Your first Ruby script

What it is

A scriptA text file of commands that runs them in order, so a task you repeat becomes one command. is a text file with commands in it. You write it once, and from then on one command runs all of them, in order, every time the same way. WolOS runs scripts written for the shell and scripts written in RubyA programming language known for reading almost like English. WolOS runs Ruby scripts the same way as shell scripts., a programming language that reads almost like English. Ruby is part of every WolOS, so there is nothing to install.

Two commands do everything on this page:

• wol script check reads a script and tells you about mistakes without running any of it;
• wol script run runs it.

Why WolOS does it this way

A script runs with your permissions, and scripts are often copied from somewhere. So WolOS runs every script the same careful way. It never runs one as rootThe system's own all-powerful account. You never sign in as root; a change that needs it asks for an administrator's password.. It hands your arguments to the script exactly as you typed them. It leaves the passwords and keys your terminal may hold out of the script's reach. And when a script asks WolOS to change something (a setting, an app, Do Not Disturb), you see a sheetA small window that asks you to confirm something before it happens, for example Allow or Deny, or your password. on screen first and decide, just as for any helperA script or AI assistant that changes WolOS for you through wol. Every change it makes is shown on screen for you to allow first.. Every run is written down in System Settings > Assistants & Automation, so you can see later what ran and when.

How

1. Write the script

Open Text Editor (Search: "text"), and type:

#!/usr/bin/env ruby
# Greets you and says how many files are in a folder.
# How: wol script run hello.rb Documents
# frozen_string_literal: true

folder = ARGV.fetch(0, 'Documents')
path = File.join(Dir.home, folder)
count = Dir.children(path).length
puts "Hello, #{ENV.fetch('USER')}!"
puts "#{folder} holds #{count} files and folders."

Save it in your home folder as hello.rb.

What each line does:

2. Check it

Open a terminal (Super+Return) and type:

wol script check hello.rb

When everything is right you see one line:

hello.rb: ruby script, parses and rubocop is clean

Parses means Ruby understood every line. Rubocop is clean means the style checker found nothing to improve; it comes with the Developer module, and without it the check reads the script only. Nothing in the script ran.

If something is wrong, you see one sentence per problem, with the line and the column of the file above it. Fix the line in Text Editor, save, and check again.

3. Run it

wol script run hello.rb Pictures

You see:

Hello, aliceliddell!
Pictures holds 12 files and folders.

Pictures was handed to the script as its first argument. Without it, the script counts Documents.

4. Let it change something, with your say-so

Scripts become useful when they act. Add these lines at the end of hello.rb:

system('wol', 'focus', 'on', exception: true)
puts 'Do Not Disturb is on.'

Run it again. Because the script now asks WolOS to turn on Do Not DisturbA switch that keeps banners off the screen. Notifications still arrive and wait in Notification Center., a sheet appears and names the script (script:hello.rb) and what it wants to do. Click Allow Once, and the script continues. Deny stops that change, and the script stops with an error. Always Allow lets this script do this kind of change from now on without asking; you can take that back in System Settings > Assistants & Automation.

5. See what ran

System Settings > Assistants & Automation lists every script run: which script, when, and how it ended. The arguments are not listed, because they may hold private words.

What a script may and may not do

A worked example

Alice wants a quiet hour while she backs up her photos. She writes backup.rb:

#!/usr/bin/env ruby
# Turns Do Not Disturb on while it makes a copy of a folder.
# How: wol script run backup.rb Pictures
# frozen_string_literal: true

folder = ARGV.fetch(0)
system('wol', 'focus', 'on', exception: true)
system('tar', 'czf', "#{folder}.tar.gz", '-C', Dir.home, folder, exception: true)
puts "Saved #{folder}.tar.gz"

wol script check backup.rb says it parses. wol script run backup.rb Pictures shows the sheet for Do Not Disturb; she clicks Always Allow, and the copy Pictures.tar.gz appears in the folder she ran it from. Next Sunday she runs the same line again, and this time no sheet appears.

If something goes wrong

The Scripts and shells page goes further: shell scripts, running a script on another computer, and choosing the shell of your terminal.