Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

 ◄Summary► ◄Example►                         ◄Up► ◄Contents► ◄Index► ◄Back►
────────────────────────────────────────────────────────────────────────────
 
     The atexit and onexit functions are passed the address of a
     function (<func>) to be called when the program terminates
     normally. Successive calls to these functions create a register
     of functions that are executed "last in, first out." No more than
     32 functions can be registered; a NULL is returned if the number
     of functions exceeds 32. The functions passed cannot take
     parameters.
 
     The atexit function conforms to the ANSI standard and should be
     used instead of onexit where ANSI portability is desired.
 
     In the OS/2 environment, the atexit function calls the OS/2
     function DosExitList. Also, all routines passed to atexit or
     onexit should have the _loadds attribute if used in multithread
     dynamic-link libraries.
 
     Return Value
 
     The atexit function returns 0 if successful, or a nonzero value if
     an error occurs (e.g., if there are already 32 exit functions
     defined).
 
     The onexit function returns a pointer to the function if
     successful, and returns NULL if there is no space left to store
     the function pointer.
                                    -♦-