Std.IO.StdStream

This module provides stdin/stderr/stdout reading and writings. Usually you don't have to use stderr or stderrBuf directly, Logger provides more logging utilities through stderr. While stdinBuf and stdoutBuf is useful when you write interactive programs, Buffered module provide many reading and writing operations. Example:

import Std.IO.LowResTimer
import Std.IO.Buffered
import Std.IO.StdStream

main = do
    -- read by '\n'
    b1 <- readLineStd
    -- read whatever user input in 3s, otherwise get Nothing
    b2 <- timeoutLowRes 30 $ readBuffered stdinBuf
    ...
    putStd "hello world!"

Standard input & output streams

data StdStream

Standard input and output streams

We support both regular file and TTY based streams, when initialized uv_guess_handle is called to decide which type of devices are connected to standard streams.

StdStream is different from other UVStream in that exception during reading & writing won't close StdStream.

Instances

Output StdStream

Defined in Std.IO.StdStream

Methods

writeOutput :: StdStream -> Ptr Word8 -> Int -> IO ()

Input StdStream

Defined in Std.IO.StdStream

Methods

readInput :: StdStream -> Ptr Word8 -> Int -> IO Int

isStdStreamTTY :: StdStream -> Bool

stdin :: StdStream

stdout :: StdStream

stderr :: StdStream

stdinBuf :: BufferedInput StdStream

stdoutBuf :: BufferedOutput StdStream

utils

printStd :: Show a => a -> IO ()

print a Show to stdout

readLineStd :: IO Bytes

read a line from stdin

putStd :: Builder a -> IO ()

print a Builder and flush to stdout.

putLineStd :: Builder a -> IO ()

print a Builder and flush to stdout stdout, with a linefeed.