#!/usr/bin/env bash

PAGE=${PATH_INFO#*/}

if [ ! -z "$PAGE" ]; then
   echo -e 'Content-Type: text/plain\n'
   echo "$PAGE" | egrep '^[A-Za-z_.][A-Za-z_.-]*$' &> /dev/null
   if [ ! $? = 0 ]; then
      echo Invalid input: "$PAGE"
   else
      man "$PAGE" 2> /dev/null | col -b || \
         echo Sorry, there was an error.
   fi
else
   echo -e 'Content-Type: text/html\n'
   echo '<p>Try e.g. <a href="/man/cat">man cat</a>.</p>'
fi