simple_shell.h

#ifndef SIMPLE_SHELL_H
#define SIMPLE_SHELL_H

#define DELIMITERS " \t\r\n\a"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>

extern char **environ;

void new_shell_prompt(char **env);
void exe_cmd(char **args, char **env);
char *find_path_in_env(char **env);
char *find_cmd_in_path(char *cmd, char **env);
void print_env(char **env);
char **token_cmd(char *line);
void free_args(char **args);
void handle_cmd_prompt(char **args, char **env);
void handle_man_cmd(char **args);
void handle_builtin_cmd(char **args);
void handle_exit(void);
int count_tokens(char *line_cmd);

#endif

How it Works ▶️

Initialization:
- The main function initializes the shell environment and invokes new_shell_prompt.*
Prompt and Input:
- The shell displays a prompt (Nico & Tom's Shell$) and waits for the user to enter a command.
Command Parsing:
- The entered command is read as a string.
- token_cmd splits the command string into an array of tokens (command and arguments).
Command Execution:
- Built-in commands like exit and env are handled directly within the shell.
- For other commands, exe_cmd is called, which:
  - Searches for the command using find_cmd_in_path.
  - Forks a child process to execute the command with execve.
Error Handling:
- If an invalid command is entered, the shell returns an error message.
- Memory allocated for command arguments and paths is freed after use.
Loop:
- The shell continuously loops back to display the prompt after each command execution, until exit is invoked.

Usage 💡

After compiling, we can run our shellwith :

./hsh

For example, here's what it looks like :

root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# ./hsh
Nico & Tom's Shell$

Examples 🧾

Here are the commands we tested and found to work in interactive mode :

List directory contents:

Nico & Tom's Shell$ ls -l

The result :

total 72
-rwxr-xr-x 1 root root   169 Aug 20 19:38 AUTHORS
-rw-r--r-- 1 root root  3300 Aug 20 10:09 README.md
-rw-r--r-- 1 root root  1386 Aug 20 16:55 exe_cmd.c
-rw-r--r-- 1 root root  1899 Aug 20 10:09 find_cmd_in_path.c
-rw-r--r-- 1 root root   561 Aug 20 21:27 free_args.c
-rw-r--r-- 1 root root   368 Aug 16 12:36 handle_exit.c
-rw-r--r-- 1 root root  1611 Aug 20 19:38 handle_man_cmd.c
-rwxr-xr-x 1 root root 17848 Aug 20 21:27 hsh
-rw-r--r-- 1 root root   763 Aug 16 12:36 main.c
-rwxr-xr-x 1 root root  2512 Aug 20 19:38 man_1_simple_shell
-rw-r--r-- 1 root root  1726 Aug 20 19:38 new_shell_prompt.c
-rw-r--r-- 1 root root   450 Aug 16 12:36 print_env.c
-rw-r--r-- 1 root root   967 Aug 20 19:38 simple_shell.h
-rw-r--r-- 1 root root  1703 Aug 20 11:06 token_cmd.c
Nico & Tom's Shell$

List of files in the current directory

Nico & Tom's Shell$ ls

The result :

AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h	token_cmd.c
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c

Print Working directory

Nico & Tom's Shell$ pwd

The result :

/workspace/Holberton/holbertonschool-simple_shell

List of files in the current directory with a path

Nico & Tom's Shell$ /bin/ls

The result :

AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h	token_cmd.c
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c

Print environment variables:

Nico & Tom's Shell$ env

The result :

HOSTNAME=e6dde706a7d3
PWD=/workspace/Holberton/holbertonschool-simple_shell
HOME=/root
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=00:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.avif=01;35:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.webp=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:*~=00;90:*#=00;90:*.bak=00;90:*.crdownload=00;90:*.dpkg-dist=00;90:*.dpkg-new=00;90:*.dpkg-old=00;90:*.dpkg-tmp=00;90:*.old=00;90:*.orig=00;90:*.part=00;90:*.rej=00;90:*.rpmnew=00;90:*.rpmorig=00;90:*.rpmsave=00;90:*.swp=00;90:*.tmp=00;90:*.ucf-dist=00;90:*.ucf-new=00;90:*.ucf-old=00;90:
LESSCLOSE=/usr/bin/lesspipe %s %s
TERM=xterm
LESSOPEN=| /usr/bin/lesspipe %s
SHLVL=1
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
OLDPWD=/
_=./hsh
Nico & Tom's Shell$

Exit the shell:

Nico & Tom's Shell$ exit

The result :

root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell#

Here are the commands we tested and found to work in non interactive mode :

root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# echo "qwerty" | /bin/sh
/bin/sh: 1: qwerty: not found
root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# echo "qwerty" | /bin/../bin/sh
/bin/../bin/sh: 1: qwerty: not found
root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell#

root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# echo "/bin/ls" | ./hsh
AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c		token_cmd.c

root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# cat test_ls_2 | ./hsh
AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h	token_cmd.c
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c		test_ls_2
AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h	token_cmd.c
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c		test_ls_2
root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# echo "/bin/ls" | ./hsh
AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h	token_cmd.c
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c		test_ls_2
root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# cat test_ls_2 
/bin/ls
/bin/ls
root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell# cat test_ls_2 | ./hsh
AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h	token_cmd.c
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c		test_ls_2
AUTHORS    exe_cmd.c	       free_args.c    handle_man_cmd.c	main.c		    new_shell_prompt.c	simple_shell.h	token_cmd.c
README.md  find_cmd_in_path.c  handle_exit.c  hsh		man_1_simple_shell  print_env.c		test_ls_2
root@e6dde706a7d3:/workspace/Holberton/holbertonschool-simple_shell#

Man page 📑

The man page is written in the man_1_simple_shell file with a special layout. To display it, simply write man hsh in our new terminal or falling that use man ./man_1_simple_shell.

Memory leaks

In order to identify memory leaks in our program, we used the valgrind tool as follows:

Nico & Tom's Shell$ valgrind --leak-check=full ./hsh

Authors 👨🏻‍💻👨🏻‍💻

Note

C#24 : Nicolas MARTINEZ & Thomas MAYE

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Project Holberton : C - Simple Shell

Description 📄

Setup 💿

Command of Compilation 📥

Requirements ⚙️

Functions 🧰

The header file

How it Works ▶️

Usage 💡

Examples 🧾

Here are the commands we tested and found to work in interactive mode :

Here are the commands we tested and found to work in non interactive mode :

Man page 📑

Memory leaks

Authors 👨🏻‍💻👨🏻‍💻

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Name		Name	Last commit message	Last commit date
Latest commit History 47 Commits
.gitignore		.gitignore
AUTHORS		AUTHORS
README.md		README.md
exe_cmd.c		exe_cmd.c
find_cmd_in_path.c		find_cmd_in_path.c
free_args.c		free_args.c
handle_exit.c		handle_exit.c
handle_man_cmd.c		handle_man_cmd.c
hsh		hsh
main.c		main.c
man_1_simple_shell		man_1_simple_shell
new_shell_prompt.c		new_shell_prompt.c
print_env.c		print_env.c
simple_shell.h		simple_shell.h
token_cmd.c		token_cmd.c

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Project Holberton : C - Simple Shell

Description 📄

Setup 💿

Command of Compilation 📥

Requirements ⚙️

Functions 🧰

The header file

How it Works ▶️

Usage 💡

Examples 🧾

Here are the commands we tested and found to work in interactive mode :

Here are the commands we tested and found to work in non interactive mode :

Man page 📑

Memory leaks

Authors 👨🏻‍💻👨🏻‍💻

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