4.3BSD-Reno/src/lib/libc/string/strcspn.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * 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 defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strcspn.c	5.5 (Berkeley) 5/16/90";
#endif /* LIBC_SCCS and not lint */

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

/*
 * Span the complement of string s2.
 */
size_t
strcspn(s1, s2)
	const char *s1;
	register const char *s2;
{
	register const char *p, *spanp;
	register char c, sc;

	/*
	 * Stop as soon as we find any character from s2.  Note that there
	 * must be a NUL in s2; it suffices to stop when we find that, too.
	 */
	for (p = s1;;) {
		c = *p++;
		spanp = s2;
		do {
			if ((sc = *spanp++) == c)
				return (p - 1 - s1);
		} while (sc != 0);
	}
	/* NOTREACHED */
}