grantpt, unlockpt, and ptsname

I’m having trouble compiling dbvi, an open source console-based front-end to
gdb, on QNX 6.2. The function prototypes are in stdlib.h, but at link time
I get “undefined reference to grantpt”, repeated for unlockpt and ptsname.
I can’t imagine that I need to link a library for something that’s defined
in stdlib.h, but that looks like what’s happening. I haven’t the foggiest
idea what that library might be, however. Anyone have any ideas?

James Ingraham
Sage Automation, Inc.