gistfile1.hs

import System.Process
import GHC.IO.Handle
import Text.Blaze.Html (Html)
import Text.Blaze.Html.Renderer.Utf8 (renderHtml)
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL


convertHtml :: Html -> IO B.ByteString
convertHtml html = do
    (Just stdin, Just stdout, _, _) <- createProcess $
        (wkhtmltopdf ["-", "-"]) { std_out = CreatePipe
                                 , std_in  = CreatePipe 
                                 }

    BL.hPutStr stdin (renderHtml html) >> hClose stdin
    B.hGetContents stdout