Portability	portable
Maintainer	cabal-devel@haskell.org

Distribution.Simple.Program

Contents

Program and functions for constructing them
Configured program and related functions
Program invocations
The collection of unconfigured and configured progams
The collection of configured programs we can run
Programs that Cabal knows about
deprecated

Description

This provides an abstraction which deals with configuring and running programs. A Program is a static notion of a known program. A ConfiguredProgram is a Program that has been found on the current machine and is ready to be run (possibly with some user-supplied default args). Configuring a program involves finding its location and if necessary finding its version. There is also a ProgramConfiguration type which holds configured and not-yet configured programs. It is the parameter to lots of actions elsewhere in Cabal that need to look up and run programs. If we had a Cabal monad, the ProgramConfiguration would probably be a reader or state component of it.

The module also defines all the known built-in Programs and the defaultProgramConfiguration which contains them all.

One nice thing about using it is that any program that is registered with Cabal will get some "configure" and ".cabal" helpers like --with-foo-args --foo-path= and extra-foo-args.

There's also good default behavior for trying to find "foo" in PATH, being able to override its location, etc.

There's also a hook for adding programs in a Setup.lhs script. See hookedPrograms in Distribution.Simple.UserHooks. This gives a hook user the ability to get the above flags and such so that they don't have to write all the PATH logic inside Setup.lhs.

Synopsis

Program and functions for constructing them

data Program Source

Represents a program which can be configured.

Constructors

Program

Fields

programName :: String: The simple name of the program, eg. ghc
programFindLocation :: Verbosity -> IO (Maybe FilePath): A function to search for the program if it's location was not specified by the user. Usually this will just be a
programFindVersion :: Verbosity -> FilePath -> IO (Maybe Version): Try to find the version of the program. For many programs this is not possible or is not necessary so it's ok to return Nothing.
programPostConf :: Verbosity -> ConfiguredProgram -> IO [ProgArg]: A function to do any additional configuration after we have located the program (and perhaps identified its version). It is allowed to return additional flags that will be passed to the program on every invocation.

simpleProgram :: String -> Program Source

Make a simple named program.

By default we'll just search for it in the path and not try to find the version name. You can override these behaviours if necessary, eg:

 simpleProgram "foo" { programFindLocation = ... , programFindVersion ... }

findProgramLocation :: Verbosity -> FilePath -> IO (Maybe FilePath)Source

Look for a program on the path.

findProgramVersion Source

Arguments

:: String	version args
-> (String -> String)	function to select version number from program output
-> Verbosity
-> FilePath	location
-> IO (Maybe Version)

Look for a program and try to find it's version number. It can accept either an absolute path or the name of a program binary, in which case we will look for the program on the path.

Configured program and related functions

data ConfiguredProgram Source

Constructors

ConfiguredProgram

Fields

programId :: String: Just the name again
programVersion :: Maybe Version: The version of this program, if it is known.
programDefaultArgs :: [String]: Default command-line args for this program. These flags will appear first on the command line, so they can be overridden by subsequent flags.
programOverrideArgs :: [String]: Override command-line args for this program. These flags will appear last on the command line, so they override all earlier flags.
programLocation :: ProgramLocation: Location of the program. eg. /usr/bin/ghc-6.4

Instances

Eq ConfiguredProgram
Read ConfiguredProgram
Show ConfiguredProgram

programPath :: ConfiguredProgram -> FilePath Source

The full path of a configured program.

type ProgArg = String Source

data ProgramLocation Source

Where a program was found. Also tells us whether it's specifed by user or not. This includes not just the path, but the program as well.

Constructors

UserSpecified	The user gave the path to this program, eg. --ghc-path=/usr/bin/ghc-6.6
Fields locationPath :: FilePath
FoundOnSystem	The location of the program, as located by searching PATH.
Fields locationPath :: FilePath

Instances

Eq ProgramLocation
Read ProgramLocation
Show ProgramLocation

runProgram Source

Arguments

:: Verbosity	Verbosity
-> ConfiguredProgram	The program to run
-> [ProgArg]	Any extra arguments to add
-> IO ()

Runs the given configured program.

getProgramOutput Source

Arguments

:: Verbosity	Verbosity
-> ConfiguredProgram	The program to run
-> [ProgArg]	Any extra arguments to add
-> IO String

Runs the given configured program and gets the output.

Program invocations

data ProgramInvocation Source

Represents a specific invocation of a specific program.

This is used as an intermediate type between deciding how to call a program and actually doing it. This provides the opportunity to the caller to adjust how the program will be called. These invocations can either be run directly or turned into shell or batch scripts.

