ATEXIT(3C) Standard C Library Functions ATEXIT(3C)
NAME
atexit - register a function to run at process termination or object
unloading
SYNOPSIS
#include <stdlib.h>
int atexit(
void (*func)(void));
DESCRIPTION
The
atexit() function registers the function pointed to by
func to be
called without arguments on normal termination of the program or when
the object defining the function is unloaded.
Normal termination occurs by either a call to the
exit(3C) function
or a return from
main(). Object unloading occurs when a call to
dlclose(3C) results in the object becoming unreferenced.
The number of functions that may be registered with
atexit() is
limited only by available memory (refer to the
_SC_ATEXIT_MAX argument of
sysconf(3C)).
After a successful call to any of the
exec(2) functions, any
functions previously registered by
atexit() are no longer registered.
On process exit, functions are called in the reverse order of their
registration. On object unloading, any functions belonging to an
unloadable object are called in the reverse order of their
registration.
RETURN VALUES
Upon successful completion, the
atexit() function returns 0.
Otherwise, it returns a non-zero value.
ERRORS
The
atexit() function may fail if:
ENOMEM Insufficient storage space is available.
USAGE
The functions registered by a call to
atexit() must return to ensure
that all registered functions are called.
There is no way for an application to tell how many functions have
already been registered with
atexit().
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | Safe |
+--------------------+-----------------+
SEE ALSO
exec(2),
dlclose(3C),
exit(3C),
sysconf(3C),
attributes(7) May 25, 2001 ATEXIT(3C)
