1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Chris Torek. 7 * 8 * %sccs.include.redist.c% 9 */ 10 11 #if defined(LIBC_SCCS) && !defined(lint) 12 static char sccsid[] = "@(#)atexit.c 5.1 (Berkeley) 05/15/90"; 13 #endif /* LIBC_SCCS and not lint */ 14 15 #include <stddef.h> 16 #include <stdlib.h> 17 #include "atexit.h" 18 19 /* 20 * Register a function to be performed at exit. 21 */ 22 int 23 atexit(fn) 24 void (*fn)(); 25 { 26 static struct atexit __atexit0; /* one guaranteed table */ 27 register struct atexit *p; 28 29 if ((p = __atexit) == NULL) 30 __atexit = p = &__atexit0; 31 if (p->ind >= ATEXIT_SIZE) { 32 if ((p = malloc(sizeof(*p))) == NULL) 33 return (-1); 34 __atexit->next = p; 35 __atexit = p; 36 } 37 p->fns[p->ind++] = fn; 38 return (0); 39 } 40