I try to migrate an application from oracle 7 to 8.1.7

When I try to recompile my pro*c files, I get the following errors :
"undefined reference to `sqlcxt'",
"undefined reference to `sqlcx2t'",
"undefined reference to `sqliem'".

I have checked the includes of sqlca.h in my files, it seems OK.

I use the makefile demo_proc.mk like that :
make -f demo_proc.mk my_file

Is it correct ?

Thanks a lot...