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
Functions 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
() from that shared object will be
called in reverse order and unregistered. Note that it is the source of the
() that matters, not the
source of the function that was registered.
() is very difficult to use correctly
Unless absolutely necessary, please avoid using it.
() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno
is set to indicate
- 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