On this page
System.Process.Internals
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 |
Description
Note: This module exports internal implementation details that may change anytime. If you want a more stable API, use System.Process instead.
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.
On Windows a second wait method can be used to block for event completion. This requires two handles. A process job handle and a events handle to monitor.
Constructors
ProcessHandle | |
Fields
|
data ProcessHandle__ Source
Constructors
OpenHandle | |
Fields
|
|
OpenExtHandle | |
Fields
|
|
ClosedHandle ExitCode |
closePHANDLE :: PHANDLE -> IO () Source
mkProcessHandle :: PHANDLE -> Bool -> IO ProcessHandle Source
Instances
modifyProcessHandle :: ProcessHandle -> (ProcessHandle__ -> IO (ProcessHandle__, a)) -> IO a Source
withProcessHandle :: ProcessHandle -> (ProcessHandle__ -> IO a) -> IO a Source
data CreateProcess Source
Constructors
CreateProcess | |
Fields
|
Instances
Show CreateProcess Source | |
Defined in System.Process.Common MethodsshowsPrec :: Int -> CreateProcess -> ShowS Source show :: CreateProcess -> String Source showList :: [CreateProcess] -> ShowS Source |
|
Eq CreateProcess Source | |
Defined in System.Process.Common Methods(==) :: CreateProcess -> CreateProcess -> Bool (/=) :: CreateProcess -> CreateProcess -> Bool |
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
|
Instances
IsString CmdSpec Source | construct a Since: process-1.2.1.0 |
Defined in System.Process.Common MethodsfromString :: String -> CmdSpec Source |
|
Show CmdSpec Source | |
Eq CmdSpec Source | |
Constructors
Inherit | Inherit Handle from parent |
UseHandle Handle | Use the supplied Handle |
CreatePipe | Create a new pipe. The returned |
NoStream | Close the stream's file descriptor without passing a Handle. On POSIX systems this may lead to strange behavior in the child process because attempting to read or write after the file has been closed throws an error. This should only be used with child processes that don't use the file descriptor at all. If you wish to ignore the child process's output you should either create a pipe and drain it manually or pass a |
data ProcRetHandles Source
contains the handles returned by a call to createProcess_Internal
Constructors
ProcRetHandles | |
Fields
|
Arguments
:: String | Function name (for error messages). This can be any |
-> CreateProcess | |
-> IO (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle) |
This function is almost identical to createProcess
. The only differences are:
Handle
s provided viaUseHandle
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: process-1.2.1.0
Arguments
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
unwrapHandles :: ProcRetHandles -> (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle) Source
pPrPr_disableITimers :: IO () Source
c_execvpe :: CString -> Ptr CString -> Ptr CString -> IO CInt Source
runInteractiveProcess_lock :: MVar () Source
runInteractiveProcess
blocks signals around the fork(). Since blocking/unblocking of signals is a global state operation, we need to ensure mutual exclusion of calls to runInteractiveProcess
. This lock is exported so that other libraries which also need to fork() (and also need to make the same global state changes) can protect their changes with the same lock. See https://github.com/haskell/process/pull/154.
Since: process-1.6.6.0
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.
- WinIO Support
When this function is used with WinIO enabled it's the caller's responsibility to register the handles with the I/O manager. If this is not done the operation will deadlock. Association can be done as follows:
#if defined(IO_MANAGER_WINIO)
import GHC.IO.SubSystem ((!))
import GHC.IO.Handle.Windows (handleToHANDLE)
import GHC.Event.Windows (associateHandle')
#endif
...
#if defined (IO_MANAGER_WINIO)
return () ! (do
associateHandle' =handleToHANDLE <handle)
#endif
Only associate handles that you are in charge of read/writing to. Do not associate handles passed to another process. It's the process's reponsibility to register the handle if it supports async access.
Since: process-1.2.1.0
createPipeFd :: IO (FD, FD) Source
Create a pipe for interprocess communication and return a (readEnd, writeEnd)
FD
pair.
Since: process-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
© The University of Glasgow and others
Licensed under a BSD-style license (see top of the page).
https://downloads.haskell.org/~ghc/9.4.2/docs/libraries/process-1.6.15.0/System-Process-Internals.html