System.Process.Internals

process-1.4.2.0: Process libraries

Copyright | (c) The University of Glasgow 2004
License | BSD-style (see the file libraries/base/LICENSE)
Maintainer | libraries@haskell.org
Stability | experimental
Portability | portable
Safe Haskell | Trustworthy
Language | Haskell2010

System.Process.Internals

Description

Note: This module exports internal implementation details that may change anytime. If you want a more stable API, use System.Process instead.

Synopsis

- data ProcessHandle = ProcessHandle !(MVar ProcessHandle__) !Bool
- data ProcessHandle__
  - = OpenHandle PHANDLE
  - | ClosedHandle ExitCode
- type PHANDLE = CPid
- closePHANDLE :: PHANDLE -> IO ()
- mkProcessHandle :: PHANDLE -> Bool -> IO ProcessHandle
- modifyProcessHandle :: ProcessHandle -> (ProcessHandle__ -> IO (ProcessHandle__, a)) -> IO a
- withProcessHandle :: ProcessHandle -> (ProcessHandle__ -> IO a) -> IO a
- data CreateProcess = CreateProcess {
  - cmdspec :: CmdSpec
  - cwd :: Maybe FilePath
  - env :: Maybe [(String, String)]
  - std_in :: StdStream
  - std_out :: StdStream
  - std_err :: StdStream
  - close_fds :: Bool
  - create_group :: Bool
  - delegate_ctlc :: Bool
  - detach_console :: Bool
  - create_new_console :: Bool
  - new_session :: Bool
  - child_group :: Maybe GroupID
  - child_user :: Maybe UserID
  }
- data CmdSpec
  - = ShellCommand String
  - | RawCommand FilePath [String]
- data StdStream
  - = Inherit
  - | UseHandle Handle
  - | CreatePipe
  - | NoStream
- createProcess_ :: String -> CreateProcess -> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
- runGenProcess_ :: String -> CreateProcess -> Maybe CLong -> Maybe CLong -> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)
- fdToHandle :: FD -> IO Handle
- startDelegateControlC :: IO ()
- endDelegateControlC :: ExitCode -> IO ()
- stopDelegateControlC :: IO ()
- pPrPr_disableITimers :: IO ()
- c_execvpe :: CString -> Ptr CString -> Ptr CString -> IO CInt
- ignoreSignal :: CLong
- defaultSignal :: CLong
- withFilePathException :: FilePath -> IO a -> IO a
- withCEnvironment :: [(String, String)] -> (Ptr CString -> IO a) -> IO a
- translate :: String -> String
- createPipe :: IO (Handle, Handle)
- createPipeFd :: IO (FD, FD)
- interruptProcessGroupOf :: ProcessHandle -> IO ()

# Documentation

data ProcessHandle Source #

Constructors

ProcessHandle !(MVar ProcessHandle__) !Bool |

data ProcessHandle__ Source #

A handle to a process, which can be used to wait for termination of the process using `waitForProcess`.

None of the process-creation functions in this library wait for termination: they all return a `ProcessHandle` which may be used to wait for the process later.

Constructors

OpenHandle PHANDLE |
ClosedHandle ExitCode |

type PHANDLE = CPid Source #

closePHANDLE :: PHANDLE -> IO () Source #

mkProcessHandle :: PHANDLE -> Bool -> IO ProcessHandle Source #

modifyProcessHandle :: ProcessHandle -> (ProcessHandle__ -> IO (ProcessHandle__, a)) -> IO a Source #

