ATEXIT(3)		   Linux Programmers Manual		    ATEXIT(3)



NAME
       atexit - register a function to be called at normal process termination

SYNOPSIS
       #include 

       int atexit(void (*function)(void));

DESCRIPTION
       The atexit() function registers the given function to be called at nor
       mal process termination, either via exit(3) or via return from the pro
       grams main().  Functions so registered are called in the reverse order
       of their registration; no arguments are passed.

       POSIX.1-2001  requires that an implementation allow at least ATEXIT_MAX
       (32) such functions to be registered.  The actual limit supported by an
       implementation can be obtained using sysconf(3).

       When  a child process is created via fork(2), it inherits copies of its
       parents registrations.  Upon a successful call to one of  the  exec(3)
       functions, all registrations are removed.

RETURN VALUE
       The  atexit()  function returns the value 0 if successful; otherwise it
       returns a non-zero value.

CONFORMING TO
       SVr4, 4.3BSD, C89, C99, POSIX.1-2001.

NOTES
       Functions registered using atexit() (and on_exit(3)) are not called  if
       a process terminates abnormally because of the delivery of a signal.

   Linux Notes
       Since  glibc  2.2.3,  atexit()  (and  on_exit(3))  can be used within a
       shared library to establish functions that are called when  the	shared
       library is unloaded.

EXAMPLE
       #include 
       #include 
       #include 

       void
       bye(void)
       {
	   printf("That was all, folks\n");
       }

       int
       main(void)
       {
	   long a;
	   int i;

	   a = sysconf(_SC_ATEXIT_MAX);
	   printf("ATEXIT_MAX = %ld\n", a);

	   i = atexit(bye);
	   if (i != 0) {
	       fprintf(stderr, "cannot set exit function\n");
	       exit(EXIT_FAILURE);
	   }

	   exit(EXIT_SUCCESS);
       }

SEE ALSO
       _exit(2), exit(3), on_exit(3)

COLOPHON
       This  page  is  part of release 3.05 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



Linux				  2003-11-01			     ATEXIT(3)