curs_memleaks(3X) Library calls curs_memleaks(3X)

exit_curses, exit_terminfo - check for memory leaks in curses

#include <ncurses/curses.h>
void exit_curses(int code);
#include <term.h>
void exit_terminfo(int code);
/* deprecated (intentionally not declared in curses.h or term.h) */
void _nc_freeall(void);
void _nc_free_and_exit(int code);
void _nc_free_tinfo(int code);

These functions are used to simplify analysis of memory leaks in the ncurses library.

Any implementation of curses must not free the memory associated with a screen, since (even after calling endwin(3X)), 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.

Some of the functions are named with a “_nc_” prefix because they are not intended for use in the non-debugging library:

_nc_freeall
This frees (almost) all of the memory allocated by ncurses.
_nc_free_and_exit
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.
_nc_free_tinfo
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.

The functions prefixed “_nc” 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.

The exit_curses and exit_terminfo functions call _nc_free_and_exit and _nc_free_tinfo if the library is configured to support memory-leak checking. If the library is not configured to support memory-leak checking, they simply call exit.

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.

In any implementation of X/Open Curses, an application can free part of the memory allocated by curses:

The portable part of exit_curses can be freed using delscreen, passing the SCREEN pointer returned by newterm.
In some implementations, there is a global variable sp which could be used, e.g., if the screen were only initialized using initscr.
The portable part of exit_terminfo can be freed using del_curterm.
In this case, there is a global variable cur_term which can be used as parameter.

curses(3X), curs_initscr(3X), curs_terminfo(3X)

2024-03-16 ncurses 6.5