* install needed packages (if not installed already):
  * make
  * C compiler (e.g. gcc or clang)
  * libc development headers (package libc6-dev on Debian, glibc-headers on Hat)
  * libcrypt development headers if not included in libc (package libcrypt-dev on Debian, libxcrypt-devel on Hat)
  * PAM development headers (package libpam-dev on Debian, pam-devel on Hat)
* make
* make install
