From: Lennon Day-Reynolds <rcoder@...>
Date: 2004-08-23T06:52:59+09:00
Subject: Embedded Ruby and stdin

I'm working on a simple wrapper which embeds the Ruby runtime and a
script file into a single binary. The idea is to have something much
like Exerb, but platform-independent (i.e., works anywhere Ruby does).
It reads the size and offset of an included script from the last few
bytes of the program binary, closes stdin and reopens it as a handle
to argv[0], and seeks to the script offset before initializing Ruby.

Everything goes fine until I call ruby_options(argv, argc), at which
point I get an Errno::EINVAL exception. Does anyone with a little more
experience working with the Ruby core have any suggestions for why
this could be happening? I know that the filehandle is valid, since I
do a number of I/O ops on it from C before passing control to Ruby.

I know that I could just copy out the script data to another file, or
eval it as a string, but there are potential problems with that:
specifically, the fact that I'm trying to distribute binary files
along with my Ruby program, which will be added to the __END__ section
of the Ruby script before it is appended to the wrapper binary. Since
these files will be quite large (50-150MB), I want to avoid copying
them to another file, or loading them fully into RAM, if at all
possible.

Any ideas would be greatly appreciated. I can post code snippets first
thing tomorrow morning once I'm back at work; I just wanted to see if
anyone had any quick suggestions before that.

-- 
Lennon
rcoder.net