racket Getting started with racket Find Racket sources in all subdirs

Example

#lang racket 
(for ([path (in-directory)]
  #:when (regexp-match? #rx"[.]rkt$" path))
  (printf "source file: ~a\n" path))

The #lang line specifies the programming language of this file. #lang racket we are using the baseline, battery-included Racket programming language. Other languages ranen from Racket flavors such as Type Racket (#lang typed/racket) or the documentation language Scribble (#lang scribble), to small convenience languages such as the language for defining packages (#lang info).

The in-directory function constructs a sequence that walks a directory tree (starting with the current directory, by default) and generates paths in the tree. The for form binds path to each path in the sequence, and regexp-match? applies a pattern to the path.

To run the example, install Racket, start DrRacket, paste the example program into the top area in DrRacket, and click the Run button. Alternatively, save the program to a file and run racket from the command line on the file.