Shelly

shelly-1.12.1: shell-like (systems) programming in Haskell

Safe Haskell | None
Language | Haskell2010

Shelly

Contents

- Entering Sh
- Running external commands
- Running commands Using handles
- Handle manipulation
- Modifying and querying environment
- Environment directory
- Printing
- Querying filesystem
- Filename helpers
- Manipulating filesystem
- reading/writing Files
- exiting the program
- Exceptions
- convert between Text and FilePath
- Utility Functions
- Re-exported for your convenience
- internal functions for writing extensions
- find functions

Description

A module for shell-like programming in Haskell. Shelly's focus is entirely on ease of use for those coming from shell scripting. However, it also tries to use modern libraries and techniques to keep things efficient.

The functionality provided by this module is (unlike standard Haskell filesystem functionality) thread-safe: each Sh maintains its own environment and its own working directory.

Recommended usage includes putting the following at the top of your program, otherwise you will likely need either type annotations or type conversions

    {-# LANGUAGE OverloadedStrings #-}
    {-# LANGUAGE ExtendedDefaultRules #-}
    {-# OPTIONS_GHC -fno-warn-type-defaults #-}
    import Shelly
    import qualified Data.Text as T
    default (T.Text)

Synopsis

- data Sh a
- type ShIO a = Sh a
- shelly :: MonadIO m => Sh a -> m a
- shellyNoDir :: MonadIO m => Sh a -> m a
- shellyFailDir :: MonadIO m => Sh a -> m a
- asyncSh :: Sh a -> Sh (Async a)
- sub :: Sh a -> Sh a
- silently :: Sh a -> Sh a
- verbosely :: Sh a -> Sh a
- escaping :: Bool -> Sh a -> Sh a
- print_stdout :: Bool -> Sh a -> Sh a
- print_stderr :: Bool -> Sh a -> Sh a
- print_commands :: Bool -> Sh a -> Sh a
- print_commands_with :: (Text -> IO ()) -> Sh a -> Sh a
- onCommandHandles :: StdInit -> Sh a -> Sh a
- tracing :: Bool -> Sh a -> Sh a
- errExit :: Bool -> Sh a -> Sh a
- log_stdout_with :: (Text -> IO ()) -> Sh a -> Sh a
- log_stderr_with :: (Text -> IO ()) -> Sh a -> Sh a
- run :: FilePath -> [Text] -> Sh Text
- run_ :: FilePath -> [Text] -> Sh ()
- runFoldLines :: a -> FoldCallback a -> FilePath -> [Text] -> Sh a
- cmd :: ShellCmd result => FilePath -> result
- type FoldCallback a = a -> Text -> a
- bash :: FilePath -> [Text] -> Sh Text
- bash_ :: FilePath -> [Text] -> Sh ()
- bashPipeFail :: (FilePath -> [Text] -> Sh a) -> FilePath -> [Text] -> Sh a
- (-|-) :: Sh Text -> Sh b -> Sh b
- lastStderr :: Sh Text
- setStdin :: Text -> Sh ()
- lastExitCode :: Sh Int
- command :: FilePath -> [Text] -> [Text] -> Sh Text
- command_ :: FilePath -> [Text] -> [Text] -> Sh ()
- command1 :: FilePath -> [Text] -> Text -> [Text] -> Sh Text
- command1_ :: FilePath -> [Text] -> Text -> [Text] -> Sh ()
- sshPairs :: Text -> [(FilePath, [Text])] -> Sh Text
- sshPairsPar :: Text -> [(FilePath, [Text])] -> Sh Text
- sshPairs_ :: Text -> [(FilePath, [Text])] -> Sh ()
- sshPairsPar_ :: Text -> [(FilePath, [Text])] -> Sh ()
- sshPairsWithOptions :: Text -> [Text] -> [(FilePath, [Text])] -> Sh Text
- sshCommandText :: [(FilePath, [Text])] -> SshMode -> Text
- data SshMode
  - = ParSsh
  - | SeqSsh
- class ShellCmd t where
  - cmdAll :: FilePath -> [Text] -> t
- class CmdArg a where
  - toTextArgs :: a -> [Text]
- runHandle :: FilePath -> [Text] -> (Handle -> Sh a) -> Sh a
- runHandles :: FilePath -> [Text] -> [StdHandle] -> (Handle -> Handle -> Handle -> Sh a) -> Sh a
- transferLinesAndCombine :: Handle -> (Text -> IO ()) -> IO Text
- transferFoldHandleLines :: a -> FoldCallback a -> Handle -> (Text -> IO ()) -> IO a
- data StdHandle
  - = InHandle StdStream
  - | OutHandle StdStream
  - | ErrorHandle StdStream
- data StdStream
  - = Inherit
  - | UseHandle Handle
  - | CreatePipe
  - | NoStream
- type HandleInitializer = Handle -> IO ()
- data StdInit = StdInit {
  - inInit :: HandleInitializer
