diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Copyright (c) 2014, Pat Brisbin + +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the following + disclaimer in the documentation and/or other materials provided + with the distribution. + + * Neither the name of Pat Brisbin nor the names of other + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/load-env.cabal b/load-env.cabal new file mode 100644 --- /dev/null +++ b/load-env.cabal @@ -0,0 +1,40 @@ +Name: load-env +Version: 0.0.1 +Author: Pat Brisbin +Maintainer: Pat Brisbin +License: BSD3 +License-File: LICENSE +Synopsis: Load environment variables from a file. +Description: Parse a .env file and load any declared variables into + the current process's environment. This allows for a + .env file to specify development-friendly defaults for + configuration values normally set in the deployment + environment. +Cabal-Version: >= 1.10 +Build-Type: Simple + +Library + Default-Language: Haskell2010 + HS-Source-Dirs: src + GHC-Options: -Wall + Exposed-Modules: LoadEnv + , LoadEnv.Parse + Build-Depends: base >= 4.6.0 && < 5 + , parsec + +Test-Suite spec + Type: exitcode-stdio-1.0 + Default-Language: Haskell2010 + Hs-Source-Dirs: test + Ghc-Options: -Wall + Main-Is: Spec.hs + Build-Depends: base + , load-env + , directory + , hspec + , HUnit + , parsec + +Source-Repository head + Type: git + Location: https://github.com/pbrisbin/load-env diff --git a/src/LoadEnv.hs b/src/LoadEnv.hs new file mode 100644 --- /dev/null +++ b/src/LoadEnv.hs @@ -0,0 +1,38 @@ +module LoadEnv + ( loadEnv + , loadEnvFrom + ) where + + +import System.Environment (setEnv) +import Text.Parsec.String (parseFromFile) + +import LoadEnv.Parse + +-- | +-- +-- Parse @./.env@ for variable declariations. Set those variables in the +-- currently running process's environment. Variables can be declared in the +-- following form: +-- +-- > FOO=bar +-- > FOO="bar" +-- > FOO='bar' +-- +-- Declarations may optionally be preceded by @export@, which will be ignored. +-- Lines beginning with @#@ and blank lines are ignored. Trailing whitespace is +-- ignored. Quotes inside quoted values or spaces in unquoted values must be +-- escaped with a backlash. All else will result in a parse error being printed +-- to @stdout@. +-- +-- If you wish to specify your own file, use @'loadEnvFrom'@. If you wish to +-- pass your own string or work with the parse result directly, use the +-- lower-level functions available in @"System.Env.Parse"@. +-- +loadEnv :: IO () +loadEnv = loadEnvFrom ".env" + +loadEnvFrom :: FilePath -> IO () +loadEnvFrom fp = + parseFromFile parseEnvironment fp >>= either + (putStrLn . show) (mapM_ $ uncurry setEnv) diff --git a/src/LoadEnv/Parse.hs b/src/LoadEnv/Parse.hs new file mode 100644 --- /dev/null +++ b/src/LoadEnv/Parse.hs @@ -0,0 +1,67 @@ +module LoadEnv.Parse + ( Environment + , Variable + , parseEnvironment + , parseVariable + ) where + +import Control.Applicative ((<$>), (<*>)) +import Data.Maybe (catMaybes) + +import Text.Parsec +import Text.Parsec.String + +type Environment = [Variable] +type Variable = (String, String) + +parseEnvironment :: Parser Environment +parseEnvironment = fmap catMaybes $ many1 parseLine + +parseLine :: Parser (Maybe Variable) +parseLine = try (fmap Just $ parseVariable) <|> ignoreLine + +ignoreLine :: Parser (Maybe Variable) +ignoreLine = (commentLine <|> blankLine) >> return Nothing + +commentLine :: Parser () +commentLine = do + _ <- spaces + _ <- char '#' + _ <- manyTill anyToken (char '\n') + + return () + +blankLine :: Parser () +blankLine = many1 space >> return () + +parseVariable :: Parser Variable +parseVariable = (,) <$> identifier <*> value + +identifier :: Parser String +identifier = do + optional $ between spaces spaces $ string "export" + + i <- many1 letter + _ <- char '=' + + return i + +value :: Parser String +value = do + v <- quotedValue <|> unquotedValue <|> return "" + _ <- many $ oneOf " \t" + _ <- char '\n' + + return v + +quotedValue :: Parser String +quotedValue = do + q <- oneOf "'\"" + + manyTill (try (escaped q) <|> anyToken) (char q) + +unquotedValue :: Parser String +unquotedValue = many1 $ try (escaped ' ') <|> (noneOf "\"' \n") + +escaped :: Char -> Parser Char +escaped c = string ("\\" ++ [c]) >> return c diff --git a/test/Spec.hs b/test/Spec.hs new file mode 100644 --- /dev/null +++ b/test/Spec.hs @@ -0,0 +1,1 @@ +{-# OPTIONS_GHC -F -pgmF hspec-discover #-}