HaskellWorks.Polysemy.System.Process

Documentation

data CreateProcess

Constructors

CreateProcess

Fields

• cmdspec :: CmdSpec

  Executable & arguments, or shell command. If cwd is Nothing, relative paths are resolved with respect to the current working directory. If cwd is provided, it is implementation-dependent whether relative paths are resolved with respect to cwd or the current working directory, so absolute paths should be used to ensure portability.

• 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). This implementation will call close on every fd from 3 to the maximum of open files, which can be slow for high maximum of open files.

• 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: process-1.2.0.0

• detach_console :: Bool

  Use the windows DETACHED_PROCESS flag when creating the process; does nothing on other platforms.

  Since: process-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: process-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: process-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: process-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: process-1.4.0.0

• use_process_jobs :: Bool

  On Windows systems this flag indicates that we should wait for the entire process tree to finish before unblocking. On POSIX systems this flag is ignored. See $exec-on-windows for details.

  Default: False

  Since: process-1.5.0.0

Instances

Show CreateProcess

Defined in System.Process.Common

Methods

showsPrec :: Int -> CreateProcess -> ShowS

show :: CreateProcess -> String

showList :: [CreateProcess] -> ShowS

Eq CreateProcess

Defined in System.Process.Common

Methods

(==) :: CreateProcess -> CreateProcess -> Bool

(/=) :: CreateProcess -> CreateProcess -> Bool

data CmdSpec

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: process-1.2.1.0

Defined in System.Process.Common

Methods

fromString :: String -> CmdSpec

Show CmdSpec

Defined in System.Process.Common

Methods

showsPrec :: Int -> CmdSpec -> ShowS

show :: CmdSpec -> String

showList :: [CmdSpec] -> ShowS

Eq CmdSpec

Defined in System.Process.Common

Methods

(==) :: CmdSpec -> CmdSpec -> Bool

(/=) :: CmdSpec -> CmdSpec -> Bool

data StdStream

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 Handles created by openFile).

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 Handle that writes to /dev/null.

Instances

Show StdStream

Defined in System.Process.Common

Methods

showsPrec :: Int -> StdStream -> ShowS

show :: StdStream -> String

showList :: [StdStream] -> ShowS

Eq StdStream

Defined in System.Process.Common

Methods

(==) :: StdStream -> StdStream -> Bool

(/=) :: StdStream -> StdStream -> Bool

data Handle

Haskell defines operations to read and write characters from and to files, represented by values of type Handle. Each value of this type is a handle: a record used by the Haskell run-time system to manage I/O with file system objects. A handle has at least the following properties:

• whether it manages input or output or both;
• whether it is open, closed or semi-closed;
• whether the object is seekable;
• whether buffering is disabled, or enabled on a line or block basis;
• a buffer (whose length may be zero).

Most handles will also have a current I/O position indicating where the next input or output operation will occur. A handle is readable if it manages only input or both input and output; likewise, it is writable if it manages only output or both input and output. A handle is open when first allocated. Once it is closed it can no longer be used for either input or output, though an implementation cannot re-use its storage while references remain to it. Handles are in the Show and Eq classes. The string produced by showing a handle is system dependent; it should include enough information to identify the handle for debugging. A handle is equal according to == only to itself; no attempt is made to compare the internal state of different handles for equality.

Instances

Show Handle

Since: base-4.1.0.0

Defined in GHC.IO.Handle.Types

Methods

showsPrec :: Int -> Handle -> ShowS

show :: Handle -> String

showList :: [Handle] -> ShowS

Eq Handle

Since: base-4.1.0.0

Defined in GHC.IO.Handle.Types

Methods

(==) :: Handle -> Handle -> Bool

(/=) :: Handle -> Handle -> Bool

data ProcessHandle

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.

data ExitCode

Defines the exit codes that a program can return.

Constructors

ExitSuccess

indicates successful termination;

ExitFailure Int

indicates program failure with an exit code. The exact interpretation of the code is operating-system dependent. In particular, some values may be prohibited (e.g. 0 on a POSIX-compliant system).

Instances

Exception ExitCode

Since: base-4.1.0.0

Defined in GHC.IO.Exception

Methods

toException :: ExitCode -> SomeException

fromException :: SomeException -> Maybe ExitCode

displayException :: ExitCode -> String

Generic ExitCode

Defined in GHC.IO.Exception

Associated Types

type Rep ExitCode :: Type -> Type

Methods

from :: ExitCode -> Rep ExitCode x

to :: Rep ExitCode x -> ExitCode

Read ExitCode

Defined in GHC.IO.Exception

Methods

readsPrec :: Int -> ReadS ExitCode

readList :: ReadS [ExitCode]

readPrec :: ReadPrec ExitCode

readListPrec :: ReadPrec [ExitCode]

