I've tried posting on help-gnu-emacs mailing list first, but not luck so far, so I thought I'd try here, as I know there are many savvy emacs users around.

I have a small Ruby CLI program that I want to call from emacs. This script simply opens an emacs orgmode file from a specific location in my hard drive, and does some text processing. When I call it from the terminal directly, it works fine. When I call it from emacs, the script fails with an encoding error.

(defun test ()
(let ((universal-coding-system-argument 'utf-8-unix))
(shell-command "/Users/myself/.rvm/bin/rvm ruby-1.9.3-p194 do /usr/bin/myrubyscript")
))
(add-hook 'after-save-hook 'test)

NOTE: The (let ((universal-coding-system-argument 'utf-8-unix)) was an attempt to fix it, but it made no difference whatsoever.

After I save a buffer, the shell-command function is fired, but I get the following output in the "*Shell Command Output*" buffer:

F, [2012-08-30T01:59:18.688827 #94004] FATAL -- : invalid byte sequence in US-ASCII (ArgumentError)
/Users/myself/.rvm/gems/ruby-1.9.3-p194/gems/org-ruby-0.6.3/lib/org-ruby/parser.rb:89:in `split'
/Users/myself/.rvm/gems/ruby-1.9.3-p194/gems/org-ruby-0.6.3/lib/org-ruby/parser.rb:89:in `initia

The strange thing is that the file that this script opens *is* accessible, and is the same file it would open if it were fired up from the terminal. For some reason, Emacs is getting in the way, but I have no idea what that could be. Am I missing something? If someone could enlighten me here, I'd be really grateful!