There are several lines in the code which cause GCC to warn the user
about undefined behaviour. Most of these are potential buffer overflow
problems. Which come from either overwriting a buffer which may be too
small for a given input, or writing to, or from, a string not guaranteed
to be null-terminated, such as any of the char[] fields in a utmp
struct. Almost all come from an improper usage of strcmp or strncmp or
similar.
The README file mentions the wrong pathnames in its installation,
instructing the user to install the binary in "/usr/etc", rather than
the "/usr/sbin" directory, for example. It also has a typo at the very
end. These errors have been fixed.
The Makefile for the project was unable to properly build. It didn't
call an X11 library which was needed for the program to link, but called
various libraries which weren't necessary. It also didn't install the
/etc/timeouts config file, didn't have an uninstall option, and it's
install would fail, due to the fact that it used non-existent
directories as install destinations, and broken user and group settings
for the files.
All of the afformentioned problems have been mended in this commit. It's
likely that all of the problems which actually broke the program were
due to a difference in Unix systems of the early 90s compared to 2020.
It's likely the X11 libraries were reorganised, and the users and groups
in the install command have been obsoleted.
