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Josef and Tu's Shell

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Description

Josef and Tu's Shell is a simple UNIX command interpreter that replicates functionalities of the simple shell (sh). Additional functions are also included. This program was written entirely in C as a milestone project for Holberton School.

Installation

Clone this repository into your working directory. For best results, files should be compiled with GCC and the following flags: -Wall -Wextra -Werror -pedantic -Wno-format.

Usage

After compilation, the resulting program can run stand-alone, either in interactive or non-interactive mode.

Interactive Mode

In interactive mode, simply run the program and wait for the prompt to appear. From there, you can type commands freely, exiting with either the "exit" command or ctrl-D.

Non-Interactive Mode

In non-interactive mode, echo your desired command and pipe it into the program like this:

echo "ls" | ./shell

In non-interactive mode, the program will exit after finishing your desired command(s).

Included Built-Ins

Our shell has support for the following built-in commands:

Command Definition
exit [n] Exit the shell, with an optional exit status, n.
env Print the environment.
setenv [var][value] Set an environment variable and value. If the variable exists, the value will be updated.
unsetenv [var] Remove an environment variable.
cd [dir] Change the directory.
help [built-in] Read documentation for a built-in.

The following built-in commands may be supported in future versions:

Command Definition
alias Set an Alias.
history View the history of the shell.

Outside Programs

Our shell can run outside programs by typing their absolute paths (/bin/ls) or the executable name (ls), IF their directory is included in the PATH.

Examples

$ ls -l
total 8
drwxrwxr-x 1 vagrant vagrant Apr 2 13:23 directory_1
drwxrwxr-x 2 vagrant vagrant Apr 2 20:30 directory_2
$ /bin/pwd
/home/vagrant/shell
$ hello world
./hsh: 1: hello: not found
$ help env
env: env
	Print the environment.

Included Files

  • main.c - functions for calling the shell and initializing the shell struct
  • shell.c - functions for running the basic shell logic
  • shell_helpers.c - functions for helping the shell run
  • split_string.c - functions for splitting string from the user
  • string_helpers1.c - functions for manipulating strings
  • string_helpers2.c - functions for manipulating strings
  • built_ins.c - functions for built-ins
  • built_in_helpers.c - functions for helping the built-in functions
  • help.c - functions for the help built-in
  • help2.c - functions for the help built-in
  • cd.c - functions for the cd built-in
  • cd2.c - functions for the cd built-in
  • _getenv.c - functions for getting elements from the environment
  • env.c - functions for the env, setenv, and unsetenv built-ins
  • llfuncs1.c - linked list functions
  • llfuncs2.c - linked list functions
  • expansions.c - functions for dealing with the $? and $$ expansions
  • check_path.c - functions for checking the path of an executable
  • error_handler.c - functions for dealing with errors
  • free.c - functions for freeing allocated memory
  • holberton.h - header file

Credits

All code written by Tu Vo and Josef Goodyear.