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(5) 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(5)

SunOS 5.11							    25 May 2001 							atexit(3C)