Hello Jan,

do you need to read the data from the file descriptor in a Scheme
program?  If so, I guess you can make a wrapper procedure [1] that uses
'scm_fdes_to_port' from 'libguile.h' to convert your file descriptor to
a SCM port and return the port into the Scheme world.

Here's the description of 'scm_fdes_to_port' from GNU Guile 2.0.9
sources:

--8<---------------cut here---------------start------------->8---
/* Build a Scheme port from an open file descriptor `fdes'.
   MODE indicates whether FILE is open for reading or writing; it uses
      the same notation as open-file's second argument.
   NAME is a string to be used as the port's filename.
*/
SCM
scm_i_fdes_to_port (int fdes, long mode_bits, SCM name)
--8<---------------cut here---------------end--------------->8---

Hope this helps,

- Artyom

[1] See '(guile) C Extensions' chapter from the Guile manual.

-- 
Artyom V. Poptsov <poptsov.artyom@gmail.com>;  GPG Key: 0898A02F
Home page: http://poptsov-artyom.narod.ru/