Rake tasks

Your first task

Rake reads a file named Rakefile in the current directory and runs the requested task.

A task pairs a name with a block, and rake greet runs the block from the terminal.

task :greet do puts "Hello from Rake" end

rake greet

Hello from Rake

Describe tasks

The desc line documents the task below it for the task list.

Run rake -T to see every described task with its one line summary.

desc "Say hello" task :greet do puts "Hello from Rake" end

rake -T

rake greet # Say hello

Dependencies

Tasks declare prerequisites that run first, which models real build order.

Greet depends on prepare, so preparing always happens before greeting.

task :prepare do puts "Preparing" end task greet: :prepare do puts "Hello from Rake" end

rake greet

Preparing
Hello from Rake

Default task

The default task runs when the command names no task at all.

Point default at greet to make a bare rake call prepare and greet in order.

task :prepare do puts "Preparing" end task greet: :prepare do puts "Hello from Rake" end task default: :greet

rake

Preparing
Hello from Rake

Next: Environment and CLI

Article author: Arthur Isaev