| Copyright | (c) The University of Glasgow 2002 | 
|---|---|
| License | BSD-style (see the file libraries/base/LICENSE) | 
| Maintainer | libraries@haskell.org | 
| Stability | provisional | 
| Portability | non-portable (requires POSIX) | 
| Safe Haskell | Trustworthy | 
| Language | Haskell2010 | 
System.Posix.Env.ByteString
Description
POSIX environment support
Synopsis
- getEnv :: ByteString -> IO (Maybe ByteString)
 - getEnvDefault :: ByteString -> ByteString -> IO ByteString
 - getEnvironmentPrim :: IO [ByteString]
 - getEnvironment :: IO [(ByteString, ByteString)]
 - setEnvironment :: [(ByteString, ByteString)] -> IO ()
 - putEnv :: ByteString -> IO ()
 - setEnv :: ByteString -> ByteString -> Bool -> IO ()
 - unsetEnv :: ByteString -> IO ()
 - clearEnv :: IO ()
 - getArgs :: IO [ByteString]
 
Environment Variables
getEnv  looks up a variable in the environment.
getEnvDefault  is a wrapper around getEnv  where the
 programmer can specify a fallback as the second argument, which will be
 used if the variable is not found in the environment.
Arguments
getEnvironment  retrieves the entire environment as a
 list of (key,value) pairs.
setEnvironment  resets the entire environment to the given list of
 (key,value) pairs.
Since: 2.8.0.0
putEnv  function takes an argument of the form name=value
 and is equivalent to setEnv(key,value,True{-overwrite-}).
The setEnv  function inserts or resets the environment variable name in
 the current environment list. If the variable name does not exist in the
 list, it is inserted with the given value. If the variable does exist,
 the argument overwrite is tested; if overwrite is False, the variable is
 not reset, otherwise it is reset to the given value.
The unsetEnv  function deletes all instances of the variable name
 from the environment.
Program arguments
getArgs :: IO [ByteString] Source #
Computation getArgs  returns a list of the program's command
 line arguments (not including the program name), as ByteString s.
Unlike getArgs , this function does no Unicode
 decoding of the arguments; you get the exact bytes that were passed
 to the program by the OS. To interpret the arguments as text, some
 Unicode decoding should be applied.