/my_shell

Primary LanguageC

#my_zsh

my_zsh is a naive implementation of the Z-shell.

build

Build:

make

Clean

make clean

Run

./bin/my_zsh

Or

make run

Run

The following commands are built-in to the shell: cd, which, env, setenv, unsetenv, pwd, exit and echo. All binaries in your $PATH are also available for execution.

The shell allows for setting environment varibles using literals such as variable=value:

    user - /home/dev %> USER=khalil PWD=/home EDITOR=vim 
    khalil - /home   %> echo $EDITOR
    vim

String literal and interpolation is supported when using the echo command like so:

    user - /home/dev %>name=John age=41 city=Lagos
    user - /home/dev %>echo "My name is $name and I am from $city. I have $age years old."
    My name is John and I am from Lagos. I have 41 years old.

String literals and interpolation, however, are not available for assignment like so var="$PWD".

env

Synopsis:

    env [options [key=pair]... [command [args]

When a command is provided, env runs the specified program with the current shell's environment.
When not provided, env prints the environment to stdout.

The environment can be modified by passing key=pair. env accepts as many key=pair as necessary and will update a variable if already existing in the environment. You can test this command using ./bin/printenvs. This is a simple program that prints an incoming environment for testing purposes.

    env PWD=/home my_var=something ./bin/printenvs

Additionally, the following options are also available:

     -i, --ignore-enviroment

env produces an empty environment.

    -u [key]...

Unsets the avaiable with the provided key. At least one key must be provided.

    -0, --null

Prints the environment without the line break (\n). This options will not execute the command.

    -C [path]

This options runs the command from the path directory as opposed to shells $PWD directory. Example:

    user - /home/dev %> ls  
    project1   clang   rust     ruby
    user - /home/dev %>env -C /home ls  
    photos   dev  dotfiles   downloads   desktop

setenv

With this command you can set variables in the shells environment. setenv accepts both key=pair or key pair syntax.

    setenv PWD=/home USER=Joe PATH=/usr/bin

The below syntax is also allowed:

    setenv PWD /home USER Joe PATH /usr/bin

unsetenv

unsetenv as the name suggests, unsets a variable of a given key.

     unsetenv USER TERMINAL