rio-0.1.22.0: A standard library for Haskell

Safe Haskell | None
Language | Haskell2010

RIO.Process

Contents

- Process context
  - Lenses
  - Actions
- Configuring
- Spawning (run child process)
- Exec (replacing current process)
- Environment helper
- Exceptions
- Utilities
- Reexports

Description

Interacting with external processes.

This module provides a layer on top of System.Process.Typed, with the following additions:

- For efficiency, it will cache `PATH` lookups.
- For convenience, you can set the working directory and env vars overrides in a `RIO` environment instead of on the individual calls to the process.
- Built-in support for logging at the debug level.

In order to switch over to this API, the main idea is:

- Like most of the rio library, you need to create an environment value (this time `ProcessContext`), and include it in your `RIO` environment. See `mkProcessContext`.
- Instead of using the `proc` function from System.Process.Typed for creating a `ProcessConfig`, use the locally defined `proc` function, which will handle overriding environment variables, looking up paths, performing logging, etc.

Once you have your `ProcessConfig`, use the standard functions from `Typed` (reexported here for convenient) for running the `ProcessConfig`.

Since: 0.0.3.0

Synopsis

- data ProcessContext
- class HasProcessContext env where
  - processContextL :: Lens' env ProcessContext
- type EnvVars = Map Text Text
- mkProcessContext :: MonadIO m => EnvVars -> m ProcessContext
- mkDefaultProcessContext :: MonadIO m => m ProcessContext
- modifyEnvVars :: MonadIO m => ProcessContext -> (EnvVars -> EnvVars) -> m ProcessContext
- withModifyEnvVars :: (HasProcessContext env, MonadReader env m, MonadIO m) => (EnvVars -> EnvVars) -> m a -> m a
- lookupEnvFromContext :: (MonadReader env m, HasProcessContext env) => Text -> m (Maybe Text)
- withWorkingDir :: (HasProcessContext env, MonadReader env m, MonadIO m) => FilePath -> m a -> m a
- workingDirL :: HasProcessContext env => Lens' env (Maybe FilePath)
- envVarsL :: HasProcessContext env => SimpleGetter env EnvVars
- envVarsStringsL :: HasProcessContext env => SimpleGetter env [(String, String)]
- exeSearchPathL :: HasProcessContext env => SimpleGetter env [FilePath]
- resetExeCache :: (MonadIO m, MonadReader env m, HasProcessContext env) => m ()
- proc :: (HasProcessContext env, HasLogFunc env, MonadReader env m, MonadIO m, HasCallStack) => FilePath -> [String] -> (ProcessConfig () () () -> m a) -> m a
- withProcess :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a
- withProcess_ :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a
- withProcessWait :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a
- withProcessWait_ :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a
- withProcessTerm :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a
- withProcessTerm_ :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a
- exec :: (HasProcessContext env, HasLogFunc env) => String -> [String] -> RIO env b
- execSpawn :: (HasProcessContext env, HasLogFunc env) => String -> [String] -> RIO env a
- data LoggedProcessContext = LoggedProcessContext ProcessContext LogFunc
- withProcessContextNoLogging :: MonadIO m => RIO LoggedProcessContext a -> m a
- data ProcessException
  - = NoPathFound
  - | ExecutableNotFound String [FilePath]
  - | ExecutableNotFoundAt FilePath
  - | PathsInvalidInPath [FilePath]
- doesExecutableExist :: (MonadIO m, MonadReader env m, HasProcessContext env) => String -> m Bool
- findExecutable :: (MonadIO m, MonadReader env m, HasProcessContext env) => String -> m (Either ProcessException FilePath)
- exeExtensions :: (MonadIO m, MonadReader env m, HasProcessContext env) => m [String]
- augmentPath :: [FilePath] -> Maybe Text -> Either ProcessException Text
- augmentPathMap :: [FilePath] -> EnvVars -> Either ProcessException EnvVars
- augmentPathMap' :: Text -> [FilePath] -> EnvVars -> Either ProcessException EnvVars
- showProcessArgDebug :: String -> Text
- data ProcessConfig stdin stdout stderr
