[erlang-questions] port_driver.c problems

[elmer_fwd@REDACTED]

The code for port_driver.c does an:

#include "port_driver.h"

When I compile the example code with the command:

gcc -o exmpledrv -shared complex.c port_driver.c

At the link phase, I get the errors:

/cygdrive/c/DOCUME~1/s360852/LOCALS~1/Temp/ccXxTBKu.o:port_driver.c:(.text+0xe):
undefined reference to `_driver_alloc'
/cygdrive/c/DOCUME~1/s360852/LOCALS~1/Temp/ccXxTBKu.o:port_driver.c:(.text+0x2f):
undefined reference to `_driver_free'
/cygdrive/c/DOCUME~1/s360852/LOCALS~1/Temp/ccXxTBKu.o:port_driver.c:(.text+0x98):
undefined reference to `_driver_output'

This implies to me that the functions driver_alloc,
driver_free and driver_output are not available for linking.

Anybody have a suggestion?

thanks