strspn.c

早期freebsd实现

/*  $Revision: 1.2 $
**
**  This file has been modified to get it to compile more easily
**  on pre-4.4BSD systems.  Rich $alz, June 1991.
*/
#define const /* NULL */
#define size_t int
#define NULL 0

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that: (1) source distributions retain this entire copyright
 * notice and comment, and (2) distributions including binaries display
 * the following acknowledgement:  ``This product includes software
 * developed by the University of California, Berkeley and its contributors''
 * in the documentation or other materials provided with the distribution
 * and in all advertising materials mentioning features or use of this
 * software. Neither the name of the University nor the names of its
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if 0
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strspn.c	5.7 (Berkeley) 6/1/90";
#endif /* LIBC_SCCS and not lint */

#include <sys/stdc.h>
#include <string.h>
#endif

/*
 * Span the string s2 (skip characters that are in s2).
 */
size_t
strspn(s1, s2)
	const char *s1;
	register const char *s2;
{
	register const char *p = s1, *spanp;
	register char c, sc;

	/*
	 * Skip any characters in s2, excluding the terminating \0.
	 */
cont:
	c = *p++;
	for (spanp = s2; (sc = *spanp++) != 0;)
		if (sc == c)
			goto cont;
	return (p - 1 - s1);
}