executable-hash

Provides the SHA1 hash of the executable. This hash can either be injected into the executable as a step after compilation, or calculated at runtime.

Usage

The main function expected to be used by the user is System.Executable.Hash.executableHash. When used in a TH splice, like $(executableHash), the resulting expression yields a SHA1 hash determined by the contents of the executable. However, note that this may not be the actual SHA1 of the executable, since the hash can be injected into the executable (which changes its “actual” hash).

Installing this package will also install the inject-executable-hash executable. Running this program on a binary, like inject-executable-hash <binary-name> will replace a dummy ByteString (via the file-embed package) in the binary with its hash.

Alternatively, you can put this in a Setup.hs file, and set build-type: Custom in your .cabal:

import Distribution.Simple (defaultMainWithHooks, simpleUserHooks, postBuild)
import Distribution.Simple.LocalBuildInfo (buildDir)
import System.Executable.Hash.Internal (maybeInjectExecutableHash)
import System.FilePath ((</>))

main :: IO ()
main = defaultMainWithHooks $ simpleUserHooks
    { postBuild = \_ _ _ buildInfo ->
        maybeInjectExecutableHash (buildDir buildInfo </> "exeName/exeName")
    }

(Note: you’ll need to change the executable path)