The following example declares a piece of code to be written in Racket, and then prints the string
#lang racket "Hello, world!"
Racket code can either be run directly from the command line or on the DrRacket IDE. Typing
racket on the command line will start a REPL, and typing
racket followed by a file name will evaluate the contents of the file. For example, suppose the file
hello.rkt contains the above code. Here is an example of running Racket on the command line.
$ racket Welcome to Racket v6.5. > "Hello, world!" "Hello, world!" > (exit) $ racket hello.rkt "Hello, world!"