This project is a simple UNIX command-line interpreter, also known as a shell. It is capable of reading commands from standard input, parsing them, and executing them.
- 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)
- isatty (man 3 isatty)
- kill (man 2 kill)
- malloc (man 3 malloc)
- open (man 2 open)
- opendir (man 3 opendir)
- perror (man 3 perror)
- 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)
The project is organized as follows:
.
├── AUTHORS
├── README.md
├── LICENSE
├── CODE_OF_CONDUCT.md
├── simple_shell.1 (man page)
├── shell.h
├── main.c
├── get_input.c
├── get_line.c*
├── prompt.c
├── tokenizer.c
├── execute.c
├── free.c
├── signal_handler.c
├── built-ins Funcs:
│ ├── get_env.c
│ ├── bultins_shell_cd.c
│ ├── bultins_shell_exit.c
│ ├── bultins_shell_help.c
│ ├── bultins_set_env.c
│ └──── bultins_unset_env
├── Path Funcs:
│ ├── get_path.c
│ ├── find_in_path.c
│ ├── set_path.c
│ ├── append_to_path.c
│ └── prepend_to_path.c
├── error.c
└── utils:
├── utils_func1.c
├── utils_func2.c
└── utils_func2.c
AUTHORS file lists the contributors to the project.
README.md file you are currently reading is a brief overview of the project.
man_1_simple_shell file is the man page for the shell.
shell.h: a header file that includes all the necessary libraries, function prototypes, and global variables.
main.c: the main file that contains the loop for getting the user input, parsing the input, and executing the command.
prompt.c: a file that handles the prompt display for the shell.
execute.c: a file that contains the functions for executing the non-built-in commands.
parser.c : This file contains the implementation of functions for parsing user input into arguments.
free.c: This file contains the implementation of functions for deallocating memory.
signal_handler.c: This file contains the implementation of signal handler functions for handling SIGINT, SIGTSTP and SIGQUIT signals.
builtins funcs: These are the source code files that contains functions related to the implementations of the built-in commands (cd, exit, env, setenv, unsetenv and help).
path funcs: These are the source code files that contains functions related to working with the system's PATH environment variable, such as finding a command in the PATH, getting the current PATH, and setting or modifying the PATH.
utils.c: a file that contains utility functions for the shell, such as string manipulation functions and functions for printing error messages.
error.c: This file contains the implementation of functions for handling errors.
Makefile: a file that specifies the compilation rules for the shell.
test_files: These are test files for each of the implementation files in source_files.
This tree separates the implementation files from the test files, making it easier to navigate the project and run the tests.
The header file declares several function prototypes for the shell program, including:
prompt(): prints the shell prompt
execute(): executes a command with arguments
get_line(): Read input from the standard input. Custom getline().
get_input(): Retrieves user input from stdin. Uses getline().
tokenize(): parsing user input into arguments.
handle_sigint(): signal handler for SIGINT
handle_sigstp(): signal handler for SIGSTP
handle_sigquit(): signal handler for SIGQUIT
check_for_builtin(): checks if a command is a shell builtin
shell_env(): prints environment variables
shell_setenv(): sets an environment variable
shell_unsetenv(): unsets an environment variable
shell_help(): prints help information for the shell
shell_cd(): changes the current working directory
shell_exit(): exits the shell program with a status code
_getenv(): retrieves the value of an environment variable
find_in_path(): searches for a command in the directories specified by the PATH environment variable
get_path(): retrieves the PATH environment variable
set_path(): sets the PATH environment variable
append_to_path(): appends a directory to the PATH environment variable
prepend_to_path(): prepends a directory to the PATH environment variable
free_error(): frees memory allocated following system error
free_tokens(): frees memory allocated for tokens
_puterror(): prints an error message
_puts(): prints a string
_atoi(): converts a string to an integer
_putchar(): prints a character
_strlen(): gets the length of a string
_strcmp(): compares two strings
_strcpy(): copies a string
_strcat(): concatenates two strings
_strdup(): duplicates a string
_strchr(): searches a string for a character
_strstr(): searches for the first occurrence of a substring
_strspn(): gets the length of a prefix substring
To use the simple shell, compile the files using gcc -Wall -Werror -Wextra -pedantic *.c -o hsh. Then, run the shell using ./hsh.
gcc -Wall -Werror -Wextra -pedantic *.c -o hsh
This wil compile all the '.c' files and change the output's name to 'hsh'.
=============
$ ./hsh
($) ls
hsh main.c shell.c shell.h
$ exit
$
also 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
$
To generate a man page for the simple_shell, you can use the ronn utility. ronn allows you to write man pages in Markdown format and then convert them to man page format.
Once you have created the simple_shell.1.md file, run the following command to generate the man page:
ronn simple_shell.1.md
This will create a new file called simple_shell.1. You can view the man page by running the following command:
man ./simple_shell.1
This program was written by FourtyThree43 and Kemboiray.
This project is licensed under the MIT License - see the LICENSE file for details.