  - outInit :: HandleInitializer
  - errInit :: HandleInitializer
  }
- initOutputHandles :: HandleInitializer -> StdInit
- initAllHandles :: HandleInitializer -> StdInit
- setenv :: Text -> Text -> Sh ()
- get_env :: Text -> Sh (Maybe Text)
- get_env_text :: Text -> Sh Text
- getenv :: Text -> Sh Text
- get_env_def :: Text -> Text -> Sh Text
- get_env_all :: Sh [(String, String)]
- get_environment :: Sh [(String, String)]
- appendToPath :: FilePath -> Sh ()
- prependToPath :: FilePath -> Sh ()
- cd :: FilePath -> Sh ()
- chdir :: FilePath -> Sh a -> Sh a
- chdir_p :: FilePath -> Sh a -> Sh a
- pwd :: Sh FilePath
- echo :: Text -> Sh ()
- echo_n :: Text -> Sh ()
- echo_err :: Text -> Sh ()
- echo_n_err :: Text -> Sh ()
- echoWith :: (Text -> IO ()) -> Text -> Sh ()
- inspect :: Show s => s -> Sh ()
- inspect_err :: Show s => s -> Sh ()
- tag :: Sh a -> Text -> Sh a
- trace :: Text -> Sh ()
- show_command :: FilePath -> [Text] -> Text
- ls :: FilePath -> Sh [FilePath]
- lsT :: FilePath -> Sh [Text]
- test_e :: FilePath -> Sh Bool
- test_f :: FilePath -> Sh Bool
- test_d :: FilePath -> Sh Bool
- test_s :: FilePath -> Sh Bool
- test_px :: FilePath -> Sh Bool
- which :: FilePath -> Sh (Maybe FilePath)
- absPath :: FilePath -> Sh FilePath
- (</>) :: (ToFilePath filepath1, ToFilePath filepath2) => filepath1 -> filepath2 -> FilePath
- (<.>) :: ToFilePath filepath => filepath -> Text -> FilePath
- canonic :: FilePath -> Sh FilePath
- canonicalize :: FilePath -> Sh FilePath
- relPath :: FilePath -> Sh FilePath
- relativeTo :: FilePath -> FilePath -> Sh FilePath
- path :: FilePath -> Sh FilePath
- hasExt :: Text -> FilePath -> Bool
- mv :: FilePath -> FilePath -> Sh ()
- rm :: FilePath -> Sh ()
- rm_f :: FilePath -> Sh ()
- rm_rf :: FilePath -> Sh ()
- cp :: FilePath -> FilePath -> Sh ()
- cp_r :: FilePath -> FilePath -> Sh ()
- mkdir :: FilePath -> Sh ()
- mkdir_p :: FilePath -> Sh ()
- mkdirTree :: Tree FilePath -> Sh ()
- readfile :: FilePath -> Sh Text
- readBinary :: FilePath -> Sh ByteString
- writefile :: FilePath -> Text -> Sh ()
- writeBinary :: FilePath -> ByteString -> Sh ()
- appendfile :: FilePath -> Text -> Sh ()
- touchfile :: FilePath -> Sh ()
- withTmpDir :: (FilePath -> Sh a) -> Sh a
- exit :: Int -> Sh a
- errorExit :: Text -> Sh a
- quietExit :: Int -> Sh a
- terror :: Text -> Sh a
- bracket_sh :: Sh a -> (a -> Sh b) -> (a -> Sh c) -> Sh c
- catchany :: IO a -> (SomeException -> IO a) -> IO a
- catch_sh :: Exception e => Sh a -> (e -> Sh a) -> Sh a
- handle_sh :: Exception e => (e -> Sh a) -> Sh a -> Sh a
- handleany_sh :: (SomeException -> Sh a) -> Sh a -> Sh a
- finally_sh :: Sh a -> Sh b -> Sh a
- data ShellyHandler a = Exception e => ShellyHandler (e -> Sh a)
- catches_sh :: Sh a -> [ShellyHandler a] -> Sh a
- catchany_sh :: Sh a -> (SomeException -> Sh a) -> Sh a
- data ReThrownException e = ReThrownException e String
- data RunFailed = RunFailed FilePath [Text] Int Text
- toTextIgnore :: FilePath -> Text
- toTextWarn :: FilePath -> Sh Text
- fromText :: Text -> FilePath
- whenM :: Monad m => m Bool -> m () -> m ()
- unlessM :: Monad m => m Bool -> m () -> m ()
- time :: Sh a -> Sh (Double, a)
- sleep :: Int -> Sh ()
- liftIO :: MonadIO m => IO a -> m a
- when :: Applicative f => Bool -> f () -> f ()
- unless :: Applicative f => Bool -> f () -> f ()
- type FilePath = String
- (<$>) :: Functor f => (a -> b) -> f a -> f b
- get :: Sh State
- put :: State -> Sh ()
- find :: FilePath -> Sh [FilePath]
- findWhen :: (FilePath -> Sh Bool) -> FilePath -> Sh [FilePath]
- findFold :: (a -> FilePath -> Sh a) -> a -> FilePath -> Sh a
- findDirFilter :: (FilePath -> Sh Bool) -> FilePath -> Sh [FilePath]
- findDirFilterWhen :: (FilePath -> Sh Bool) -> (FilePath -> Sh Bool) -> FilePath -> Sh [FilePath]
- findFoldDirFilter :: (a -> FilePath -> Sh a) -> a -> (FilePath -> Sh Bool) -> FilePath -> Sh a
- followSymlink :: Bool -> Sh a -> Sh a