- data StreamSpec (streamType :: StreamType) a
- data StreamType
  - = STInput
  - | STOutput
- data Process stdin stdout stderr
- setStdin :: StreamSpec 'STInput stdin -> ProcessConfig stdin0 stdout stderr -> ProcessConfig stdin stdout stderr
- setStdout :: StreamSpec 'STOutput stdout -> ProcessConfig stdin stdout0 stderr -> ProcessConfig stdin stdout stderr
- setStderr :: StreamSpec 'STOutput stderr -> ProcessConfig stdin stdout stderr0 -> ProcessConfig stdin stdout stderr
- setCloseFds :: Bool -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- setCreateGroup :: Bool -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- setDelegateCtlc :: Bool -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- setDetachConsole :: Bool -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- setCreateNewConsole :: Bool -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- setNewSession :: Bool -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- setChildGroup :: GroupID -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- setChildUser :: UserID -> ProcessConfig stdin stdout stderr -> ProcessConfig stdin stdout stderr
- mkStreamSpec :: forall a (streamType :: StreamType). StdStream -> (ProcessConfig () () () -> Maybe Handle -> IO (a, IO ())) -> StreamSpec streamType a
- inherit :: forall (anyStreamType :: StreamType). StreamSpec anyStreamType ()
- closed :: forall (anyStreamType :: StreamType). StreamSpec anyStreamType ()
- byteStringInput :: ByteString -> StreamSpec 'STInput ()
- byteStringOutput :: StreamSpec 'STOutput (STM ByteString)
- createPipe :: forall (anyStreamType :: StreamType). StreamSpec anyStreamType Handle
- useHandleOpen :: forall (anyStreamType :: StreamType). Handle -> StreamSpec anyStreamType ()
- useHandleClose :: forall (anyStreamType :: StreamType). Handle -> StreamSpec anyStreamType ()
- startProcess :: MonadIO m => ProcessConfig stdin stdout stderr -> m (Process stdin stdout stderr)
- stopProcess :: MonadIO m => Process stdin stdout stderr -> m ()
- readProcess :: MonadIO m => ProcessConfig stdin stdoutIgnored stderrIgnored -> m (ExitCode, ByteString, ByteString)
- readProcess_ :: MonadIO m => ProcessConfig stdin stdoutIgnored stderrIgnored -> m (ByteString, ByteString)
- runProcess :: MonadIO m => ProcessConfig stdin stdout stderr -> m ExitCode
- runProcess_ :: MonadIO m => ProcessConfig stdin stdout stderr -> m ()
- readProcessStdout :: MonadIO m => ProcessConfig stdin stdoutIgnored stderr -> m (ExitCode, ByteString)
- readProcessStdout_ :: MonadIO m => ProcessConfig stdin stdoutIgnored stderr -> m ByteString
- readProcessStderr :: MonadIO m => ProcessConfig stdin stdout stderrIgnored -> m (ExitCode, ByteString)
- readProcessStderr_ :: MonadIO m => ProcessConfig stdin stdout stderrIgnored -> m ByteString
- waitExitCode :: MonadIO m => Process stdin stdout stderr -> m ExitCode
- waitExitCodeSTM :: Process stdin stdout stderr -> STM ExitCode
- getExitCode :: MonadIO m => Process stdin stdout stderr -> m (Maybe ExitCode)
- getExitCodeSTM :: Process stdin stdout stderr -> STM (Maybe ExitCode)
- checkExitCode :: MonadIO m => Process stdin stdout stderr -> m ()
- checkExitCodeSTM :: Process stdin stdout stderr -> STM ()
- getStdin :: Process stdin stdout stderr -> stdin
- getStdout :: Process stdin stdout stderr -> stdout
- getStderr :: Process stdin stdout stderr -> stderr
- data ExitCodeException = ExitCodeException {
  - eceExitCode :: ExitCode
  - eceProcessConfig :: ProcessConfig () () ()
  - eceStdout :: ByteString
  - eceStderr :: ByteString
  }
- data ByteStringOutputException = ByteStringOutputException SomeException (ProcessConfig () () ())
- unsafeProcessHandle :: Process stdin stdout stderr -> ProcessHandle

# Process context

data ProcessContext #

Context in which to run processes.

Since: 0.0.3.0

#### Instances

Instances details

HasProcessContext ProcessContext # |
Instance details Defined in RIO.Process Methods processContextL :: Lens' ProcessContext ProcessContext #

class HasProcessContext env where #

Get the `ProcessContext` from the environment.

