last_registered_file
if ((obuf = last_registered_file(0)) == NULL)
FILE * last_registered_file(int);
last_file = last_registered_file(0);
mip->mi_head_end = last_registered_file(0);
mip->mi_head_end = last_registered_file(0);
fp = last_registered_file(0); /* get last registered file or pipe */
mip->mi_pipe_end = last_registered_file(0); /* for mime_decode_close() */
if ((obuf = last_registered_file(0)) == NULL)
end_of_prefix = last_registered_file(0);