NAME
       im_mmapinrw  -  memory  maps  a  VASARI image file  with read and write
       access
SYNOPSIS
       #include <vips/vips.h>
       IMAGE *im_mmapinrw(file_name)
       char *file_name;
DESCRIPTION
       im_mmapinrw(3) works exactly as im_mmapin but the entered file_name  is
       memory mapped with read and write permissions.  This is useful for some
       applications, like writing lines onto an existing file.  Since the user
       might  change accidentally the context of the original file, great care
       should taken when handling a file with this routine.
       im_open(3) is generally more convenient.
RETURN VALUE
       The function returns the image descriptor on success and NULL on error.
SEE ALSO
       im_close(3), im_open(3), im_makerw(3).
COPYRIGHT
       N. Dessipris
AUTHOR
       N. Dessipris - 11/04/1990
                                 22 April 1991