diff options
| -rw-r--r-- | debian/changelog | 2 | ||||
| -rw-r--r-- | src/Propellor/Property/File.hs | 40 |
2 files changed, 42 insertions, 0 deletions
diff --git a/debian/changelog b/debian/changelog index 0e5aa8d5..30af1b88 100644 --- a/debian/changelog +++ b/debian/changelog @@ -10,6 +10,8 @@ propellor (3.2.4) UNRELEASED; urgency=medium Thanks, Sean Whitton. * stack.yaml: Compile with GHC 8.0.1 against lts-7.16. Thanks, Andrew Cowie. + * Added Propellor.Property.File.configFileName and related functions + to generate good filenames for config directories. -- Joey Hess <id@joeyh.name> Sat, 24 Dec 2016 15:06:36 -0400 diff --git a/src/Propellor/Property/File.hs b/src/Propellor/Property/File.hs index 95fc6f81..fe2b1057 100644 --- a/src/Propellor/Property/File.hs +++ b/src/Propellor/Property/File.hs @@ -8,6 +8,7 @@ import Utility.FileMode import qualified Data.ByteString.Lazy as L import System.Posix.Files import System.Exit +import Data.Char type Line = String @@ -221,3 +222,42 @@ viaStableTmp a f = bracketIO setup cleanup go go tmpfile = do a tmpfile liftIO $ rename tmpfile f + +-- | Generates a base configuration file name from a String, which +-- can be put in a configuration directory, such as +-- /etc/apt/sources.list.d/ +-- +-- The generated file name is limited to using ASCII alphanumerics, +-- '_' and '.', so that programs that only accept a limited set of +-- characters will accept it. Any other characters will be encoded +-- in escaped form. +-- +-- Some file extensions, such as ".dpkg-new" may be filtered out by +-- programs that use configuration directories. To avoid such problems, +-- it's a good idea to add an static prefix and extension to the +-- result of this function. For example: +-- +-- > aptSource foo = "/etc/apt/sources.list.d" </> "propellor_" ++ configFileName foo <.> ".conf" +configFileName :: String -> FilePath +configFileName = concatMap escape + where + escape c + | isAscii c && isAlphaNum c = [c] + | c == '.' = [c] + | otherwise = '_' : show (ord c) + +-- | Applies configFileName to any value that can be shown. +showConfigFileName :: Show v => v -> FilePath +showConfigFileName = configFileName . show + +-- | Inverse of showConfigFileName. +readConfigFileName :: Read v => FilePath -> Maybe v +readConfigFileName = readish . unescape + where + unescape [] = [] + unescape ('_':cs) = case break (not . isDigit) cs of + ([], _) -> '_' : unescape cs + (ns, cs') -> case readish ns of + Nothing -> '_' : ns ++ unescape cs' + Just n -> chr n : unescape cs' + unescape (c:cs) = c : unescape cs |