Data.Conduit.Process

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

Some utilities in this module require the threaded runtime because they use waitForProcess internally.

Note that this is a very thin layer around the Data.Streaming.Process module. In particular, it:

• Provides orphan instances for conduit
• Provides some useful helper functions

Functions

sourceCmdWithConsumer

Arguments

:: MonadIO m

=> String

command

-> ConduitT ByteString Void m a

stdout

-> m (ExitCode, a)

Like sourceProcessWithConsumer but providing the command to be run as a String.

Requires the threaded runtime.

Since 1.1.2

sourceProcessWithConsumer

Arguments

:: MonadIO m

=> CreateProcess

-> ConduitT ByteString Void m a

stdout

-> m (ExitCode, a)

Given a CreateProcess, run the process, with its output being used as a Source to feed the provided Consumer. Once the process has completed, return a tuple of the ExitCode from the process and the output collected from the Consumer.

Note that, if an exception is raised by the consumer, the process is not terminated. This behavior is different from sourceProcessWithStreams due to historical reasons.

Requires the threaded runtime.

Since 1.1.2

sourceCmdWithStreams

Arguments

:: MonadUnliftIO m

=> String

command

-> ConduitT () ByteString m ()

stdin

-> ConduitT ByteString Void m a

stdout

-> ConduitT ByteString Void m b

stderr

-> m (ExitCode, a, b)

Like sourceProcessWithStreams but providing the command to be run as a String.

Requires the threaded runtime.

Since: 1.1.12

sourceProcessWithStreams

Arguments

:: MonadUnliftIO m

=> CreateProcess

-> ConduitT () ByteString m ()

stdin

-> ConduitT ByteString Void m a

stdout

-> ConduitT ByteString Void m b

stderr

-> m (ExitCode, a, b)

Given a CreateProcess, run the process and feed the provided Producer to the stdin Sink of the process. Use the process outputs (stdout, stderr) as Sources and feed it to the provided Consumers. Once the process has completed, return a tuple of the ExitCode from the process and the results collected from the Consumers.

If an exception is raised by any of the streams, the process is terminated.

IO is required because the streams are run concurrently using the async package

Requires the threaded runtime.

Since: 1.1.12

withCheckedProcessCleanup :: (InputSource stdin, OutputSink stderr, OutputSink stdout, MonadUnliftIO m) => CreateProcess -> (stdin -> stdout -> stderr -> m b) -> m b

Same as withCheckedProcess, but kills the child process in the case of an exception being thrown by the provided callback function.

Requires the threaded runtime.

Since: 1.1.11

InputSource types

newtype FlushInput o m r

Wrapper for input source which accepts Flushes. Note that the pipe will not automatically close then processing completes.

Since: 1.3.2

Constructors

FlushInput (ConduitM (Flush ByteString) o m r)

Instances

(MonadIO m, MonadIO n, r ~ (), r' ~ ()) => InputSource (FlushInput o m r, n r')

Defined in Data.Conduit.Process

Methods

isStdStream :: (Maybe Handle -> IO (FlushInput o m r, n r'), Maybe StdStream)

(MonadIO m, r ~ ()) => InputSource (FlushInput o m r)

Defined in Data.Conduit.Process

Methods

isStdStream :: (Maybe Handle -> IO (FlushInput o m r), Maybe StdStream)

newtype BuilderInput o m r

Wrapper for input source which accepts Builders. You can pass flush to flush the input. Note that the pipe will not automatically close when the processing completes.

Since: 1.3.2

Constructors

BuilderInput (ConduitM Builder o m r)

Instances

(MonadIO m, MonadIO n, r ~ (), r' ~ ()) => InputSource (BuilderInput o m r, n r')

Defined in Data.Conduit.Process

Methods

isStdStream :: (Maybe Handle -> IO (BuilderInput o m r, n r'), Maybe StdStream)

(MonadIO m, r ~ ()) => InputSource (BuilderInput o m r)

Defined in Data.Conduit.Process

Methods

isStdStream :: (Maybe Handle -> IO (BuilderInput o m r), Maybe StdStream)

Reexport

module Data.Streaming.Process

Orphan instances

(r ~ (), r' ~ (), MonadIO m, MonadIO n, i ~ ByteString) => InputSource (ConduitM i o m r, n r')

Methods

isStdStream :: (Maybe Handle -> IO (ConduitM i o m r, n r'), Maybe StdStream)

(r ~ (), r' ~ (), MonadIO m, MonadIO n, o ~ ByteString) => OutputSink (ConduitM i o m r, n r')

Methods

osStdStream :: (Maybe Handle -> IO (ConduitM i o m r, n r'), Maybe StdStream)

(r ~ (), MonadIO m, i ~ ByteString) => InputSource (ConduitM i o m r)

Methods

isStdStream :: (Maybe Handle -> IO (ConduitM i o m r), Maybe StdStream)

(r ~ (), MonadIO m, o ~ ByteString) => OutputSink (ConduitM i o m r)

Methods

osStdStream :: (Maybe Handle -> IO (ConduitM i o m r), Maybe StdStream)