Editing WaSh (section)

== Random Jottings on WASH ==

Remember all programs must be precompiled with wash2hs before compilation with ghc (there may be some tools to automate this; where?). The executable produced by ghc can be moved to cgi-bin and accessed by the browser with http://localhost/cgi-bin/executableName.

=== Hello world programme ===
from [http://www.informatik.uni-freiburg.de/~thiemann/WASH/user-manual.pdf draft user manual], tweaked to work with [http://www.informatik.uni-freiburg.de/~thiemann/WASH/WashNGo-2.10.tgz version 2.10 of 20061206]

<haskell>
module Main where
import WASH.CGI.CGI hiding (div, head, map, span)
main =
  run mainCGI

mainCGI =
  ask <html>
          <head><title>Hello World</title></head>
          <body>
          <h1>Hello World</h1>
          </body>
       </html>

</haskell>

Compile with <code>ghc -pgmF wash2hs -package WashNGo --make Main</code>.


=== SELinux ===
To run ghc-compiled WASH CGI on Fedora (Core 6) you need to build an SELinux policy that allows CGI scripts to execute memory (because ghc runtime system execs mem).

<pre>
cat <<EOF > local.te
module local 1.0;

require {
        class process execmem;
        type httpd_sys_script_t; 
        role system_r; 
};

allow httpd_sys_script_t self:process execmem;
EOF

checkmodule -M -m -o local.mod local.te
semodule_package -o local.pp -m local.mod
su -c 'semodule -i local.pp'

</pre>