Since: 0.0.3.0

Methods

processContextL :: Lens' env ProcessContext #

#### Instances

Instances details

HasProcessContext SimpleApp # |
Instance details Defined in RIO.Prelude.Simple Methods processContextL :: Lens' SimpleApp ProcessContext #
HasProcessContext LoggedProcessContext # |
Instance details Defined in RIO.Process Methods processContextL :: Lens' LoggedProcessContext ProcessContext #
HasProcessContext ProcessContext # |
Instance details Defined in RIO.Process Methods processContextL :: Lens' ProcessContext ProcessContext #

type EnvVars = Map Text Text #

The environment variable map

Since: 0.0.3.0

mkProcessContext :: MonadIO m => EnvVars -> m ProcessContext #

Create a new `ProcessContext` from the given environment variable map.

Since: 0.0.3.0

mkDefaultProcessContext :: MonadIO m => m ProcessContext #

Same as `mkProcessContext` but uses the system environment (from `getEnvironment`).

Since: 0.0.3.0

modifyEnvVars :: MonadIO m => ProcessContext -> (EnvVars -> EnvVars) -> m ProcessContext #

Modify the environment variables of a `ProcessContext`. This will not change the working directory.

Note that this requires `MonadIO`, as it will create a new `IORef` for the cache.

Since: 0.0.3.0

withModifyEnvVars :: (HasProcessContext env, MonadReader env m, MonadIO m) => (EnvVars -> EnvVars) -> m a -> m a #

Use `modifyEnvVars` to create a new `ProcessContext`, and then use it in the provided action.

Since: 0.0.3.0

lookupEnvFromContext :: (MonadReader env m, HasProcessContext env) => Text -> m (Maybe Text) #

Look into the `ProcessContext` and return the specified environmet variable if one is available.

Since: 0.1.14.0

withWorkingDir :: (HasProcessContext env, MonadReader env m, MonadIO m) => FilePath -> m a -> m a #

Set the working directory to be used by child processes.

Since: 0.0.3.0

## Lenses

workingDirL :: HasProcessContext env => Lens' env (Maybe FilePath) #

Override the working directory processes run in. `Nothing` means the current process's working directory.

Since: 0.0.3.0

envVarsL :: HasProcessContext env => SimpleGetter env EnvVars #

Get the environment variables. We cannot provide a `Lens` here, since updating the environment variables requires an `IO` action to allocate a new `IORef` for holding the executable path cache.

Since: 0.0.3.0

envVarsStringsL :: HasProcessContext env => SimpleGetter env [(String, String)] #

Get the `EnvVars` as an associated list of `String`s.

Useful for interacting with other libraries.

Since: 0.0.3.0

exeSearchPathL :: HasProcessContext env => SimpleGetter env [FilePath] #

Get the list of directories searched for executables (the `PATH`).

Similar to `envVarMapL`, this cannot be a full `Lens`.

Since: 0.0.3.0

## Actions

resetExeCache :: (MonadIO m, MonadReader env m, HasProcessContext env) => m () #

Reset the executable cache.

Since: 0.0.3.0

# Configuring

proc #

Arguments

:: (HasProcessContext env, HasLogFunc env, MonadReader env m, MonadIO m, HasCallStack) |
=> FilePath | command to run
-> [String] | command line arguments
-> (ProcessConfig () () () -> m a) |
-> m a |

Provide a `ProcessConfig` based on the `ProcessContext` in scope. Deals with resolving the full path, setting the child process's environment variables, setting the working directory, and wrapping the call with `withProcessTimeLog` for debugging output.

This is intended to be analogous to the `proc` function provided by the `System.Process.Typed` module, but has a different type signature to (1) allow it to perform `IO` actions for looking up paths, and (2) allow logging and timing of the running action.

Since: 0.0.3.0

# Spawning (run child process)

withProcess :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a #

Deprecated: Please consider using withProcessWait, or instead use withProcessTerm

Same as `withProcess`, but generalized to `MonadUnliftIO`.

Since: 0.0.3.0

withProcess_ :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a #

Deprecated: Please consider using withProcessWait, or instead use withProcessTerm

Same as `withProcess_`, but generalized to `MonadUnliftIO`.

