Provides a means of adding a Lua function as an input filter. As with output filters, input filters work as coroutines, first yielding before buffers are sent, then yielding whenever a bucket needs to be passed down the chain, and finally (optionally) yielding anything that needs to be appended to the input data. The global variable bucket holds the buckets as they are passed onto the Lua script:

LuaInputFilter myInputFilter "/www/filter.lua" input_filter
<Files "*.lua">
 SetInputFilter myInputFilter
</Files>

--[[
 Example input filter that converts all POST data to uppercase.
]]--
function input_filter(r)
 print("luaInputFilter called") -- debug print
 coroutine.yield() -- Yield and wait for buckets
 while bucket do -- For each bucket, do...
 local output = string.upper(bucket) -- Convert all POST data to uppercase
 coroutine.yield(output) -- Send converted data down the chain
 end
 -- No more buckets available.
 coroutine.yield("&filterSignature=1234") -- Append signature at the end
end

The input filter supports denying/skipping a filter if it is deemed unwanted:

function input_filter(r)
 if not good then
 return -- Simply deny filtering, passing on the original content instead
 end
 coroutine.yield() -- wait for buckets
 ... -- insert filter stuff here
end

See "Modifying contents with Lua filters" for more information.