Show ExitCode

Defined in GHC.IO.Exception

Methods

showsPrec :: Int -> ExitCode -> ShowS

show :: ExitCode -> String

showList :: [ExitCode] -> ShowS

NFData ExitCode

Since: deepseq-1.4.2.0

Defined in Control.DeepSeq

Methods

rnf :: ExitCode -> ()

Eq ExitCode

Defined in GHC.IO.Exception

Methods

(==) :: ExitCode -> ExitCode -> Bool

(/=) :: ExitCode -> ExitCode -> Bool

Ord ExitCode

Defined in GHC.IO.Exception

Methods

compare :: ExitCode -> ExitCode -> Ordering

(<) :: ExitCode -> ExitCode -> Bool

(<=) :: ExitCode -> ExitCode -> Bool

(>) :: ExitCode -> ExitCode -> Bool

(>=) :: ExitCode -> ExitCode -> Bool

max :: ExitCode -> ExitCode -> ExitCode

min :: ExitCode -> ExitCode -> ExitCode

type Rep ExitCode

Defined in GHC.IO.Exception

type Rep ExitCode = D1 ('MetaData "ExitCode" "GHC.IO.Exception" "base" 'False) (C1 ('MetaCons "ExitSuccess" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ExitFailure" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Int)))

type FD = CInt

type Pid = CPid

The platform specific type for a process identifier.

This is always an integral type. Width and signedness are platform specific.

Since: process-1.6.3.0

createProcess :: Member (Embed IO) r => Member (Error IOException) r => CreateProcess -> Sem r (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)

createProcess_ :: Member (Embed IO) r => Member (Error IOException) r => String -> CreateProcess -> Sem r (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle)

shell :: String -> CreateProcess

Construct a CreateProcess record for passing to createProcess, representing a command to be passed to the shell.

proc :: FilePath -> [String] -> CreateProcess

Construct a CreateProcess record for passing to createProcess, representing a raw command with arguments.

See RawCommand for precise semantics of the specified FilePath.

callProcess :: Member (Embed IO) r => Member (Error IOException) r => String -> [String] -> Sem r ()

callCommand :: Member (Embed IO) r => Member (Error IOException) r => String -> Sem r ()

spawnProcess :: Member (Embed IO) r => Member (Error IOException) r => String -> [String] -> Sem r ProcessHandle

spawnCommand :: Member (Embed IO) r => Member (Error IOException) r => String -> Sem r ProcessHandle

readCreateProcess :: Member (Embed IO) r => Member (Error IOException) r => CreateProcess -> String -> Sem r String

readProcess :: Member (Embed IO) r => Member (Error IOException) r => String -> [String] -> String -> Sem r String

readCreateProcessWithExitCode :: Member (Embed IO) r => Member (Error IOException) r => CreateProcess -> String -> Sem r (ExitCode, String, String)

readProcessWithExitCode :: Member (Embed IO) r => Member (Error IOException) r => String -> [String] -> String -> Sem r (ExitCode, String, String)

cleanupProcess :: Member (Embed IO) r => Member (Error IOException) r => (Maybe Handle, Maybe Handle, Maybe Handle, ProcessHandle) -> Sem r ()

getPid :: Member (Embed IO) r => Member (Error IOException) r => ProcessHandle -> Sem r (Maybe Pid)

getCurrentPid :: Member (Embed IO) r => Member (Error IOException) r => Sem r Pid

interruptProcessGroupOf :: Member (Embed IO) r => Member (Error IOException) r => ProcessHandle -> Sem r ()

createPipe :: Member (Embed IO) r => Member (Error IOException) r => Sem r (Handle, Handle)

createPipeFd :: Member (Embed IO) r => Member (Error IOException) r => Sem r (FD, FD)

runProcess :: Member (Embed IO) r => Member (Error IOException) r => FilePath -> [String] -> Maybe FilePath -> Maybe [(String, String)] -> Maybe Handle -> Maybe Handle -> Maybe Handle -> Sem r ProcessHandle

runCommand :: Member (Embed IO) r => Member (Error IOException) r => String -> Sem r ProcessHandle

runInteractiveProcess :: Member (Embed IO) r => Member (Error IOException) r => FilePath -> [String] -> Maybe FilePath -> Maybe [(String, String)] -> Sem r (Handle, Handle, Handle, ProcessHandle)

runInteractiveCommand :: Member (Embed IO) r => Member (Error IOException) r => String -> Sem r (Handle, Handle, Handle, ProcessHandle)

system :: Member (Embed IO) r => Member (Error IOException) r => String -> Sem r ExitCode

rawSystem :: Member (Embed IO) r => Member (Error IOException) r => String -> [String] -> Sem r ExitCode

waitSecondsForProcess :: Member (Embed IO) r => Member (Error GenericError) r => Member (Error IOException) r => Member (Error TimedOut) r => Member Log r => Int -> ProcessHandle -> Sem r (Maybe ExitCode)