jmatias/devcli

A command line tool to create command line tools.

devcli

devcli is a command line tool to create command line tools.

Creating your new tool

The first thing you need is to download devcli by cloning this repo and cd into it.

Start by calling devcli create -n TOOL_NAME -d DIR_TO_CREATE, where TOOL_NAME is how you want to call your new CLI tool. DIR_TO_CREATE is where you want it be be created. Example:

./devcli create -n mytool -d ~/Projects/myproject

Now, if you go to ~/Projects/myproject you should see the initial structure for your CLI. Take a look at the scripts to see examples of what you can do!

Extending your new tool

Any scripts added to the CLI directory will be available as commands to your tool. Check the template script to see an example of a simple command.

Let's create a new hello world command. Create a hello_world file (without .sh) and add the following to it:

#!/bin/bash

echo "Hello World"

Now, whe you run ./mytool hello_world you should see Hello World on your terminal!

For each command you might want to give the user some context on what it does and how to use it. To do that you'll just need to define two variable, one called SUBCOMMAND_DESC where you can give a shor description of your command and another called SUBCOMMAND_HELP for a more detailed explanation on what subcommands it takes, arguments that are required and environment variable that it uses.

For now edit your hello_world file to include the following right after #!/bin/bash:

SUBCOMMAND_DESC="Say Hello to the World!"
SUBCOMMAND_HELP=$(cat <<EOH

Say hello and enjoy your day!
EOH
)

Now, if you run ./mytool help you should get back the defined commands, including:

  hello_world:          Say Hello to the World!

If you run ./mytool hello_world help you'll get the more detailed version.

Helper functions

Some functions are defined right at mytool and are available to all your scripts.

As an example, let's see how to display information using a color schema:

in_red()      # use for failures
in_green()    # use for successes
in_yellow()   # use for warnings / attention
in_magenta()  # use for debug messages
in_cyan()     # use for main actions / progress

If you use in_cyan "Hello World" you'll see Hello World in cyan. Check that file out to see other useful functions.

You can also change that file to add your own helper functions

Helper files

If you want to have some functions that are shared accross other commands you can create a file with _ at the beginning, like _my_helper, and just put your functions there. Now other commands can use those functions by just including use 'my_helper'. Note that you don't need to prefix it with _!