unix-2.5.0.0: POSIX functionality

Portability	non-portable (requires POSIX)
Stability	provisional
Maintainer	libraries@haskell.org

System.Posix.Unistd

Contents

System environment
Sleeping

Description

POSIX miscellaneous stuff, mostly from unistd.h

Synopsis

data SystemID = SystemID {
- systemName :: String
- nodeName :: String
- release :: String
- version :: String
- machine :: String
}
getSystemID :: IO SystemID
data SysVar
- = ArgumentLimit
- | ChildLimit
- | ClockTick
- | GroupLimit
- | OpenFileLimit
- | PosixVersion
- | HasSavedIDs
- | HasJobControl
getSysVar :: SysVar -> IO Integer
sleep :: Int -> IO Int
usleep :: Int -> IO ()
nanosleep :: Integer -> IO ()

System environment

data SystemID Source

Constructors

Fields

systemName :: String
nodeName :: String
release :: String
version :: String
machine :: String

getSystemID :: IO SystemID Source

data SysVar Source

Constructors

getSysVar :: SysVar -> IO Integer Source

Sleeping

sleep :: Int -> IO Int Source

Sleep for the specified duration (in seconds). Returns the time remaining (if the sleep was interrupted by a signal, for example).

GHC Note: the comment for usleep also applies here.

usleep :: Int -> IO () Source

Sleep for the specified duration (in microseconds).

GHC Note: Control.Concurrent.threadDelay is a better choice. Without the -threaded option, usleep will block all other user threads. Even with the -threaded option, usleep requires a full OS thread to itself. Control.Concurrent.threadDelay has neither of these shortcomings.

nanosleep :: Integer -> IO () Source

Sleep for the specified duration (in nanoseconds)