[Haskell-cafe] Inject cabal version or VCS version as a CPP macro
michael at snoyman.com
Wed Feb 22 09:40:42 CET 2012
I have a project at work that embeds the Mercurial version in the
final executable. I use Template Haskell to call the hg executable and
parse its output. Here's the relevant code snippet:
putStrLn $ "Mercurial commit: " ++ $(do
let getChangeset s =
let (k, v') = break (== ':') s
v = dropWhile isSpace $ drop 1 v'
in if k == "changeset" then Just v else Nothing
res <- qRunIO $ readProcess "hg" ["heads"] ""
let cs = mapMaybe getChangeset $ lines res
lift $ case cs of
x:_ -> x
 -> "unknown")
On Wed, Feb 22, 2012 at 10:37 AM, Eugene Kirpichov <ekirpichov at gmail.com> wrote:
> Thanks, this is exactly what I was looking for!
> I might look some more into exposing VCS tags too, however.
> On Wed, Feb 22, 2012 at 12:25 PM, Roel van Dijk <vandijk.roel at gmail.com>
>> For each package "myPackage" Cabal generates a module containing,
>> among other things, the package's version as a Haskell value:
>> > import Paths_myPackage ( version )
>> > import Data.Version ( showVersion )
>> > main = showVersion version
>> See also "Accessing data files from package code" in
>> I do not now how to expose information from the VCS.
>> 2012/2/22 Eugene Kirpichov <ekirpichov at gmail.com>:
>> > Hi,
>> > I'd like my program to print something like "this is $program 1.0.4 git
>> > 45fea6b" when invoked with --version, or at least just the 1.0.4 part.
>> > Can Cabal expose the version as a preprocessor macro by default, or do I
>> > have to use Build-Type: Custom and add a preprocessing step of my own?
> Eugene Kirpichov
> Principal Engineer, Mirantis Inc. http://www.mirantis.com/
> Editor, http://fprog.ru/
> Haskell-Cafe mailing list
> Haskell-Cafe at haskell.org
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