git-annex/Annex/Path.hs

36 lines
1 KiB
Haskell

{- git-annex program path
-
- Copyright 2013 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Path where
import Common
import Config.Files
import Utility.Env
import System.Environment (getExecutablePath)
{- A fully qualified path to the currently running git-annex program.
-
- getExecutablePath is used when possible. On OSs it supports
- well, it returns the complete path to the program. But, on other OSs,
- it might return just the basename. Fall back to reading the programFile,
- or searching for the command name in PATH.
-
- The standalone build runs git-annex via ld.so, and defeats
- getExecutablePath. It sets GIT_ANNEX_PROGRAMPATH to the correct path
- to the wrapper script to use.
-}
programPath :: IO FilePath
programPath = go =<< getEnv "GIT_ANNEX_PROGRAMPATH"
where
go (Just p) = return p
go Nothing = do
exe <- getExecutablePath
p <- if isAbsolute exe
then return exe
else readProgramFile
maybe cannotFindProgram return =<< searchPath p