For general applications that wish to use the services provided by Linux-PAM the following is a summary of the relevant linking information:
#include <security/pam_appl.h>
cc -o application .... -lpam
In addition to libpam, there is a library of miscellaneous functions that make the job of writing PAM-aware applications easier (this library is not covered in the DCE-RFC for PAM and is specific to the Linux-PAM distribution):
#include <security/pam_appl.h>
#include <security/pam_misc.h>
cc -o application .... -lpam -lpam_misc