curs_memleaks.3x man page
_nc_freeall, _nc_free_and_exit, _nc_free_tinfo — curses memory-leak checking
These functions are used to simplify analysis of memory leaks in the ncurses library. They are normally not available; they must be configured into the library at build time using the --disable-leaks option. That compiles-in code that frees memory that normally would not be freed.
Any implementation of curses must not free the memory associated with a screen, since (even after calling endwin), it must be available for use in the next call to refresh(3X). There are also chunks of memory held for performance reasons. That makes it hard to analyze curses applications for memory leaks. When using the specially configured debugging version of the ncurses library, applications can call functions which free those chunks of memory, simplifying the process of memory-leak checking.
These functions are named with a “_nc_” prefix because they are not intended for use in the non-debugging library:
This frees (almost) all of the memory allocated by ncurses.
This frees the memory allocated by ncurses (like _nc_freeall), and exits the program. It is preferred over _nc_freeall since some of that memory may be required to keep the application running. Simply exiting (with the given exit-code) is safer.
Use this function if only the low-level terminfo functions (and corresponding library) are used. Like _nc_free_and_exit, it exits the program after freeing memory.
These functions do not return a value.
These functions are not part of X/Open Curses; nor do other implementations of curses provide a similar feature.