rexe - Executable forwarder for Windows

On Windows, you can't overwrite a running binary. That means if you are writing a long running developer tool (e.g. ghcid in my case), it's hard to use that tool to develop itself. The rexe program solves that.

Using rexe

If you want to use rexe to allow overwriting a binary (we'll use ghcid as an example):

1. Get a copy of rexe from here.
2. put that copy of rexe.exe on your %PATH%, before the real ghcid.exe.
3. Rename that copy fo rexe.exe to ghcid.exe.

Now running ghcid will run the ghcid.exe which is really rexe.exe. What rexe does is find the next similarly named binary, copy it to a temporary location, and run it. As a consequence, you can now overwrite the real ghcid.exe, since it's not actually running.

To compile the code run ghc rexe.hs, but unless you are changing rexe, it's easier to use a precompiled binary.