# Entering Sh

data Sh a #

#### Instances

Instances details

MonadIO Sh # |
Instance details Defined in Shelly.Base Methods liftIO :: IO a -> Sh a #
MonadCatch Sh # |
Instance details Defined in Shelly.Base Methods catch :: (HasCallStack, Exception e) => Sh a -> (e -> Sh a) -> Sh a #
MonadMask Sh # |
Instance details Defined in Shelly.Base Methods mask :: HasCallStack => ((forall a. Sh a -> Sh a) -> Sh b) -> Sh b # uninterruptibleMask :: HasCallStack => ((forall a. Sh a -> Sh a) -> Sh b) -> Sh b # generalBracket :: HasCallStack => Sh a -> (a -> ExitCase b -> Sh c) -> (a -> Sh b) -> Sh (b, c) #
MonadThrow Sh # |
Instance details Defined in Shelly.Base Methods throwM :: (HasCallStack, Exception e) => e -> Sh a #
Applicative Sh # |
Instance details Defined in Shelly.Base Methods pure :: a -> Sh a # (<*>) :: Sh (a -> b) -> Sh a -> Sh b # liftA2 :: (a -> b -> c) -> Sh a -> Sh b -> Sh c # (*>) :: Sh a -> Sh b -> Sh b # (<*) :: Sh a -> Sh b -> Sh a #
Functor Sh # |
Instance details Defined in Shelly.Base Methods fmap :: (a -> b) -> Sh a -> Sh b # (<$) :: a -> Sh b -> Sh a #
Monad Sh # |
Instance details Defined in Shelly.Base Methods (>>=) :: Sh a -> (a -> Sh b) -> Sh b # (>>) :: Sh a -> Sh b -> Sh b # return :: a -> Sh a #
MonadFail Sh # |
Instance details Defined in Shelly.Base Methods fail :: String -> Sh a #
MonadSh Sh # |
Instance details Defined in Shelly.Lifted Methods liftSh :: Sh a -> Sh a #
MonadShControl Sh # |
Instance details Defined in Shelly.Lifted Associated Types
newtype ShM Sh a |
Instance details Defined in Shelly.Lifted newtype ShM Sh a = ShSh a
Methods liftShWith :: ((forall x. Sh x -> Sh (ShM Sh x)) -> Sh a) -> Sh a # restoreSh :: ShM Sh a -> Sh a #
MonadBaseControl IO Sh # |
Instance details Defined in Shelly.Base Associated Types
type StM Sh a |
Instance details Defined in Shelly.Base type StM Sh a
Methods liftBaseWith :: (RunInBase Sh IO -> IO a) -> Sh a # restoreM :: StM Sh a -> Sh a #
MonadBase IO Sh # |
Instance details Defined in Shelly.Base Methods liftBase :: IO α -> Sh α #
ShellCmd (Sh Text) # |
Instance details Defined in Shelly Methods cmdAll :: FilePath -> [Text] -> Sh Text #
s ~ () => ShellCmd (Sh s) # |
Instance details Defined in Shelly Methods cmdAll :: FilePath -> [Text] -> Sh s #
newtype ShM Sh a # |
Instance details Defined in Shelly.Lifted newtype ShM Sh a = ShSh a
type StM Sh a # |
Instance details Defined in Shelly.Base type StM Sh a

type ShIO a = Sh a #

Deprecated: Use Sh instead of ShIO

ShIO is Deprecated in favor of `Sh`, which is easier to type.

shelly :: MonadIO m => Sh a -> m a #

Enter a Sh from (Monad)IO. The environment and working directories are inherited from the current process-wide values. Any subsequent changes in processwide working directory or environment are not reflected in the running Sh.

shellyNoDir :: MonadIO m => Sh a -> m a #

Deprecated: Just use shelly. The default settings have changed

Deprecated now, just use `shelly`, whose default has been changed. Using this entry point does not create a `.shelly` directory in the case of failure. Instead it logs directly into the standard error stream (`stderr`).

shellyFailDir :: MonadIO m => Sh a -> m a #

Using this entry point creates a `.shelly` directory in the case of failure where errors are recorded.

asyncSh :: Sh a -> Sh (Async a) #

Spawn an asynchronous action with a copy of the current state.

sub :: Sh a -> Sh a #

Enter a sub-Sh that inherits the environment The original state will be restored when the sub-Sh completes. Exceptions are propagated normally.

silently :: Sh a -> Sh a #

Create a sub-Sh in which external command outputs are not echoed and commands are not printed. See `sub`.

verbosely :: Sh a -> Sh a #

Create a sub-Sh in which external command outputs are echoed and Executed commands are printed See `sub`.

escaping :: Bool -> Sh a -> Sh a #

Create a sub-Sh with shell character escaping on or off. Defaults to `True`.

Setting to `False` allows for shell wildcard such as * to be expanded by the shell along with any other special shell characters. As a side-effect, setting to `False` causes changes to `PATH` to be ignored: see the `run` documentation.

print_stdout :: Bool -> Sh a -> Sh a #

Create a sub-Sh with stdout printing on or off Defaults to True.

print_stderr :: Bool -> Sh a -> Sh a #

Create a sub-Sh with stderr printing on or off Defaults to True.

print_commands :: Bool -> Sh a -> Sh a #

Create a sub-Sh with command echoing on or off Defaults to False, set to True by `verbosely`

print_commands_with :: (Text -> IO ()) -> Sh a -> Sh a #

Create a sub-Sh in which commands are sent to the user-defined function.

