Hi,

 Bauer, Christoph [Wednesday 14 September 2005] :
 > Bigarray.Genarray.map_file uses mmap to "read" a file. How can
 > I specify an offset in the file (like the offset parameter in mmap)?
 > Unix.lseek doesn't help me.

You can't: mmap is called with offset 0 (see
otherlibs/bigarray/mmap_unix.c). 

 > How can I do an munmap? I ask because of these lines from the man-page:
 > 
 >        The munmap system call deletes the mappings for the speci-
 >        fied address  range,  and  causes  further  references  to
 >        addresses within the range to generate invalid memory ref-
 >        erences.  The region is also automatically  unmapped  when
 >        the process is terminated.  On the other hand, closing the
 >        file descriptor does not unmap the region.

unmap() is called when the bigarray is collected by the GC.

-- 
   Olivier