|ATEXIT(3)||Library Functions Manual||ATEXIT(3)|
atexit() function registers the given function to be called at program exit, whether via exit(3) or via return from the program's
main(). 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
dlclose(3), then any functions
registered by calling
atexit() from that shared
object will be called in reverse order and unregistered. Note that it is the
source of the call to
atexit() that matters, not the
source of the function that was registered.
atexit() is very difficult to use
correctly without creating exit(3)-time
races. Unless absolutely necessary, please avoid using it.
atexitfunction returns the value 0 if successful; otherwise a non-zero value is returned and the global variable errno is set to indicate the error.
atexit() function conforms to ANSI X3.159-1989 (“ANSI C89”).
Setting errno on error and the behavior when a shared object is unloaded are extensions to that standard.
|June 27, 2019||OpenBSD-current|