Since: 1.12.1

onCommandHandles :: StdInit -> Sh a -> Sh a #

When running an external command, apply the given initializers to the specified handles for that command. This can for example be used to change the encoding of the handles or set them into binary mode.

tracing :: Bool -> Sh a -> Sh a #

Create a sub-Sh where commands are not traced Defaults to `True`. You should only set to `False` temporarily for very specific reasons.

errExit :: Bool -> Sh a -> Sh a #

named after bash -e errexit. Defaults to `True`. When `True`, throw an exception on a non-zero exit code. When `False`, ignore a non-zero exit code. Not recommended to set to `False` unless you are specifically checking the error code with `lastExitCode`.

log_stdout_with :: (Text -> IO ()) -> Sh a -> Sh a #

Create a sub-Sh in which stdout is sent to the user-defined logger. When running with `silently` the given log will not be called for any output. Likewise the log will also not be called for output from `run_` and `bash_` commands.

log_stderr_with :: (Text -> IO ()) -> Sh a -> Sh a #

Create a sub-Sh in which stderr is sent to the user-defined logger. When running with `silently` the given log will not be called for any output. However, unlike `log_stdout_with` the log will be called for output from `run_` and `bash_` commands.

# Running external commands

run :: FilePath -> [Text] -> Sh Text #

Execute an external command. Takes the command name and arguments.

You may prefer using `cmd` instead, which is a variadic argument version of this function.

`stdout` and `stderr` are collected. The `stdout` is returned as a result of `run`, and complete stderr output is available after the fact using `lastStderr`. If the output does not end with a newline, it is automatically added.

All of the stdout output will be loaded into memory. You can avoid this if you don't need stdout by using `run_`, If you want to avoid the memory and need to process the output then use `runFoldLines` or `runHandle` or `runHandles`.

By default shell characters are escaped and the command name is a name of a program that can be found via `PATH`. Shelly will look through the `PATH` itself to find the command.

When `escaping` is set to `False`, shell characters are allowed. Since there is no longer a guarantee that a single program name is given, Shelly cannot look in the `PATH` for it. a `PATH` modified by setenv is not taken into account when finding the exe name. Instead the original Haskell program `PATH` is used. On a Posix system the `env` command can be used to make the `setenv` PATH used when `escaping` is set to False. `env echo hello` instead of `echo hello`.

run_ :: FilePath -> [Text] -> Sh () #

The same as `run`, but return `()` instead of the stdout content. The stdout will be read and discarded line-by-line.

runFoldLines :: a -> FoldCallback a -> FilePath -> [Text] -> Sh a #

Used by `run`. Folds over `stdout` line-by-line as it is read to avoid keeping it in memory. `stderr` is still being placed in memory under the assumption it is always relatively small.

cmd :: ShellCmd result => FilePath -> result #

Variadic argument version of `run`. Please see the documenation for `run`.

The syntax is more convenient, but more importantly it also allows the use of a `FilePath` as a command argument. So an argument can be a `Text` or a `FilePath` without manual conversions. a `FilePath` is automatically converted to `Text` with `toTextIgnore`.

Convenient usage of `cmd` requires the following:

    {-# LANGUAGE OverloadedStrings #-}
    {-# LANGUAGE ExtendedDefaultRules #-}
    {-# OPTIONS_GHC -fno-warn-type-defaults #-}
    import Shelly
    import qualified Data.Text as T
    default (T.Text)

type FoldCallback a = a -> Text -> a #

bash :: FilePath -> [Text] -> Sh Text #

Like `run`, but it invokes the user-requested program with `bash`.

bash_ :: FilePath -> [Text] -> Sh () #

bashPipeFail :: (FilePath -> [Text] -> Sh a) -> FilePath -> [Text] -> Sh a #

Use this with `bash` to set `pipefail`.

    bashPipeFail $ bash "echo foo | echo"

(-|-) :: Sh Text -> Sh b -> Sh b #

Pipe operator. Set the `stdout` the first command as the `stdin` of the second. This does not create a shell-level pipe, but hopefully it will in the future. To create a shell level pipe you can set `escaping False` and use a pipe `|` character in a command.

lastStderr :: Sh Text #

The output of last external command. See `run`.

setStdin :: Text -> Sh () #

Set the `stdin` to be used and cleared by the next `run`.

lastExitCode :: Sh Int #

The exit code from the last command. Unless you set `errExit` to False you won't get a chance to use this: a non-zero exit code will throw an exception.

command :: FilePath -> [Text] -> [Text] -> Sh Text #

Bind some arguments to `run` for re-use. Example:

    monit = command "monit" ["-c", "monitrc"]
    monit ["stop", "program"]

command_ :: FilePath -> [Text] -> [Text] -> Sh () #

Bind some arguments to `run_` for re-use. Example:

    monit_ = command_ "monit" ["-c", "monitrc"]
    monit_ ["stop", "program"]

command1 :: FilePath -> [Text] -> Text -> [Text] -> Sh Text #

Bind some arguments to `run` for re-use, and require 1 argument. Example:

    git = command1 "git" []
    git "pull" ["origin", "master"]

command1_ :: FilePath -> [Text] -> Text -> [Text] -> Sh () #

Bind some arguments to `run_` for re-use, and require 1 argument. Example:

    git_ = command1_ "git" []
    git "pull" ["origin", "master"]

sshPairs :: Text -> [(FilePath, [Text])] -> Sh Text #

Run commands over SSH. An `ssh` executable is expected in your path. Commands are in the same form as `run`, but given as pairs

    sshPairs "server-name" [("cd", "dir"), ("rm",["-r","dir2"])]

This interface is crude, but it works for now.

