|ATEXIT(3)||Library Functions Manual||ATEXIT(3)|
atexit — register
a function to be called on exit
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
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.
atexit function 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
Setting errno on error and the behavior when a shared object is unloaded are extensions to that standard.
|June 27, 2019||OpenBSD-current|