Since: 0.0.3.0

withProcessWait :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a #

Same as `withProcessWait`, but generalized to `MonadUnliftIO`.

Since: 0.1.10.0

withProcessWait_ :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a #

Same as `withProcessWait_`, but generalized to `MonadUnliftIO`.

Since: 0.1.10.0

withProcessTerm :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a #

Same as `withProcessTerm`, but generalized to `MonadUnliftIO`.

Since: 0.1.10.0

withProcessTerm_ :: MonadUnliftIO m => ProcessConfig stdin stdout stderr -> (Process stdin stdout stderr -> m a) -> m a #

Same as `withProcessTerm_`, but generalized to `MonadUnliftIO`.

Since: 0.1.10.0

# Exec (replacing current process)

exec :: (HasProcessContext env, HasLogFunc env) => String -> [String] -> RIO env b #

Execute a process within the configured environment.

Execution will not return, because either:

1) On non-windows, execution is taken over by execv of the sub-process. This allows signals to be propagated (#527)

2) On windows, an `ExitCode` exception will be thrown.

Since: 0.0.3.0

execSpawn :: (HasProcessContext env, HasLogFunc env) => String -> [String] -> RIO env a #

Like `exec`, but does not use `execv` on non-windows. This way, there is a sub-process, which is helpful in some cases (https://github.com/commercialhaskell/stack/issues/1306).

This function only exits by throwing `ExitCode`.

Since: 0.0.3.0

# Environment helper

data LoggedProcessContext #

A convenience environment combining a `LogFunc` and a `ProcessContext`

Since: 0.0.3.0

Constructors

LoggedProcessContext ProcessContext LogFunc |

#### Instances

Instances details

HasLogFunc LoggedProcessContext # |
Instance details Defined in RIO.Process Methods logFuncL :: Lens' LoggedProcessContext LogFunc #
HasProcessContext LoggedProcessContext # |
Instance details Defined in RIO.Process Methods processContextL :: Lens' LoggedProcessContext ProcessContext #

withProcessContextNoLogging :: MonadIO m => RIO LoggedProcessContext a -> m a #

Run an action using a `LoggedProcessContext` with default settings and no logging.

Since: 0.0.3.0

# Exceptions

data ProcessException #

Exception type which may be generated in this module.

NOTE Other exceptions may be thrown by underlying libraries!

Since: 0.0.3.0

Constructors

NoPathFound |
ExecutableNotFound String [FilePath] |
ExecutableNotFoundAt FilePath |
PathsInvalidInPath [FilePath] |

#### Instances

Instances details

Exception ProcessException # |
Instance details Defined in RIO.Process Methods toException :: ProcessException -> SomeException # fromException :: SomeException -> Maybe ProcessException # displayException :: ProcessException -> String #
Show ProcessException # |
Instance details Defined in RIO.Process Methods showsPrec :: Int -> ProcessException -> ShowS # show :: ProcessException -> String # showList :: [ProcessException] -> ShowS #
Eq ProcessException # |
Instance details Defined in RIO.Process Methods (==) :: ProcessException -> ProcessException -> Bool # (/=) :: ProcessException -> ProcessException -> Bool #

# Utilities

doesExecutableExist #

Arguments

:: (MonadIO m, MonadReader env m, HasProcessContext env) |
=> String | Name of executable
-> m Bool |

Check if the given executable exists on the given PATH.

Since: 0.0.3.0

findExecutable #

Arguments

:: (MonadIO m, MonadReader env m, HasProcessContext env) |
=> String | Name of executable
-> m (Either ProcessException FilePath) | Full path to that executable on success

Find the complete path for the given executable name.

On POSIX systems, filenames that match but are not exectuables are excluded.

On Windows systems, the executable names tried, in turn, are the supplied name (only if it has an extension) and that name extended by each of the `exeExtensions`. Also, this function may behave differently from `findExecutable`. The latter excludes as executables filenames without a `.bat`, `.cmd`, `.com` or `.exe` extension (case-insensitive).

Since: 0.0.3.0

exeExtensions :: (MonadIO m, MonadReader env m, HasProcessContext env) => m [String] #

Get the filename extensions for executable files, including the dot (if any).

On POSIX systems, this is `[""]`.

