Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Streaming.Process

Contents

Functions
Specialized streaming types
Process handle
Type classes
Checked processes
Reexport

Description

A full tutorial for this module is available at: https://github.com/snoyberg/conduit/blob/master/PROCESS.md .

Note that, while the tutorial covers Data.Conduit.Process , that module closely follows the present one, and almost all concepts in the tutorial apply here.

Synopsis

streamingProcess :: ( MonadIO m, InputSource stdin, OutputSink stdout, OutputSink stderr) => CreateProcess -> m (stdin, stdout, stderr, StreamingProcessHandle )
closeStreamingProcessHandle :: MonadIO m => StreamingProcessHandle -> m ()
data Inherited = Inherited
data ClosedStream = ClosedStream
data UseProvidedHandle = UseProvidedHandle
data StreamingProcessHandle
waitForStreamingProcess :: MonadIO m => StreamingProcessHandle -> m ExitCode
waitForStreamingProcessSTM :: StreamingProcessHandle -> STM ExitCode
getStreamingProcessExitCode :: MonadIO m => StreamingProcessHandle -> m ( Maybe ExitCode )
getStreamingProcessExitCodeSTM :: StreamingProcessHandle -> STM ( Maybe ExitCode )
streamingProcessHandleRaw :: StreamingProcessHandle -> ProcessHandle
streamingProcessHandleTMVar :: StreamingProcessHandle -> TMVar ExitCode
class InputSource a
class OutputSink a
withCheckedProcess :: ( InputSource stdin, OutputSink stderr, OutputSink stdout, MonadIO m) => CreateProcess -> (stdin -> stdout -> stderr -> m b) -> m b
data ProcessExitedUnsuccessfully = ProcessExitedUnsuccessfully CreateProcess ExitCode
module System.Process

Functions

streamingProcess :: ( MonadIO m, InputSource stdin, OutputSink stdout, OutputSink stderr) => CreateProcess -> m (stdin, stdout, stderr, StreamingProcessHandle ) Source #

The primary function for running a process. Note that, with the exception of UseProvidedHandle , the values for std_in , std_out and std_err will be ignored by this function.

Since 0.1.4

closeStreamingProcessHandle :: MonadIO m => StreamingProcessHandle -> m () Source #

Free any resources (e.g. Handle s) acquired by a call to streamingProcess .

Since: 0.1.16

Specialized streaming types

data Inherited Source #

Inherit the stream from the current process.

Since 0.1.4

Constructors

Inherited

Instances

Instances details

OutputSink Inherited Source #
Instance details Defined in Data.Streaming.Process Methods osStdStream :: ( Maybe Handle -> IO Inherited , Maybe StdStream ) Source #
InputSource Inherited Source #
Instance details Defined in Data.Streaming.Process Methods isStdStream :: ( Maybe Handle -> IO Inherited , Maybe StdStream ) Source #

data ClosedStream Source #

Close the stream with the child process.

You usually do not want to use this, as it will leave the corresponding file descriptor unassigned and hence available for re-use in the child process.

Since 0.1.4

Constructors

ClosedStream

Instances

Instances details

OutputSink ClosedStream Source #
Instance details Defined in Data.Streaming.Process Methods osStdStream :: ( Maybe Handle -> IO ClosedStream , Maybe StdStream ) Source #
InputSource ClosedStream Source #
Instance details Defined in Data.Streaming.Process Methods isStdStream :: ( Maybe Handle -> IO ClosedStream , Maybe StdStream ) Source #

data UseProvidedHandle Source #

Use the Handle provided by the CreateProcess value. This would allow you, for example, to open up a Handle to a file, set it as std_out , and avoid any additional overhead of dealing with providing that data to your process.

Since 0.1.4

Constructors

UseProvidedHandle

Instances

Instances details

OutputSink UseProvidedHandle Source #
Instance details Defined in Data.Streaming.Process Methods osStdStream :: ( Maybe Handle -> IO UseProvidedHandle , Maybe StdStream ) Source #
InputSource UseProvidedHandle Source #
Instance details Defined in Data.Streaming.Process Methods isStdStream :: ( Maybe Handle -> IO UseProvidedHandle , Maybe StdStream ) Source #

Process handle

data StreamingProcessHandle Source #

Wraps up the standard ProcessHandle to avoid the waitForProcess deadlock. See the linked documentation from the module header for more information.

Since 0.1.4

waitForStreamingProcess :: MonadIO m => StreamingProcessHandle -> m ExitCode Source #

Blocking call to wait for a process to exit.

