scwrypts/zsh

ZSH Scwrypts

Since they emulate direct user interaction, shell scripts are a (commonly dreaded) go-to for automation.

Although the malleability of shell scripts can make integrations quickly, the ZSH-type scwrypt provides a structure to promote extendability and clean code while performing a lot of the heavy lifting to ensure consistent execution across different runtimes.

The Basic Framework

Take a look at the simplest ZSH-type scwrypt: hello-world. The bare minimum API for ZSH-type scwrypts is to:

1. include the shebang #!/usr/bin/env zsh on the first line of the file
2. wrap your zsh in a function called MAIN()
3. make the file executable (e.g. chmod +x hello-world)

Once this is complete, you are free to simply write valid zsh then execute the scwrypt with scwrypts hello world zsh!

Basics+

While it would be perfectly fine to use the echo function in our scwrypt, you'll notice that the hello-world scwrypt instead uses echo.success which is not valid ZSH by default. This is a helper function provided by the scwrypts ZSH library, and it does a lot more work than you'd expect.

Although this function defaults to print user messages in color, notice what happens when you run scwrypts --output json hello world zsh:

{"timestamp":1745674060,"runtime":"c62737da-481e-4013-a370-4dedc76bf4d2","scwrypt":"start of hello-world scwrypts zsh","logLevel":"3","subscwrypt":0}
{"timestamp":1745674060,"runtime":"c62737da-481e-4013-a370-4dedc76bf4d2","status":"SUCCESS","message":"\"Hello, World!\""}
{"timestamp":1745674060,"runtime":"c62737da-481e-4013-a370-4dedc76bf4d2","status":"SUCCESS","message":"\"terminated with code 0\""}

We get a LOT more information.

It's 100% possible for you to include your own take on printing messages, but it is highly recommended to use the tools provided here.

What is loaded by default?

By default, every ZSH-type scwrypt will load the basic utilities suite, which is a little different from scwrypts ZSH modules, and a little bit complex. Although it's totally worth a deep-dive, here are the fundamentals you should ALWAYS use:

Printing User Messages or Logs

Whenever you want to print a message to the user or logs, rather than using echo, use the following:

function name	minimum log level	description
echo.success	1	indicate successful completion
echo.error	1	indicate an error has occurred
echo.reminder	1	an important, information message
echo.status	2	a regular, information message
echo.warning	3	a non-critical warning
echo.debug	4	a message for scwrypt developers

Of the echo family, there are two unique functions:

• echo.error will increment the ERRORS variable then return an error code of $ERRORS (this makes it easy to chain with command failure by using ||)
• echo.debug will inject state information like the timestamp and current function stack

Yes / No Prompts

The two helpers user.Yn and user.yN take a user-friendly yes/no question as an argument.

• when the user responds "yes", the command returns 0 / success / &&
• when the user responds "no", the command returns 1 / error / ||
• when the user responds with nothing (e.g. just presses enter), the default is used

The two commands work identically; however, the capitalization denotes the default:

• user.Yn = default "yes"
• user.yN = default "no"

Select from a List Prompt

When you want the user to select an item from a list, scwrypts typically use fzf. There are a LOT of options to fzf, so there are two provided helpers.

The basic selector, utils.fzf (most of the time, you want to use this one) which outputs:

• the selection if the user made a choice
• nothing / empty string if the user cancelled or made an invalid choice

The user-input selector, utils.fzf.user-input which outputs:

• the selection if the user made a choice
• the text typed by the user if the user typed something other than the listed choices
• nothing / empty string if the user cancelled
• a secondary utils.fzf prompt if the user's choice was ambiguous

Imports

Don't use source in ZSH-type scwrypts (I mean, if you're pretty clever you can get it to work, but DON'T THOUGH). Instead, use use!

The use command, rather than specifying file directories, you reference the path to *.module.zsh. This means you don't have to know the exact path to any given file. For example, if I wanted to import the safety tool for aws CLI commands, I can do the following:

#!/usr/bin/env zsh

use cloud/aws

#####################################################################

MAIN() {
    cloud.aws sts get-caller-identity
}