On Windows systems, the list is determined by the value of the `PATHEXT` environment variable, if it present in the environment. If the variable is absent, this is its default value on a Windows system. This function may, therefore, behave differently from `exeExtension`, which returns only `".exe"`.

Since: 0.1.13.0

augmentPath :: [FilePath] -> Maybe Text -> Either ProcessException Text #

Augment the given value (assumed to be that of an environment variable that lists paths, such as PATH; this is not checked) with the given extra paths. Those paths are prepended (as in: they take precedence).

Since: 0.0.3.0

augmentPathMap :: [FilePath] -> EnvVars -> Either ProcessException EnvVars #

Apply `augmentPath` on the value of the PATH environment variable in the given `EnvVars`.

Since: 0.0.3.0

augmentPathMap' #

Arguments

:: Text | Environment variable. If it does not already exist in the given `EnvVars`, it will be created.
-> [FilePath] |
-> EnvVars |
-> Either ProcessException EnvVars |

Apply `augmentPath` on the value of the given environment variable in the given `EnvVars`.

Since: 0.1.22.0

showProcessArgDebug :: String -> Text #

Show a process arg including speechmarks when necessary. Just for debugging purposes, not functionally important.

Since: 0.0.3.0

# Reexports

data ProcessConfig stdin stdout stderr #

An abstract configuration for a process, which can then be launched into an actual running `Process`. Takes three type parameters, providing the types of standard input, standard output, and standard error, respectively.

There are three ways to construct a value of this type:

- With the `proc` smart constructor, which takes a command name and a list of arguments.
- With the `shell` smart constructor, which takes a shell string
- With the `IsString` instance via OverloadedStrings. If you provide it a string with no spaces (e.g., `"date"`), it will treat it as a raw command with no arguments (e.g., `proc "date" []`). If it has spaces, it will use `shell`.

In all cases, the default for all three streams is to inherit the streams from the parent process. For other settings, see the setters below for default values.

Once you have a `ProcessConfig` you can launch a process from it using the functions in the section Launch a process.

Since: typed-process-0.1.0.0

#### Instances

Instances details

(stdin ~ (), stdout ~ (), stderr ~ ()) => IsString (ProcessConfig stdin stdout stderr) |
Instance details Defined in System.Process.Typed.Internal Methods fromString :: String -> ProcessConfig stdin stdout stderr #
Show (ProcessConfig stdin stdout stderr) |
Instance details Defined in System.Process.Typed.Internal Methods showsPrec :: Int -> ProcessConfig stdin stdout stderr -> ShowS # show :: ProcessConfig stdin stdout stderr -> String # showList :: [ProcessConfig stdin stdout stderr] -> ShowS #
Display (ProcessConfig a b c) # | Since: 0.1.0.0
Instance details Defined in RIO.Prelude.Display Methods display :: ProcessConfig a b c -> Utf8Builder # textDisplay :: ProcessConfig a b c -> Text #

data StreamSpec (streamType :: StreamType) a #

A specification for how to create one of the three standard child streams, `stdin`, `stdout` and `stderr`. A `StreamSpec` can be thought of as containing

1. A type safe version of `StdStream` from System.Process. This determines whether the stream should be inherited from the parent process, piped to or from a `Handle`, etc.
2. A means of accessing the stream as a value of type `a`
3. A cleanup action which will be run on the stream once the process terminates

To create a `StreamSpec` see the section Stream specs.

Since: typed-process-0.1.0.0

#### Instances

Instances details

Functor (StreamSpec streamType) |
Instance details Defined in System.Process.Typed.Internal Methods fmap :: (a -> b) -> StreamSpec streamType a -> StreamSpec streamType b # (<$) :: a -> StreamSpec streamType b -> StreamSpec streamType a #
(streamType ~ 'STInput, res ~ ()) => IsString (StreamSpec streamType res) | This instance uses `byteStringInput` to convert a raw string into a stream of input for a child process. Since: typed-process-0.1.0.0
Instance details Defined in System.Process.Typed.Internal Methods fromString :: String -> StreamSpec streamType res #

data StreamType #

Whether a stream is an input stream or output stream. Note that this is from the perspective of the child process, so that a child's standard input stream is an `STInput`, even though the parent process will be writing to it.

