National Instruments 320682C - page 30

ANSI C Library Chapter 1
LabWindows/CVI Standard Libraries 1-10 © National Instruments Corporation
Parameter Discussion
mode is the same as the mode parameter to fopen.
You should use a mode value that is consistent with the mode in which you originally opened the
file. If you use write capabilities that were not enabled when the file handle was originally
opened, the call to fdopen succeeds, but any attempt to write fails. For instance, if you
originally opened the file for reading only, you can pass "rw" to fdopen, but any call to
fwrite fails.