Please note this sets `escaping` to False, and the remote commands are quoted with single quotes, in a way such that the remote commands will see the literal values you passed, this means that no variable expansion and alike will done on either the local shell or the remote shell, and that if there are a single or double quotes in your arguments, they need not to be quoted manually.

Internally the list of commands are combined with the string `&&` before given to `ssh`.

sshPairsPar :: Text -> [(FilePath, [Text])] -> Sh Text #

Same as `sshPairs`, but combines commands with the string `&`, so they will be started in parallel.

sshPairs_ :: Text -> [(FilePath, [Text])] -> Sh () #

Same as `sshPairs`, but returns `()`.

sshPairsPar_ :: Text -> [(FilePath, [Text])] -> Sh () #

Same as `sshPairsPar`, but returns `()`.

sshPairsWithOptions #

Arguments

:: Text | Server name.
-> [Text] | Arguments to `ssh` (e.g. `["-p","22"]`).
-> [(FilePath, [Text])] | Pairs of commands to run on the remote.
-> Sh Text | Returns the standard output.

Like `sshPairs`, but allows for arguments to the call to `ssh`.

sshCommandText :: [(FilePath, [Text])] -> SshMode -> Text #

data SshMode #

Constructors

ParSsh |
SeqSsh |

class ShellCmd t where #

For the variadic function `cmd`.

Partially applied variadic functions require type signatures.

Methods

cmdAll :: FilePath -> [Text] -> t #

#### Instances

Instances details

ShellCmd (Sh Text) # |
Instance details Defined in Shelly Methods cmdAll :: FilePath -> [Text] -> Sh Text #
s ~ () => ShellCmd (Sh s) # |
Instance details Defined in Shelly Methods cmdAll :: FilePath -> [Text] -> Sh s #
MonadSh m => ShellCmd (m Text) # |
Instance details Defined in Shelly.Lifted Methods cmdAll :: FilePath -> [Text] -> m Text #
MonadSh m => ShellCmd (m ()) # |
Instance details Defined in Shelly.Lifted Methods cmdAll :: FilePath -> [Text] -> m () #
(MonadSh m, s ~ Text, Show s) => ShellCmd (m s) # |
Instance details Defined in Shelly.Lifted Methods cmdAll :: FilePath -> [Text] -> m s #
(CmdArg arg, ShellCmd result) => ShellCmd (arg -> result) # |
Instance details Defined in Shelly Methods cmdAll :: FilePath -> [Text] -> arg -> result #

class CmdArg a where #

Argument converter for the variadic argument version of `run` called `cmd`. Useful for a type signature of a function that uses `cmd`.

Methods

toTextArgs :: a -> [Text] #

Since: 1.12.0

#### Instances

Instances details

CmdArg Text # |
Instance details Defined in Shelly Methods toTextArgs :: Text -> [Text] #
CmdArg String # |
Instance details Defined in Shelly Methods toTextArgs :: String -> [Text] #
CmdArg a => CmdArg [a] # |
Instance details Defined in Shelly Methods toTextArgs :: [a] -> [Text] #

# Running commands Using handles

runHandle #

Arguments

:: FilePath | Command.
-> [Text] | Arguments.
-> (Handle -> Sh a) | `stdout` handle.
-> Sh a |

Similar to `run` but gives the raw stdout handle in a callback. If you want even more control, use `runHandles`.

runHandles #

Arguments

:: FilePath | Command.
-> [Text] | Arguments.
-> [StdHandle] | Optionally connect process i/o handles to existing handles.
-> (Handle -> Handle -> Handle -> Sh a) | `stdin`, `stdout` and `stderr`.
-> Sh a |

Similar to `run` but gives direct access to all input and output handles.

Be careful when using the optional input handles. If you specify `Inherit` for a handle then attempting to access the handle in your callback is an error.

transferLinesAndCombine :: Handle -> (Text -> IO ()) -> IO Text #

Transfer from one handle to another For example, send contents of a process output to stdout. Does not close the write handle.

Also, return the complete contents being streamed line by line.

transferFoldHandleLines :: a -> FoldCallback a -> Handle -> (Text -> IO ()) -> IO a #

Transfer from one handle to another For example, send contents of a process output to stdout. Does not close the write handle.

Also, fold over the contents being streamed line by line.

data StdHandle #

Constructors

InHandle StdStream |
OutHandle StdStream |
ErrorHandle StdStream |

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 `Handle`s 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

Instances details

Show StdStream |
Instance details Defined in System.Process.Common Methods showsPrec :: Int -> StdStream -> ShowS # show :: StdStream -> String # showList :: [StdStream] -> ShowS #
Eq StdStream |
Instance details Defined in System.Process.Common Methods (==) :: StdStream -> StdStream -> Bool # (/=) :: StdStream -> StdStream -> Bool #

# Handle manipulation

type HandleInitializer = Handle -> IO () #

Initialize a handle before using it.

data StdInit #

A collection of initializers for the three standard process handles.