Since: typed-process-0.1.0.0

Constructors

STInput |
STOutput |

data Process stdin stdout stderr #

A running process. The three type parameters provide the type of the standard input, standard output, and standard error streams.

To interact with a `Process` use the functions from the section Interact with a process.

Since: typed-process-0.1.0.0

#### Instances

Instances details

Show (Process stdin stdout stderr) |
Instance details Defined in System.Process.Typed Methods showsPrec :: Int -> Process stdin stdout stderr -> ShowS # show :: Process stdin stdout stderr -> String # showList :: [Process stdin stdout stderr] -> ShowS #

setStdin #

Arguments

:: StreamSpec 'STInput stdin |
-> ProcessConfig stdin0 stdout stderr |
-> ProcessConfig stdin stdout stderr |

Set the child's standard input stream to the given `StreamSpec`.

Default: `inherit`

Since: typed-process-0.1.0.0

setStdout #

Arguments

:: StreamSpec 'STOutput stdout |
-> ProcessConfig stdin stdout0 stderr |
-> ProcessConfig stdin stdout stderr |

Set the child's standard output stream to the given `StreamSpec`.

Default: `inherit`

Since: typed-process-0.1.0.0

setStderr #

Arguments

:: StreamSpec 'STOutput stderr |
-> ProcessConfig stdin stdout stderr0 |
-> ProcessConfig stdin stdout stderr |

Set the child's standard error stream to the given `StreamSpec`.

Default: `inherit`

Since: typed-process-0.1.0.0

setCloseFds #

Arguments

:: Bool |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Should we close all file descriptors besides stdin, stdout, and stderr? See `close_fds` for more information.

Default: False

Since: typed-process-0.1.0.0

setCreateGroup #

Arguments

:: Bool |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Should we create a new process group?

Default: False

Since: typed-process-0.1.0.0

setDelegateCtlc #

Arguments

:: Bool |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Delegate handling of Ctrl-C to the child. For more information, see `delegate_ctlc`.

Default: False

Since: typed-process-0.1.0.0

setDetachConsole #

Arguments

:: Bool |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Detach console on Windows, see `detach_console`.

Default: False

Since: typed-process-0.1.0.0

setCreateNewConsole #

Arguments

:: Bool |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Create new console on Windows, see `create_new_console`.

Default: False

Since: typed-process-0.1.0.0

setNewSession #

Arguments

:: Bool |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Set a new session with the POSIX `setsid` syscall, does nothing on non-POSIX. See `new_session`.

Default: False

Since: typed-process-0.1.0.0

setChildGroup #

Arguments

:: GroupID |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Set the child process's group ID with the POSIX `setgid` syscall, does nothing on non-POSIX. See `child_group`.

Default: False

Since: typed-process-0.1.0.0

setChildUser #

Arguments

:: UserID |
-> ProcessConfig stdin stdout stderr |
-> ProcessConfig stdin stdout stderr |

Set the child process's user ID with the POSIX `setuid` syscall, does nothing on non-POSIX. See `child_user`.

Default: False

Since: typed-process-0.1.0.0

mkStreamSpec #

Arguments

:: forall a (streamType :: StreamType). StdStream |
-> (ProcessConfig () () () -> Maybe Handle -> IO (a, IO ())) |
-> StreamSpec streamType a |

Create a new `StreamSpec` from the given `StdStream` and a helper function. This function:

- Takes as input the raw `Maybe Handle` returned by the `createProcess` function. The handle will be `Just` `Handle` if the `StdStream` argument is `CreatePipe` and `Nothing` otherwise. See `createProcess` for more details.
- Returns the actual stream value `a`, as well as a cleanup function to be run when calling `stopProcess`.

If making a `StreamSpec` with `CreatePipe`, prefer `mkPipeStreamSpec`, which encodes the invariant that a `Handle` is created.

Since: typed-process-0.1.0.0

inherit :: forall (anyStreamType :: StreamType). StreamSpec anyStreamType () #

A stream spec which simply inherits the stream of the parent process.

Since: typed-process-0.1.0.0

closed :: forall (anyStreamType :: StreamType). StreamSpec anyStreamType () #

A stream spec which will close the stream for 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. Prefer `nullStream` unless you're certain you want this behavior.

