register a function to be called on exit
() function registers the given
to be called at program exit,
whether via exit(3)
via return from the program's main
so registered are called in reverse order; no arguments are passed. At least
32 functions can always be registered, and more are allowed as long as
sufficient memory can be allocated.
If a shared object is unloaded from process memory using
any functions registered by calling atexit
that shared object will be called in reverse order and unregistered. Note that
it is the source of the call to atexit
matters, not the source of the function that was registered.
() is very difficult to use correctly without
races. Unless absolutely necessary, please avoid using it.
() function returns the value 0 if
successful; otherwise the value -1 is returned and the global variable
is set to indicate the error.
- No memory was available to add the function to the list.
The existing list of functions is unmodified.
() function conforms to
The behavior when a shared object is unloaded is an extension to that