Smash Shell Version 1.2

Welcome to the Smash Shell! Below you will find a comprehensive guide on how to use the internal commands supported by the shell.

• Note: All standard Linux commands are also supported alongside these built-in commands.

Built-in Commands

cd [DIRECTORY]

Change the current working directory.

• DIRECTORY: The path to the desired directory. If no argument is provided, it will print an error.

exit

Exit the shell.

help

Displays a list of all built-in commands and a short description about the shell.

cwd

Print the current working directory.

clear

Clear the terminal screen.

echo [ARGUMENTS...]

Print the arguments to the terminal.

• ARGUMENTS: A list of arguments you want to echo. Each argument is printed on a new line.

showvar [VARIABLE_NAME]

Display the value of shell variables.

• VARIABLE_NAME: Optional. If specified, it will display the value of the given variable, otherwise, it will list all the shell variables with their values.

showenv [ENVIRONMENT_VARIABLES...]

Display the value of environment variables.

• ENVIRONMENT_VARIABLES: Optional. If not provided, it will print all the environment variables. If specific environment variables are provided, it will print their values.

export VARIABLE_NAME

Export the value of a shell variable to the environment.

unset VARIABLE_NAME

Unset a shell variable and also remove it from the environment.

alias [-n ALIAS_NAME ALIAS_VALUE] [-r ALIAS_NAME]

Manage command aliases.

• -n: Create a new alias. Requires both ALIAS_NAME and ALIAS_VALUE.
• -r: Remove an existing alias. Requires ALIAS_NAME.

Other Features

• Variable Expansion: If a variable is denoted with a $, the shell will expand it to its value, unless it's enclosed in double quotes.
• Variable Reassignment: If you assign a value to a variable using =, it will update the shell variable's value or create a new one if it doesn't exist.
• Pipeline Execution: Use | to pipe the output of one command to another.

Example

$ echo "Hello, World!"
Hello, World!

$ showenv PATH
/usr/local/bin:/usr/bin:/bin

$ alias -n ls "ls -al"
$ ls
(total files... in detailed list format...)