Constructors

ProgramInvocation
Fields progInvokePath :: FilePath progInvokeArgs :: [String] progInvokeEnv :: [(String, String)] progInvokeCwd :: Maybe FilePath progInvokeInput :: Maybe String progInvokeInputEncoding :: IOEncoding progInvokeOutputEncoding :: IOEncoding

emptyProgramInvocation :: ProgramInvocation Source

simpleProgramInvocation :: FilePath -> [String] -> ProgramInvocation Source

programInvocation :: ConfiguredProgram -> [String] -> ProgramInvocation Source

runProgramInvocation :: Verbosity -> ProgramInvocation -> IO ()Source

getProgramInvocationOutput :: Verbosity -> ProgramInvocation -> IO String Source

The collection of unconfigured and configured progams

builtinPrograms :: [Program]Source

The default list of programs. These programs are typically used internally to Cabal.

The collection of configured programs we can run

type ProgramConfiguration = ProgramDb Source

emptyProgramConfiguration, defaultProgramConfiguration :: ProgramConfiguration Source

restoreProgramConfiguration :: [Program] -> ProgramConfiguration -> ProgramConfiguration Source

addKnownProgram :: Program -> ProgramDb -> ProgramDb Source

Add a known program that we may configure later

addKnownPrograms :: [Program] -> ProgramDb -> ProgramDb Source

lookupKnownProgram :: String -> ProgramDb -> Maybe Program Source

knownPrograms :: ProgramDb -> [(Program, Maybe ConfiguredProgram)]Source

userSpecifyPath Source

Arguments

:: String	Program name
-> FilePath	user-specified path to the program
-> ProgramDb
-> ProgramDb

User-specify this path. Basically override any path information for this program in the configuration. If it's not a known program ignore it.

userSpecifyPaths :: [(String, FilePath)] -> ProgramDb -> ProgramDb Source

Like userSpecifyPath but for a list of progs and their paths.

userMaybeSpecifyPath :: String -> Maybe FilePath -> ProgramDb -> ProgramDb Source

userSpecifyArgs Source

Arguments

:: String	Program name
-> [ProgArg]	user-specified args
-> ProgramDb
-> ProgramDb

User-specify the arguments for this program. Basically override any args information for this program in the configuration. If it's not a known program, ignore it..

userSpecifyArgss :: [(String, [ProgArg])] -> ProgramDb -> ProgramDb Source

Like userSpecifyPath but for a list of progs and their args.

userSpecifiedArgs :: Program -> ProgramDb -> [ProgArg]Source

Get any extra args that have been previously specified for a program.

lookupProgram :: Program -> ProgramDb -> Maybe ConfiguredProgram Source

Try to find a configured program

updateProgram :: ConfiguredProgram -> ProgramDb -> ProgramDb Source

Update a configured program in the database.

configureProgram :: Verbosity -> Program -> ProgramDb -> IO ProgramDb Source

Try to configure a specific program. If the program is already included in the colleciton of unconfigured programs then we use any user-supplied location and arguments. If the program gets configured sucessfully it gets added to the configured collection.

Note that it is not a failure if the program cannot be configured. It's only a failure if the user supplied a location and the program could not be found at that location.

The reason for it not being a failure at this stage is that we don't know up front all the programs we will need, so we try to configure them all. To verify that a program was actually sucessfully configured use requireProgram.

configureAllKnownPrograms :: Verbosity -> ProgramDb -> IO ProgramDb Source

Try to configure all the known programs that have not yet been configured.

reconfigurePrograms :: Verbosity -> [(String, FilePath)] -> [(String, [ProgArg])] -> ProgramDb -> IO ProgramDb Source

reconfigure a bunch of programs given new user-specified args. It takes the same inputs as userSpecifyPath and userSpecifyArgs and for all progs with a new path it calls configureProgram.

requireProgram :: Verbosity -> Program -> ProgramDb -> IO (ConfiguredProgram, ProgramDb)Source

Check that a program is configured and available to be run.

It raises an exception if the program could not be configured, otherwise it returns the configured program.

requireProgramVersion :: Verbosity -> Program -> VersionRange -> ProgramDb -> IO (ConfiguredProgram, Version, ProgramDb)Source

Check that a program is configured and available to be run.

Additionally check that the version of the program number is suitable and return it. For example you could require AnyVersion or orLaterVersion (Version [1,0] [])

It raises an exception if the program could not be configured or the version is unsuitable, otherwise it returns the configured program and its version number.

runDbProgram Source

Arguments