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1.1 ! root 1: /* ! 2: * Copyright (c) 1988, 1989, 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: * Adam de Boor. ! 7: * ! 8: * Redistribution and use in source and binary forms are permitted ! 9: * provided that: (1) source distributions retain this entire copyright ! 10: * notice and comment, and (2) distributions including binaries display ! 11: * the following acknowledgement: ``This product includes software ! 12: * developed by the University of California, Berkeley and its contributors'' ! 13: * in the documentation or other materials provided with the distribution ! 14: * and in all advertising materials mentioning features or use of this ! 15: * software. Neither the name of the University nor the names of its ! 16: * contributors may be used to endorse or promote products derived ! 17: * from this software without specific prior written permission. ! 18: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR ! 19: * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED ! 20: * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. ! 21: */ ! 22: ! 23: #ifndef lint ! 24: static char sccsid[] = "@(#)lstFirst.c 5.3 (Berkeley) 6/1/90"; ! 25: #endif /* not lint */ ! 26: ! 27: /*- ! 28: * LstFirst.c -- ! 29: * Return the first node of a list ! 30: */ ! 31: ! 32: #include "lstInt.h" ! 33: ! 34: /*- ! 35: *----------------------------------------------------------------------- ! 36: * Lst_First -- ! 37: * Return the first node on the given list. ! 38: * ! 39: * Results: ! 40: * The first node or NILLNODE if the list is empty. ! 41: * ! 42: * Side Effects: ! 43: * None. ! 44: * ! 45: *----------------------------------------------------------------------- ! 46: */ ! 47: LstNode ! 48: Lst_First (l) ! 49: Lst l; ! 50: { ! 51: if (!LstValid (l) || LstIsEmpty (l)) { ! 52: return (NILLNODE); ! 53: } else { ! 54: return ((LstNode)((List)l)->firstPtr); ! 55: } ! 56: } ! 57:
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