withProcessHandle :: ProcessHandle -> (ProcessHandle__ -> IO a) -> IO a Source #

data CreateProcess Source #

Constructors

CreateProcess |
Fields cmdspec :: CmdSpec Executable & arguments, or shell command cwd :: Maybe FilePath Optional path to the working directory for the new process env :: Maybe [(String, String)] Optional environment (otherwise inherit from the current process) std_in :: StdStream How to determine stdin std_out :: StdStream How to determine stdout std_err :: StdStream How to determine stderr close_fds :: Bool Close all file descriptors except stdin, stdout and stderr in the new process (on Windows, only works if std_in, std_out, and std_err are all Inherit) create_group :: Bool Create a new process group delegate_ctlc :: Bool Delegate control-C handling. Use this for interactive console processes to let them handle control-C themselves (see below for details). On Windows this has no effect. Since: 1.2.0.0 detach_console :: Bool Use the windows DETACHED_PROCESS flag when creating the process; does nothing on other platforms. Since: 1.3.0.0 create_new_console :: Bool Use the windows CREATE_NEW_CONSOLE flag when creating the process; does nothing on other platforms. Default: `False` Since: 1.3.0.0 new_session :: Bool Use posix setsid to start the new process in a new session; does nothing on other platforms. Since: 1.3.0.0 child_group :: Maybe GroupID Use posix setgid to set child process's group id; does nothing on other platforms. Default: `Nothing` Since: 1.4.0.0 child_user :: Maybe UserID Use posix setuid to set child process's user id; does nothing on other platforms. Default: `Nothing` Since: 1.4.0.0

data CmdSpec Source #

Constructors

ShellCommand String | A command line to execute using the shell
RawCommand FilePath [String] | The name of an executable with a list of arguments The `FilePath` argument names the executable, and is interpreted according to the platform's standard policy for searching for executables. Specifically: on Unix systems the execvp(3) semantics is used, where if the executable filename does not contain a slash (`/`) then the `PATH` environment variable is searched for the executable. on Windows systems the Win32 `CreateProcess` semantics is used. Briefly: if the filename does not contain a path, then the directory containing the parent executable is searched, followed by the current directory, then some standard locations, and finally the current `PATH`. An `.exe` extension is added if the filename does not already have an extension. For full details see the documentation for the Windows `SearchPath` API.

Instances

IsString CmdSpec # | construct a `ShellCommand` from a string literal Since: 1.2.1.0
Methods fromString :: String -> CmdSpec Source #

data StdStream Source #

Constructors

Inherit | Inherit Handle from parent
UseHandle Handle | Use the supplied Handle
CreatePipe | Create a new pipe. The returned `Handle` will use the default encoding and newline translation mode (just like `Handle`s created by `openFile`).
NoStream | No stream handle will be passed

createProcess_ Source #

Arguments

:: String | function name (for error messages)
-> CreateProcess |
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle) |

This function is almost identical to `createProcess`. The only differences are:

- `Handle`s provided via `UseHandle` are not closed automatically.
- This function takes an extra `String` argument to be used in creating error messages.

This function has been available from the System.Process.Internals module for some time, and is part of the System.Process module since version 1.2.1.0.

Since: 1.2.1.0

runGenProcess_ Source #

Arguments

:: String | function name (for error messages)
-> CreateProcess |
-> Maybe CLong | handler for SIGINT
-> Maybe CLong | handler for SIGQUIT
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle) |

Deprecated: Please do not use this anymore, use the ordinary `createProcess`. If you need the SIGINT handling, use delegate_ctlc = True (runGenProcess_ is now just an imperfectly emulated stub that probably duplicates or overrides your own signal handling).

fdToHandle :: FD -> IO Handle Source #

Turn an existing file descriptor into a Handle. This is used by various external libraries to make Handles.

Makes a binary Handle. This is for historical reasons; it should probably be a text Handle with the default encoding and newline translation instead.

startDelegateControlC :: IO () Source #

endDelegateControlC :: ExitCode -> IO () Source #

stopDelegateControlC :: IO () Source #

pPrPr_disableITimers :: IO () Source #

c_execvpe :: CString -> Ptr CString -> Ptr CString -> IO CInt Source #

ignoreSignal :: CLong Source #

defaultSignal :: CLong Source #

withFilePathException :: FilePath -> IO a -> IO a Source #

withCEnvironment :: [(String, String)] -> (Ptr CString -> IO a) -> IO a Source #

translate :: String -> String Source #

createPipe :: IO (Handle, Handle) Source #

Create a pipe for interprocess communication and return a `(readEnd, writeEnd)` `Handle` pair.

Since: 1.2.1.0

createPipeFd :: IO (FD, FD) Source #

Create a pipe for interprocess communication and return a `(readEnd, writeEnd)` `FD` pair.

Since: 1.4.2.0

interruptProcessGroupOf Source #

Arguments

:: ProcessHandle | A process in the process group
-> IO () |

Sends an interrupt signal to the process group of the given process.

On Unix systems, it sends the group the SIGINT signal.

On Windows systems, it generates a CTRL_BREAK_EVENT and will only work for processes created using `createProcess` and setting the `create_group` flag