Constructors

StdInit |
Fields inInit :: HandleInitializer outInit :: HandleInitializer errInit :: HandleInitializer

initOutputHandles :: HandleInitializer -> StdInit #

Apply a single initializer to the two output process handles (stdout and stderr).

initAllHandles :: HandleInitializer -> StdInit #

Apply a single initializer to all three standard process handles (stdin, stdout and stderr).

# Modifying and querying environment

setenv :: Text -> Text -> Sh () #

Set an environment variable. The environment is maintained in Sh internally, and is passed to any external commands to be executed.

get_env :: Text -> Sh (Maybe Text) #

Fetch the current value of an environment variable. If non-existant or empty text, will be `Nothing`.

get_env_text :: Text -> Sh Text #

Fetch the current value of an environment variable. Both empty and non-existent variables give empty string as a result.

getenv :: Text -> Sh Text #

Deprecated: use get_env or get_env_text

get_env_def :: Text -> Text -> Sh Text #

Deprecated: use fromMaybe DEFAULT get_env

Fetch the current value of an environment variable. Both empty and non-existent variables give the default `Text` value as a result.

get_env_all :: Sh [(String, String)] #

Get the full environment.

get_environment :: Sh [(String, String)] #

Deprecated: use get_env_all

appendToPath :: FilePath -> Sh () #

Add the filepath onto the PATH env variable.

prependToPath :: FilePath -> Sh () #

Prepend the filepath to the PATH env variable. Similar to `appendToPath` but gives high priority to the filepath instead of low priority.

# Environment directory

cd :: FilePath -> Sh () #

Change current working directory of `Sh`. This does not change the working directory of the process we are running it. Instead, `Sh` keeps track of its own working directory and builds absolute paths internally instead of passing down relative paths.

chdir :: FilePath -> Sh a -> Sh a #

`cd`, execute a `Sh` action in the new directory and then pop back to the original directory.

chdir_p :: FilePath -> Sh a -> Sh a #

`chdir`, but first create the directory if it does not exit.

pwd :: Sh FilePath #

Obtain the current `Sh` working directory.

# Printing

echo :: Text -> Sh () #

Echo text to standard (error, when using `_err` variants) output. The `_n` variants do not print a final newline.

echo_n :: Text -> Sh () #

Echo text to standard (error, when using `_err` variants) output. The `_n` variants do not print a final newline.

echo_err :: Text -> Sh () #

Echo text to standard (error, when using `_err` variants) output. The `_n` variants do not print a final newline.

echo_n_err :: Text -> Sh () #

Echo text to standard (error, when using `_err` variants) output. The `_n` variants do not print a final newline.

echoWith :: (Text -> IO ()) -> Text -> Sh () #

Since: 1.12.1

inspect :: Show s => s -> Sh () #

`print` lifted into `Sh`.

inspect_err :: Show s => s -> Sh () #

A `print` lifted into `Sh` using stderr.

tag :: Sh a -> Text -> Sh a #

Same as `trace`, but for use in combinator style: `action `tag` message`.

trace :: Text -> Sh () #

Internally log what occurred. Log will be re-played on failure.

show_command :: FilePath -> [Text] -> Text #

# Querying filesystem

ls :: FilePath -> Sh [FilePath] #

List directory contents. Does not include `.` and `..`, but it does include (other) hidden files.

lsT :: FilePath -> Sh [Text] #

Get back `[Text]` instead of `[FilePath]`.

test_e :: FilePath -> Sh Bool #

Does a path point to an existing filesystem object?

test_f :: FilePath -> Sh Bool #

Does a path point to an existing file?

test_d :: FilePath -> Sh Bool #

Does a path point to an existing directory?

test_s :: FilePath -> Sh Bool #

Does a path point to a symlink?

test_px :: FilePath -> Sh Bool #

Test that a file is in the PATH and also executable

which :: FilePath -> Sh (Maybe FilePath) #

Get a full path to an executable by looking at the `PATH` environement variable. Windows normally looks in additional places besides the `PATH`: this does not duplicate that behavior.

# Filename helpers

absPath :: FilePath -> Sh FilePath #

Make a relative path absolute by combining with the working directory. An absolute path is returned as is. To create a relative path, use `relPath`.

(</>) :: (ToFilePath filepath1, ToFilePath filepath2) => filepath1 -> filepath2 -> FilePath #

Uses System.FilePath, but can automatically convert a `Text`.

(<.>) :: ToFilePath filepath => filepath -> Text -> FilePath #

Uses System.FilePath, but can automatically convert a `Text`.

canonic :: FilePath -> Sh FilePath #

Make an absolute path. Like `canonicalize`, but on an exception returns `absPath`.

canonicalize :: FilePath -> Sh FilePath #

Obtain a (reasonably) canonic file path to a filesystem object. Based on `canonicalizePath`.

relPath :: FilePath -> Sh FilePath #

Makes a relative path relative to the current `Sh` working directory. An absolute path is returned as is. To create an absolute path, use `absPath`.

relativeTo #

Arguments

:: FilePath | Anchor path, the prefix.
-> FilePath | Make this relative to anchor path.
-> Sh FilePath |

Make the second path relative to the first. Will canonicalize the paths if necessary.

path :: FilePath -> Sh FilePath #

Deprecated: use absPath, canonic, or relPath instead

hasExt :: Text -> FilePath -> Bool #

Flipped `hasExtension` for `Text`.

