-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/
-- | Determine the type of an image by reading the first bytes.
--
-- A package used to determine the type of an image according to its
-- first bytes based on the Python library imghdr.
--
-- Most simplest usage is getting the type of a file:
--
--
-- >>> import Codec.ImageType
--
-- >>> getFileType "/tmp/mystery_file"
-- Just "webp"
--
--
-- Or to test for a specific extension:
--
--
-- >>> isPgm "/tmp/file.pgm"
-- True
--
-- >>> import qualified Data.ByteString as B
--
-- >>> testPgm <$> B.readFile "/tmp/file.pgm"
-- Just "pgm"
--
--
-- Or to filter files by extension:
--
--
-- >>> import Codec.ImageType
--
-- >>> import Control.Monad
--
-- >>> import System.Directory
--
-- >>>
--
-- >>> getDirectoryContents "." >>= filterM doesFileExist >>= filterM isJpeg
-- ["file2.jpeg","file1.jpeg"]
--
--
-- Supports the following extensions: JPEG, PNG,
-- GIF, TIFF, RGB, PBM, PGM,
-- PPM, RAST, XBM, BMP,
-- WebP, EXR.
@package image-type
@version 0.1.0.0
-- | Infers an image's type by looking at its initial values and comparing
-- against some magic bytes:
--
--
-- >>> :set -XOverloadedStrings
--
-- >>> import Codec.ImageType
--
-- >>> import System.IO
--
-- >>> import qualified Data.ByteString as B
--
-- >>>
--
-- >>> h <- openFile "/tmp/1_webp_ll.webp" ReadMode
--
-- >>> bytes <- hGet h 32
--
-- >>> B.isInfixOf "RIFF" bytes
-- True
--
-- >>> bytes
-- "RIFF\144h\SOH\NULWEBPVP8L\131h\SOH\NUL/\143\SOHK\DLE\141\&8l\219F\146\224"
--
-- >>> getFileType "/tmp/1_webp_ll.webp"
-- Just "webp"
--
--
-- Some other examples:
--
--
-- >>> import System.Process
--
-- >>> import System.Directory
--
-- >>> import Control.Monad
--
-- >>> let findTiffs = lines <$> readProcess "locate" ["*.tiff"] ""
--
-- >>> length <$> findTiffs
-- 25
--
-- >>> findTiffs >>= filterM doesFileExist >>= mapM getFileType
-- [Just "tiff",Just "tiff", …
--
-- >>> sequence_ <$> (findTiffs >>= filterM doesFileExist >>= mapM getFileType)
-- Just ()
--
module Codec.ImageType
-- | Gets a ginel possible file types based on fairly arbitrary tie
-- breaking.
--
--
-- >>> import System.Directory
--
-- >>> import Control.Monad
--
-- >>> getDirectoryContents "." >>= filterM doesFileExist >>= mapM getFileType
-- [Just "rast",Just "jpeg",Nothing,Just "webp",Just "gif",Just "pgm",Just "webp",Nothing,Just "webp",Just "exr"]
--
getFileType :: FilePath -> IO (Maybe String)
-- | Gets possible file types. Returns empty list if nothing is found,
-- otherwise a list of matches.
--
--
-- >>> import System.Directory
--
-- >>> import Control.Monad
--
-- >>> getDirectoryContents "." >>= filterM doesFileExist >>= mapM getFileTypes
-- [["rast"],["jpeg"],[],["webp"],["gif"],["pgm"],["webp"],[],["webp"],["exr"]]
--
getFileTypes :: FilePath -> IO [String]
-- | Checks if file is jpeg.
--
--
-- >>> import Codec.ImageType
--
-- >>> import Control.Monad
--
-- >>> import System.Directory
--
-- >>>
--
-- >>>
--
-- >>> getDirectoryContents "." >>= filterM doesFileExist >>= filterM isJpeg
-- ["file2.jpeg","file1.jpeg"]
--
isJpeg :: FilePath -> IO Bool
-- | Checks if file is png.
isPng :: FilePath -> IO Bool
-- | Checks if file is gif.
isGif :: FilePath -> IO Bool
-- | Checks if file is tiff.
isTiff :: FilePath -> IO Bool
-- | Checks if file is rgb.
isRgb :: FilePath -> IO Bool
-- | Checks if file is pbm.
isPbm :: FilePath -> IO Bool
-- | Checks if file is pgm.
isPgm :: FilePath -> IO Bool
-- | Checks if file is ppm.
isPpm :: FilePath -> IO Bool
-- | Checks if file is rast.
isRast :: FilePath -> IO Bool
-- | Checks if file is xbm.
isXbm :: FilePath -> IO Bool
-- | Checks if file is bmp.
isBmp :: FilePath -> IO Bool
-- | Checks if file is webp.
isWebp :: FilePath -> IO Bool
-- | Checks if file is exr.
isExr :: FilePath -> IO Bool
-- | Joint Photographic Experts Group (JPEG). Returns Just
-- jpeg if file satisfies check.
testJpeg :: ByteString -> Maybe String
-- | Portable Network Graphics (PNG). Returns Just png if
-- file satisfies check against magic number 89 50 4e 47 0d 0a 1a
-- 0a.
testPng :: ByteString -> Maybe String
-- | Graphics Interchange Format (GIF). Returns Just gif if
-- file satisfies check against magic number GIF87a and
-- GIF89a.
testGif :: ByteString -> Maybe String
-- | Tagged Image File Format (TIFF). Returns Just tiff if
-- first short is II or MM.
testTiff :: ByteString -> Maybe String
-- | SGI image library. Checks magic number (decimal value 474 as a short)
-- that identifies file as an SGI image file and then returns Just
-- rgb.
testRgb :: ByteString -> Maybe String
-- | PBM (portable bitmap). Returns Just pbm if file
-- satisfies check.
testPbm :: ByteString -> Maybe String
-- | PGM (portable graymap). Returns Just pgm if file
-- satisfies check.
testPgm :: ByteString -> Maybe String
-- | PPM (portable pixmap). Returns Just ppm if file
-- satisfies check.
testPpm :: ByteString -> Maybe String
-- | Sun raster file. Returns Just rast if file satisfies
-- check.
testRast :: ByteString -> Maybe String
-- | X bitmap (X10 or X11). Returns Just xbm if file
-- satisfies check.
testXbm :: ByteString -> Maybe String
-- | Bitmap (BMP) file format. Returns Just bmp if file
-- satisfies check.
testBmp :: ByteString -> Maybe String
-- | WebP. Returns Just webp if file satisfies check.
testWebp :: ByteString -> Maybe String
-- | OpenEXR. Returns Just exr if file satisfies check.
testExr :: ByteString -> Maybe String