Since 0.1.4

waitForStreamingProcessSTM :: StreamingProcessHandle -> STM ExitCode Source #

STM version of waitForStreamingProcess .

Since 0.1.4

getStreamingProcessExitCode :: MonadIO m => StreamingProcessHandle -> m ( Maybe ExitCode ) Source #

Non-blocking call to check for a process exit code.

Since 0.1.4

getStreamingProcessExitCodeSTM :: StreamingProcessHandle -> STM ( Maybe ExitCode ) Source #

STM version of getStreamingProcessExitCode .

Since 0.1.4

streamingProcessHandleRaw :: StreamingProcessHandle -> ProcessHandle Source #

Get the raw ProcessHandle from a StreamingProcessHandle . Note that you should avoid using this to get the process exit code, and instead use the provided functions.

Since 0.1.4

streamingProcessHandleTMVar :: StreamingProcessHandle -> TMVar ExitCode Source #

Get the TMVar storing the process exit code. In general, one of the above functions should be used instead to avoid accidentally corrupting the variable's state..

Since 0.1.4

Type classes

class InputSource a Source #

Class for all things which can be used to provide standard input.

Since 0.1.4

Minimal complete definition

isStdStream

Instances

Instances details

InputSource Handle Source #
Instance details Defined in Data.Streaming.Process.Internal Methods isStdStream :: ( Maybe Handle -> IO Handle , Maybe StdStream ) Source #
InputSource ClosedStream Source #
Instance details Defined in Data.Streaming.Process Methods isStdStream :: ( Maybe Handle -> IO ClosedStream , Maybe StdStream ) Source #
InputSource Inherited Source #
Instance details Defined in Data.Streaming.Process Methods isStdStream :: ( Maybe Handle -> IO Inherited , Maybe StdStream ) Source #
InputSource UseProvidedHandle Source #
Instance details Defined in Data.Streaming.Process Methods isStdStream :: ( Maybe Handle -> IO UseProvidedHandle , Maybe StdStream ) Source #

class OutputSink a Source #

Class for all things which can be used to consume standard output or error.

Since 0.1.4

Minimal complete definition

osStdStream

Instances

Instances details

OutputSink Handle Source #
Instance details Defined in Data.Streaming.Process.Internal Methods osStdStream :: ( Maybe Handle -> IO Handle , Maybe StdStream ) Source #
OutputSink ClosedStream Source #
Instance details Defined in Data.Streaming.Process Methods osStdStream :: ( Maybe Handle -> IO ClosedStream , Maybe StdStream ) Source #
OutputSink Inherited Source #
Instance details Defined in Data.Streaming.Process Methods osStdStream :: ( Maybe Handle -> IO Inherited , Maybe StdStream ) Source #
OutputSink UseProvidedHandle Source #
Instance details Defined in Data.Streaming.Process Methods osStdStream :: ( Maybe Handle -> IO UseProvidedHandle , Maybe StdStream ) Source #

Checked processes

withCheckedProcess :: ( InputSource stdin, OutputSink stderr, OutputSink stdout, MonadIO m) => CreateProcess -> (stdin -> stdout -> stderr -> m b) -> m b Source #

Run a process and supply its streams to the given callback function. After the callback completes, wait for the process to complete and check its exit code. If the exit code is not a success, throw a ProcessExitedUnsuccessfully .

NOTE: This function does not kill the child process or ensure resources are cleaned up in the event of an exception from the provided function. For that, please use withCheckedProcessCleanup from the conduit-extra package.

Since 0.1.7

data ProcessExitedUnsuccessfully Source #

Indicates that a process exited with an non-success exit code.

Since 0.1.7

Constructors

ProcessExitedUnsuccessfully CreateProcess ExitCode

Instances

Instances details

Show ProcessExitedUnsuccessfully Source #
Instance details Defined in Data.Streaming.Process Methods showsPrec :: Int -> ProcessExitedUnsuccessfully -> ShowS Source # show :: ProcessExitedUnsuccessfully -> String Source # showList :: [ ProcessExitedUnsuccessfully ] -> ShowS Source #
Exception ProcessExitedUnsuccessfully Source #
Instance details Defined in Data.Streaming.Process Methods toException :: ProcessExitedUnsuccessfully -> SomeException Source # fromException :: SomeException -> Maybe ProcessExitedUnsuccessfully Source # displayException :: ProcessExitedUnsuccessfully -> String Source #

Reexport

module System.Process