7.3.10.1 Hello, World!

The first program we have to write, of course, is “Hello, World!”. This means that we have to implement a web handler that does what we want.

Now we define a handler, a function of two arguments and two return values:

(define (handler request request-body)
  (values response response-body))

In this first example, we take advantage of a short-cut, returning an alist of headers instead of a proper response object. The response body is our payload:

(define (hello-world-handler request request-body)
  (values '((content-type . (text/plain)))
          "Hello World!"))

Now let’s test it, by running a server with this handler. Load up the web server module if you haven’t yet done so, and run a server with this handler:

(use-modules (web server))
(run-server hello-world-handler)

By default, the web server listens for requests on localhost:8080. Visit that address in your web browser to test. If you see the string, Hello World!, sweet!

This document was generated on April 20, 2013 using texi2html 5.0.