Network.CGI.Protocol

An implementation of the program side of the CGI protocol.

CGI request

data CGIRequest

The input to a CGI action.

Constructors

CGIRequest

Fields

• cgiVars :: Map String String

  Environment variables.

• cgiInputs :: [(String, Input)]

  Input parameters. For better laziness in reading inputs, this is not a Map.

• cgiRequestBody :: ByteString

  Raw request body. To avoid memory leaks, this is the empty string if the request body has been interpreted as inputs in "application/x-www-form-urlencoded" or "multipart/form-data" format.

Instances

Show CGIRequest

Methods

showsPrec :: Int -> CGIRequest -> ShowS

show :: CGIRequest -> String

showList :: [CGIRequest] -> ShowS

data Input

The value of an input parameter, and some metadata.

Constructors

Input

Fields

• inputValue :: ByteString
• inputFilename :: Maybe String
• inputContentType :: ContentType

Instances

Show Input

Methods

showsPrec :: Int -> Input -> ShowS

show :: Input -> String

showList :: [Input] -> ShowS

CGI response

data CGIResult

The result of a CGI program.

Constructors

CGIOutput ByteString

CGINothing

Instances

Eq CGIResult

Methods

(==) :: CGIResult -> CGIResult -> Bool

(/=) :: CGIResult -> CGIResult -> Bool

Ord CGIResult

Methods

compare :: CGIResult -> CGIResult -> Ordering

(<) :: CGIResult -> CGIResult -> Bool

(<=) :: CGIResult -> CGIResult -> Bool

(>) :: CGIResult -> CGIResult -> Bool

(>=) :: CGIResult -> CGIResult -> Bool

max :: CGIResult -> CGIResult -> CGIResult

min :: CGIResult -> CGIResult -> CGIResult

Read CGIResult

Methods

readsPrec :: Int -> ReadS CGIResult

readList :: ReadS [CGIResult]

readPrec :: ReadPrec CGIResult

readListPrec :: ReadPrec [CGIResult]

Show CGIResult

Methods

showsPrec :: Int -> CGIResult -> ShowS

show :: CGIResult -> String

showList :: [CGIResult] -> ShowS

type Headers = [(HeaderName, String)]

HTTP headers.

newtype HeaderName :: *

A string with case insensitive equality and comparisons.

Constructors

HeaderName String

Instances

Eq HeaderName

Methods

(==) :: HeaderName -> HeaderName -> Bool

(/=) :: HeaderName -> HeaderName -> Bool

Ord HeaderName

Methods

compare :: HeaderName -> HeaderName -> Ordering

(<) :: HeaderName -> HeaderName -> Bool

(<=) :: HeaderName -> HeaderName -> Bool

(>) :: HeaderName -> HeaderName -> Bool

(>=) :: HeaderName -> HeaderName -> Bool

max :: HeaderName -> HeaderName -> HeaderName

min :: HeaderName -> HeaderName -> HeaderName

Show HeaderName

Methods

showsPrec :: Int -> HeaderName -> ShowS

show :: HeaderName -> String

showList :: [HeaderName] -> ShowS

Running CGI actions

hRunCGI

Arguments

:: MonadIO m

=> [(String, String)]

CGI environment variables, e.g. from getCGIVars.

-> Handle

Handle that input will be read from, e.g. stdin.

-> Handle

Handle that output will be written to, e.g. stdout.

-> (CGIRequest -> m (Headers, CGIResult))

CGI action

-> m ()

Runs a CGI action in a given environment. Uses Handles for input and output.

runCGIEnvFPS

Arguments

:: Monad m

=> [(String, String)]

CGI environment variables.

-> ByteString

Request body.

-> (CGIRequest -> m (Headers, CGIResult))

CGI action.

-> m ByteString

Response (headers and content).

Runs a CGI action in a given environment. Uses lazy ByteStrings for input and output.

Inputs

decodeInput

Arguments

:: [(String, String)]

CGI environment variables.

-> ByteString

Request body.

-> ([(String, Input)], ByteString)

A list of input variables and values, and the request body if it was not interpreted.

Gets and decodes the input according to the request method and the content-type.

takeInput

Arguments

:: [(String, String)]

CGI environment variables.

-> ByteString

Request body.

-> ByteString

CONTENT_LENGTH bytes from the request body, or the empty string if there is no CONTENT_LENGTH.

Takes the right number of bytes from the input.

Environment variables

getCGIVars :: MonadIO m => m [(String, String)]

Gets the values of all CGI variables from the program environment.

Logging

logCGI :: MonadIO m => String -> m ()

Logs some message using the server's logging facility. FIXME: does this have to be more general to support FastCGI etc? Maybe we should store log messages in the CGIState?

URL encoding

formEncode :: [(String, String)] -> String

Formats name-value pairs as application/x-www-form-urlencoded.

urlEncode :: String -> String

Converts a single value to the application/x-www-form-urlencoded encoding.

formDecode :: String -> [(String, String)]

Gets the name-value pairs from application/x-www-form-urlencoded data.

urlDecode :: String -> String

Converts a single value from the application/x-www-form-urlencoded encoding.

Utilities

maybeRead :: Read a => String -> Maybe a

replace

Arguments

:: Eq a

=> a

Value to look for

-> a

Value to replace it with

-> [a]

Input list

-> [a]

Output list

Replaces all instances of a value in a list by another value.