Personal tools

Cookbook/Network programming

From HaskellWiki

< Cookbook(Difference between revisions)
Jump to: navigation, search
(add browser + proxy example)
Current revision (20:37, 26 May 2011) (edit) (undo)
m (fix up some weird formatting issues)
 
(2 intermediate revisions not shown.)
Line 3: Line 3:
<haskell>
<haskell>
-
import Network;
+
import Network
-
import System.IO;
+
import System.IO
-
main = withSocketsDo $ do
+
main = withSocketsDo $ do
-
h <- connectTo "www.google.com" (PortNumber 80)
+
h <- connectTo "www.google.com" (PortNumber 80)
-
hSetBuffering h LineBuffering
+
hSetBuffering h LineBuffering
-
hPutStr h "GET / HTTP/1.1\nhost: www.google.com\n\n"
+
hPutStr h "GET / HTTP/1.1\nhost: www.google.com\n\n"
-
contents <- hGetContents h
+
contents <- hGetContents h
-
putStrLn contents
+
putStrLn contents
-
hClose h
+
hClose h
</haskell>
</haskell>
-
The following example do a POST via a proxy
+
The following example POSTs via a proxy.
<haskell>
<haskell>
Line 22: Line 22:
import Network.Browser
import Network.Browser
-
Just pollUri = parseURI "http://example.com/question?life&universe&everything"
+
Just pollUri = parseURI "http://example.com/question?life&universe&everything" -- WARNING: only works with hardcoded arguments like this one
body = "answer=42"
body = "answer=42"
headers = [Header HdrContentType "application/x-www-form-urlencoded",
headers = [Header HdrContentType "application/x-www-form-urlencoded",

Current revision

The following example makes use of the Network and System.IO libraries to open a socket connection to Google and retrieve the Google home page. 

import Network
import System.IO
 
main = withSocketsDo $ do
    h <- connectTo "www.google.com" (PortNumber 80)
    hSetBuffering h LineBuffering
    hPutStr h "GET / HTTP/1.1\nhost: www.google.com\n\n"
    contents <- hGetContents h
    putStrLn contents
    hClose h

The following example POSTs via a proxy. 

import Network.URI
import Network.HTTP
import Network.Browser
 
Just pollUri = parseURI "http://example.com/question?life&universe&everything" -- WARNING: only works with hardcoded arguments like this one
body = "answer=42"
headers = [Header HdrContentType "application/x-www-form-urlencoded",
           Header HdrContentLength (show . length $ body)]
 
pollRq = Request {
 rqURI = pollUri, rqMethod = POST,
 rqHeaders = headers,
 rqBody = body
}
 
-- Default polipo setting
p = Proxy "localhost:8118" Nothing
 
main = browse $ do
     setProxy p
     request pollRq
Retrieved from "http://www.haskell.org/haskellwiki/Cookbook/Network_programming"