# Manipulating filesystem

mv :: FilePath -> FilePath -> Sh () #

Move a file. The second path could be a directory, in which case the original file is moved into that directory. wraps directory `renameFile`, which may not work across FS boundaries

rm :: FilePath -> Sh () #

Remove a file. Does fail if the file does not exist (use `rm_f` instead) or is not a file.

rm_f :: FilePath -> Sh () #

Remove a file. Does not fail if the file does not exist. Does fail if the file is not a file.

rm_rf :: FilePath -> Sh () #

A swiss army cannon for removing things. Actually this goes farther than a normal rm -rf, as it will circumvent permission problems for the files we own. Use carefully. Uses `removeDirectoryRecursive`

cp :: FilePath -> FilePath -> Sh () #

Copy a file. The second path could be a directory, in which case the original file name is used, in that directory.

cp_r :: FilePath -> FilePath -> Sh () #

Copy a file, or a directory recursively. Uses `cp`.

mkdir :: FilePath -> Sh () #

Create a new directory (fails if the directory exists).

mkdir_p :: FilePath -> Sh () #

Create a new directory, including parents (succeeds if the directory already exists).

mkdirTree :: Tree FilePath -> Sh () #

Create a new directory tree. You can describe a bunch of directories as a tree and this function will create all subdirectories. An example:

    exec = mkTree $
              "package" # [
                   "src" # [
                       "Data" # leaves ["Tree", "List", "Set", "Map"]
                   ],
                   "test" # leaves ["QuickCheck", "HUnit"],
                   "dist/doc/html" # []
               ]
            where (#) = Node
                  leaves = map (# [])

# reading/writing Files

readfile :: FilePath -> Sh Text #

readBinary :: FilePath -> Sh ByteString #

Wraps `readFile`.

writefile :: FilePath -> Text -> Sh () #

Write a `Text` to a file.

writeBinary :: FilePath -> ByteString -> Sh () #

appendfile :: FilePath -> Text -> Sh () #

Append a `Text` to a file.

touchfile :: FilePath -> Sh () #

Update a file, creating (a blank file) if it does not exist.

withTmpDir :: (FilePath -> Sh a) -> Sh a #

Create a temporary directory and pass it as a parameter to a `Sh` computation. The directory is nuked afterwards.

# exiting the program

exit :: Int -> Sh a #

``exit` 0` means no errors, all other codes are error conditions.

errorExit :: Text -> Sh a #

Echo a message and `exit` with status 1.

quietExit :: Int -> Sh a #

For exiting with status > 0 without printing debug information.

terror :: Text -> Sh a #

`fail` that takes a `Text`.

# Exceptions

bracket_sh :: Sh a -> (a -> Sh b) -> (a -> Sh c) -> Sh c #

catchany :: IO a -> (SomeException -> IO a) -> IO a #

A helper to catch any exception (same as `... `catch` (e :: SomeException) -> ...`).

catch_sh :: Exception e => Sh a -> (e -> Sh a) -> Sh a #

Same as a normal `catch` but specialized for the Sh monad.

handle_sh :: Exception e => (e -> Sh a) -> Sh a -> Sh a #

Same as a normal `handle` but specialized for the Sh monad.

handleany_sh :: (SomeException -> Sh a) -> Sh a -> Sh a #

Handle any exception in the `Sh` monad.

finally_sh :: Sh a -> Sh b -> Sh a #

Same as a normal `finally` but specialized for the `Sh` monad.

data ShellyHandler a #

You need to wrap exception handlers with this when using `catches_sh`.

Constructors

Exception e => ShellyHandler (e -> Sh a) |

catches_sh :: Sh a -> [ShellyHandler a] -> Sh a #

Same as a normal `catches`, but specialized for the `Sh` monad.

catchany_sh :: Sh a -> (SomeException -> Sh a) -> Sh a #

Catch any exception in the `Sh` monad.

data ReThrownException e #

Shelly's wrapper around exceptions thrown in its monad

Constructors

ReThrownException e String |

#### Instances

Instances details

Exception e => Exception (ReThrownException e) # |
Instance details Defined in Shelly Methods toException :: ReThrownException e -> SomeException # fromException :: SomeException -> Maybe (ReThrownException e) # displayException :: ReThrownException e -> String # backtraceDesired :: ReThrownException e -> Bool #
Exception e => Show (ReThrownException e) # |
Instance details Defined in Shelly Methods showsPrec :: Int -> ReThrownException e -> ShowS # show :: ReThrownException e -> String # showList :: [ReThrownException e] -> ShowS #

data RunFailed #

Constructors

RunFailed FilePath [Text] Int Text |

#### Instances

Instances details

Exception RunFailed # |
Instance details Defined in Shelly Methods toException :: RunFailed -> SomeException # fromException :: SomeException -> Maybe RunFailed # displayException :: RunFailed -> String # backtraceDesired :: RunFailed -> Bool #
Show RunFailed # |
Instance details Defined in Shelly Methods showsPrec :: Int -> RunFailed -> ShowS # show :: RunFailed -> String # showList :: [RunFailed] -> ShowS #

# convert between Text and FilePath

toTextIgnore :: FilePath -> Text #

toTextWarn :: FilePath -> Sh Text #

fromText :: Text -> FilePath #

Convert `Text` to a `FilePath`.

