| ATEXIT(3) | Library Functions Manual | ATEXIT(3) |
atexit — register
a function to be called on exit
#include
<stdlib.h>
int
atexit(void
(*function)(void));
The
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.
The atexit() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno is set to indicate the
error.
ENOMEM]The atexit() function conforms to
ANSI X3.159-1989
(“ANSI C89”).
The behavior when a shared object is unloaded is an extension to that standard.
| May 12, 2015 | OpenBSD-6.1 |