Since: typed-process-0.1.0.0

byteStringInput :: ByteString -> StreamSpec 'STInput () #

An input stream spec which sets the input to the given `ByteString`. A separate thread will be forked to write the contents to the child process.

Since: typed-process-0.1.0.0

byteStringOutput :: StreamSpec 'STOutput (STM ByteString) #

Capture the output of a process in a `ByteString`.

This function will fork a separate thread to consume all input from the process, and will only make the results available when the underlying `Handle` is closed. As this is provided as an `STM` action, you can either check if the result is available, or block until it's ready.

In the event of any exception occurring when reading from the `Handle`, the `STM` action will throw a `ByteStringOutputException`.

Since: typed-process-0.1.0.0

createPipe :: forall (anyStreamType :: StreamType). StreamSpec anyStreamType Handle #

Create a new pipe between this process and the child, and return a `Handle` to communicate with the child.

Since: typed-process-0.1.0.0

useHandleOpen :: forall (anyStreamType :: StreamType). Handle -> StreamSpec anyStreamType () #

Use the provided `Handle` for the child process, and when the process exits, do not close it. This is useful if, for example, you want to have multiple processes write to the same log file sequentially.

Since: typed-process-0.1.0.0

useHandleClose :: forall (anyStreamType :: StreamType). Handle -> StreamSpec anyStreamType () #

Use the provided `Handle` for the child process, and when the process exits, close it. If you have no reason to keep the `Handle` open, you should use this over `useHandleOpen`.

Since: typed-process-0.1.0.0

startProcess #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdout stderr |
-> m (Process stdin stdout stderr) |

Launch a process based on the given `ProcessConfig`. You should ensure that you call `stopProcess` on the result. It's usually better to use one of the functions in this module which ensures `stopProcess` is called, such as `withProcessWait`.

Since: typed-process-0.1.0.0

stopProcess :: MonadIO m => Process stdin stdout stderr -> m () #

Close a process and release any resources acquired. This will ensure `terminateProcess` is called, wait for the process to actually exit, and then close out resources allocated for the streams. In the event of any cleanup exceptions being thrown this will throw an exception.

Since: typed-process-0.1.0.0

readProcess #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdoutIgnored stderrIgnored |
-> m (ExitCode, ByteString, ByteString) |

Run a process, capture its standard output and error as a `ByteString`, wait for it to complete, and then return its exit code, output, and error.

Note that any previously used `setStdout` or `setStderr` will be overridden.

Since: typed-process-0.1.0.0

readProcess_ #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdoutIgnored stderrIgnored |
-> m (ByteString, ByteString) |

Same as `readProcess`, but instead of returning the `ExitCode`, checks it with `checkExitCode`.

Exceptions thrown by this function will include stdout and stderr.

Since: typed-process-0.1.0.0

runProcess #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdout stderr |
-> m ExitCode |

Run the given process, wait for it to exit, and returns its `ExitCode`.

Since: typed-process-0.1.0.0

runProcess_ #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdout stderr |
-> m () |

Same as `runProcess`, but instead of returning the `ExitCode`, checks it with `checkExitCode`.

Since: typed-process-0.1.0.0

readProcessStdout #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdoutIgnored stderr |
-> m (ExitCode, ByteString) |

Same as `readProcess`, but only read the stdout of the process. Original settings for stderr remain.

Since: typed-process-0.2.1.0

readProcessStdout_ #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdoutIgnored stderr |
-> m ByteString |

Same as `readProcessStdout`, but instead of returning the `ExitCode`, checks it with `checkExitCode`.

Exceptions thrown by this function will include stdout.

Since: typed-process-0.2.1.0

readProcessStderr #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdout stderrIgnored |
-> m (ExitCode, ByteString) |

Same as `readProcess`, but only read the stderr of the process. Original settings for stdout remain.

Since: typed-process-0.2.1.0

readProcessStderr_ #

Arguments

:: MonadIO m |
=> ProcessConfig stdin stdout stderrIgnored |
-> m ByteString |

Same as `readProcessStderr`, but instead of returning the `ExitCode`, checks it with `checkExitCode`.

Exceptions thrown by this function will include stderr.

Since: typed-process-0.2.1.0

waitExitCode :: MonadIO m => Process stdin stdout stderr -> m ExitCode #

Wait for the process to exit and then return its `ExitCode`.

