Re: ghc/haskell tool registry

Hi, registry sounds like overkill to me. If really an absolute hardcoded path is needed, I would appreciate if it is stored only in a single place (for ghc, ghci, ghc-pkg and package.conf). Other tools have a "relocate" script, that only changes that location after unpacking (or move). Cheers Christian Claus Reinke wrote:

may i suggest a different approach? most shells have commands to list programs in PATH beyond the first match, such as 'whereis ssh', 'which -a ssh', or 'type -a ssh'. now, this won't help directly because the ghc tool in question might not be on the PATH.

but as this issue is so widespread, one could extend one of the existing haskell package registries (ghc-pkg, cabal) to cover haskell tools as well. every haskell tool would know how to register itself with its current location, and how to query the haskell tool registry for the location of other tools (preferably from the same build/version). since we're on the ghc list:

ghc-tools (un-)register <path>/ghc<version> ghc-tools list ghc<version> ghc-tools describe runhaskell ghc-tools field location ghc-6.9 ghc-tools field user_guide ghc-6.9 ..

pros:

- knowing your version would be sufficient to find all the tools from your bundle - finding all available haskell tools would be easy

downsides: - tools would have to register themselves after installation/relocation, and unregister during uninstall - there is no single ghc-pkg/cabal instance to choose, but multiple versions..

the former is no worse than for packages, the latter is a runhaskell-style issue: we want a single ghc-tools in the path, but we don't care who provides it.

claus

----- Original Message ----- From: "Simon Marlow" To: "Christian Maeder" Cc: "Manuel M T Chakravarty" ; "GHC List" Sent: Monday, November 19, 2007 9:35 AM Subject: Re: GHC 6.8.1 on Mac OS X 10.5 (Leopard)

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Christian Maeder wrote:

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Ian Lynagh wrote:

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Is there a way for GHC on OS X to find where it was run from, so that it can find package.conf? The command:

ghc --print-libdir

should do it. But the way that knows what to print on unix machines is that ghc is a shell script wrapper which passes -B<libdir> to the real GHC binary. If you want to be able to move GHC around then the wrapper can't have the

On Sat, Nov 17, 2007 at 03:02:55PM +0000, C.M.Brown wrote: path hardcoded.

The wrapper could call `pwd` to find out the current path.

pwd gives you the directory that the script was invoked *from*, not the directory in which the script resides. This is a common problem on Unix: there's no general way to find out the location of a binary.

Well that's not entirely true. On Linux you have /proc/<pid>/exe, and on Solaris you have getexecname(). Does MacOS X have anything?

Cheers, Simon _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users