# Utility Functions

whenM :: Monad m => m Bool -> m () -> m () #

A monadic-conditional version of the `when` guard.

unlessM :: Monad m => m Bool -> m () -> m () #

A monadic-conditional version of the `unless` guard.

time :: Sh a -> Sh (Double, a) #

Run a `Sh` computation and collect timing information. The value returned is the amount of *real* time spent running the computation in seconds, as measured by the system clock. The precision is determined by the resolution of `getCurrentTime`.

sleep :: Int -> Sh () #

`threadDelay` wrapper that uses seconds.

# Re-exported for your convenience

liftIO :: MonadIO m => IO a -> m a #

Lift a computation from the `IO` monad. This allows us to run IO computations in any monadic stack, so long as it supports these kinds of operations (i.e. `IO` is the base monad for the stack).

### Example

Expand

    import Control.Monad.Trans.State -- from the "transformers" library

    printState :: Show s => StateT s IO ()
    printState = do
      state <- get
      liftIO $ print state

Had we omitted ``liftIO``, we would have ended up with this error:

    • Couldn't match type ‘IO’ with ‘StateT s IO’
     Expected type: StateT s IO ()
       Actual type: IO ()

The important part here is the mismatch between `StateT s IO ()` and ``IO` ()`.

Luckily, we know of a function that takes an ``IO` a` and returns an `(m a)`: ``liftIO``, enabling us to run the program and see the expected results:

    > evalStateT printState "hello"
    "hello"

    > evalStateT printState 3
    3

when :: Applicative f => Bool -> f () -> f () #

Conditional execution of `Applicative` expressions. For example,

#### Examples

Expand

    when debug (putStrLn "Debugging")

will output the string `Debugging` if the Boolean value `debug` is `True`, and otherwise do nothing.

    >>> putStr "pi:" >> when False (print 3.14159)
    pi:

unless :: Applicative f => Bool -> f () -> f () #

The reverse of `when`.

#### Examples

Expand

    >>> do x <- getLine
           unless (x == "hi") (putStrLn "hi!")
    comingupwithexamplesisdifficult
    hi!

    >>> unless (pi > exp 1) Nothing
    Just ()

type FilePath = String #

File and directory names are values of type `String`, whose precise meaning is operating system dependent. Files can be opened, yielding a handle which can then be used to operate on the contents of that file.

(<$>) :: Functor f => (a -> b) -> f a -> f b infixl 4 #

An infix synonym for `fmap`.

The name of this operator is an allusion to `$`. Note the similarities between their types:

     ($)  ::              (a -> b) ->   a ->   b
    (<$>) :: Functor f => (a -> b) -> f a -> f b

Whereas `$` is function application, `<$>` is function application lifted over a `Functor`.

#### Examples

Expand

Convert from a ``Maybe` `Int`` to a ``Maybe` `String`` using `show`:

    >>> show <$> Nothing
    Nothing

    >>> show <$> Just 3
    Just "3"

Convert from an ``Either` `Int` `Int`` to an ``Either` `Int`` `String` using `show`:

    >>> show <$> Left 17
    Left 17

    >>> show <$> Right 17
    Right "17"

Double each element of a list:

    >>> (*2) <$> [1,2,3]
    [2,4,6]

Apply `even` to the second element of a pair:

    >>> even <$> (2,2)
    (2,True)

# internal functions for writing extensions

get :: Sh State #

put :: State -> Sh () #

# find functions

find :: FilePath -> Sh [FilePath] #

List directory recursively (like the POSIX utility "find"). listing is relative if the path given is relative. If you want to filter out some results or fold over them you can do that with the returned files. A more efficient approach is to use one of the other find functions.

findWhen :: (FilePath -> Sh Bool) -> FilePath -> Sh [FilePath] #

`find` that filters the found files as it finds. Files must satisfy the given filter to be returned in the result.

findFold :: (a -> FilePath -> Sh a) -> a -> FilePath -> Sh a #

Fold an arbitrary folding function over files froma a `find`. Like `findWhen` but use a more general fold rather than a filter.

findDirFilter :: (FilePath -> Sh Bool) -> FilePath -> Sh [FilePath] #

`find` that filters out directories as it finds. Filtering out directories can make a find much more efficient by avoiding entire trees of files.

findDirFilterWhen #

Arguments

:: (FilePath -> Sh Bool) | directory filter
-> (FilePath -> Sh Bool) | file filter
-> FilePath | directory
-> Sh [FilePath] |

Similar to `findWhen`, but also filter out directories. Alternatively, similar to `findDirFilter`, but also filter out files. Filtering out directories makes the find much more efficient.

findFoldDirFilter :: (a -> FilePath -> Sh a) -> a -> (FilePath -> Sh Bool) -> FilePath -> Sh a #

Like `findDirFilterWhen` but use a folding function rather than a filter. The most general finder: you likely want a more specific one.

followSymlink :: Bool -> Sh a -> Sh a #

`find`-command follows symbolic links. Defaults to `False`. When `True`, follow symbolic links. When `False`, never follow symbolic links.