usr/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.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strcspn.c   5.5 (Berkeley) %G%";
#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 */
}