Since: typed-process-0.1.0.0

waitExitCodeSTM :: Process stdin stdout stderr -> STM ExitCode #

Same as `waitExitCode`, but in `STM`.

Since: typed-process-0.1.0.0

getExitCode :: MonadIO m => Process stdin stdout stderr -> m (Maybe ExitCode) #

Check if a process has exited and, if so, return its `ExitCode`.

Since: typed-process-0.1.0.0

getExitCodeSTM :: Process stdin stdout stderr -> STM (Maybe ExitCode) #

Same as `getExitCode`, but in `STM`.

Since: typed-process-0.1.0.0

checkExitCode :: MonadIO m => Process stdin stdout stderr -> m () #

Wait for a process to exit, and ensure that it exited successfully. If not, throws an `ExitCodeException`.

Exceptions thrown by this function will not include stdout or stderr (This prevents unbounded memory usage from reading them into memory). However, some callers such as `readProcess_` catch the exception, add the stdout and stderr, and rethrow.

Since: typed-process-0.1.0.0

checkExitCodeSTM :: Process stdin stdout stderr -> STM () #

Same as `checkExitCode`, but in `STM`.

Since: typed-process-0.1.0.0

getStdin :: Process stdin stdout stderr -> stdin #

Get the child's standard input stream value.

Since: typed-process-0.1.0.0

getStdout :: Process stdin stdout stderr -> stdout #

Get the child's standard output stream value.

Since: typed-process-0.1.0.0

getStderr :: Process stdin stdout stderr -> stderr #

Get the child's standard error stream value.

Since: typed-process-0.1.0.0

data ExitCodeException #

Exception thrown by `checkExitCode` in the event of a non-success exit code. Note that `checkExitCode` is called by other functions as well, like `runProcess_` or `readProcess_`.

Note that several functions that throw an `ExitCodeException` intentionally do not populate `eceStdout` or `eceStderr`. This prevents unbounded memory usage for large stdout and stderrs.

Since: typed-process-0.1.0.0

Constructors

ExitCodeException |
Fields eceExitCode :: ExitCode eceProcessConfig :: ProcessConfig () () () eceStdout :: ByteString eceStderr :: ByteString

#### Instances

Instances details

Exception ExitCodeException |
Instance details Defined in System.Process.Typed.Internal Methods toException :: ExitCodeException -> SomeException # fromException :: SomeException -> Maybe ExitCodeException # displayException :: ExitCodeException -> String #
Show ExitCodeException |
Instance details Defined in System.Process.Typed.Internal Methods showsPrec :: Int -> ExitCodeException -> ShowS # show :: ExitCodeException -> String # showList :: [ExitCodeException] -> ShowS #

data ByteStringOutputException #

Wrapper for when an exception is thrown when reading from a child process, used by `byteStringOutput`.

Since: typed-process-0.1.0.0

Constructors

ByteStringOutputException SomeException (ProcessConfig () () ()) |

#### Instances

Instances details

Exception ByteStringOutputException |
Instance details Defined in System.Process.Typed.Internal Methods toException :: ByteStringOutputException -> SomeException # fromException :: SomeException -> Maybe ByteStringOutputException # displayException :: ByteStringOutputException -> String #
Show ByteStringOutputException |
Instance details Defined in System.Process.Typed.Internal Methods showsPrec :: Int -> ByteStringOutputException -> ShowS # show :: ByteStringOutputException -> String # showList :: [ByteStringOutputException] -> ShowS #

unsafeProcessHandle :: Process stdin stdout stderr -> ProcessHandle #

Take `ProcessHandle` out of the `Process`. This method is needed in cases one need to use low level functions from the `process` package. Use cases for this method are:

1. Send a special signal to the process.
2. Terminate the process group instead of terminating single process.
3. Use platform specific API on the underlying process.

This method is considered unsafe because the actions it performs on the underlying process may overlap with the functionality that `typed-process` provides. For example the user should not call `waitForProcess` on the process handle as either `waitForProcess` or `stopProcess` will lock. Additionally, even if process was terminated by the `terminateProcess` or by sending signal, `stopProcess` should be called either way in order to cleanup resources allocated by the `typed-process`.

Since: typed-process-0.1.1