My apologies, I missed this: On 08/02/2012 21:25, Evan Laforge wrote:
% git diff HEAD\^ diff --git a/System/Process.hs b/System/Process.hs index f3a8f9b..a372228 100644 --- a/System/Process.hs +++ b/System/Process.hs @@ -234,9 +234,18 @@ To create a pipe from which to read the output of @ls@: To also set the directory in which to run @ls@:
(_, Just hout, _, _)<- -> createProcess (proc "ls" []){ cwd = Just "\home\bob", +> createProcess (proc "ls" []){ cwd = Just "/home/bob", std_out = CreatePipe }
+Note that this does /not/ throw an error if the binary is not found, +or not executable. Instead, the process will fail with the exit code 127. +But you can't rely on it failing quickly, because it may e.g. hang up +searching the PATH on a slow NFS mount. Since there's no way to tell when +the exec() has succeeded, the only way to reliably know if the createProcess +failed is to 'waitForProcess'. + +If the CreateProcess record's 'cwd' directory doesn't exist, the exit code +will be 126. -}
This isn't true on Windows, so at least the comment should be qualified to that effect.
createProcess :: CreateProcess diff --git a/System/Process/Internals.hs b/System/Process/Internals.hs index 11de1f4..2a6c047 100644 --- a/System/Process/Internals.hs +++ b/System/Process/Internals.hs @@ -199,7 +199,8 @@ data CmdSpec = ShellCommand String -- ^ a command line to execute using the shell | RawCommand FilePath [String] - -- ^ the filename of an executable with a list of arguments + -- ^ The filename of an executable with a list of arguments. + -- The PATH is searched for the executable.
Again, I think Windows has a rather more complex method for finding binaries, and in all cases it makes a difference whether the FilePath is absolute or not. I forget the precise details. The best way forward with this is to fix up the patch and submit it as a GHC ticket. Cheers, Simon