How to get the HTTP response headers in Rebol3?

Question

The read and write commands in Rebol, when passed a URL! parameter, can get you either a binary response or an error. So in the "one-off" style of doing a GET or a POST there is nowhere to get the response headers from.

result: read http://www.rebol.com

In this post about how to do it in Rebol2, it suggests you have to open a port! and get it from the port's local/headers field:

Rebol - HTTP response headers

This works in Rebol2, for instance

hp: open http://www.rebol.com
result: read hp
probe hp/locals/headers/Content-Encoding

But in Rebol3, when I open a port and try this the locals field of the port is empty. How to achieve the same behavior in Rebol3?

score 2 · Answer 1 · answered Jan 20 '14 at 05:01

One (long-winded) solution:

target: http://www.rebol.com/
port: make port! target
; make alterations to port/spec here, e.g.
; port/spec/method -- HTTP method
; port/spec/headers -- [set-word value] block of headers
; port/spec/content -- content
port/awake: func [event][
    switch event/type [
        connect [read event/port false]
        done [true]
    ]
]
open port
response: query port
wait [port 1]
close port
probe response

score 2 · Accepted Answer · answered Apr 05 '14 at 08:21

Is this what you're looking for?

>> hp: open http://www.rebol.com/
>> to string! read hp
== {<!doctype html>
<html><head>
<meta name="generator" content="REBOL WIP Wiki"/>
<meta name="date" content="16-Feb-2014/15:58:59-8:00"/>
<meta name="rebol-version" content="2.100.97.4.2"/>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8"/>
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="-1" />
<meta http-equiv="Cache-Control" content="no-cache" />
<meta name="Description" content="REBOL: a lightweight computer language with ad
vanced semantics. ...

>> query hp
== make object! [
    name: %/
    size: 7118
    date: none
    type: 'file
    response-line: "HTTP/1.1 200 OK"
    response-parsed: 'ok
    headers: make object! [
        Content-Length: 7118
        Transfer-Encoding: none
        Last-Modified: "Sun, 16 Feb 2014 23:58:59 GMT"
        Date: "Sat, 05 Apr 2014 08:19:34 GMT"
        Server: "Apache"
        Accept-Ranges: "bytes"
        Connection: "close"
        Content-Type: "text/html"
    ]
]

How to get the HTTP response headers in Rebol3?

2 Answers2