1*22028508SToomas Soome /*-
2*22028508SToomas Soome * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
3*22028508SToomas Soome * All rights reserved.
4*22028508SToomas Soome *
5*22028508SToomas Soome * Redistribution and use in source and binary forms, with or without
6*22028508SToomas Soome * modification, are permitted provided that the following conditions
7*22028508SToomas Soome * are met:
8*22028508SToomas Soome * 1. Redistributions of source code must retain the above copyright
9*22028508SToomas Soome * notice, this list of conditions and the following disclaimer.
10*22028508SToomas Soome * 2. Redistributions in binary form must reproduce the above copyright
11*22028508SToomas Soome * notice, this list of conditions and the following disclaimer in the
12*22028508SToomas Soome * documentation and/or other materials provided with the distribution.
13*22028508SToomas Soome *
14*22028508SToomas Soome * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*22028508SToomas Soome * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*22028508SToomas Soome * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*22028508SToomas Soome * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*22028508SToomas Soome * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*22028508SToomas Soome * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*22028508SToomas Soome * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*22028508SToomas Soome * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*22028508SToomas Soome * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*22028508SToomas Soome * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*22028508SToomas Soome * SUCH DAMAGE.
25*22028508SToomas Soome */
26*22028508SToomas Soome
27*22028508SToomas Soome #include <sys/cdefs.h>
28*22028508SToomas Soome __FBSDID("$FreeBSD$");
29*22028508SToomas Soome
30*22028508SToomas Soome #include <sys/types.h>
31*22028508SToomas Soome #include <limits.h>
32*22028508SToomas Soome #include <string.h>
33*22028508SToomas Soome
34*22028508SToomas Soome #define IDX(c) ((u_char)(c) / LONG_BIT)
35*22028508SToomas Soome #define BIT(c) ((u_long)1 << ((u_char)(c) % LONG_BIT))
36*22028508SToomas Soome
37*22028508SToomas Soome size_t
strspn(const char * s,const char * charset)38*22028508SToomas Soome strspn(const char *s, const char *charset)
39*22028508SToomas Soome {
40*22028508SToomas Soome /*
41*22028508SToomas Soome * NB: idx and bit are temporaries whose use causes gcc 3.4.2 to
42*22028508SToomas Soome * generate better code. Without them, gcc gets a little confused.
43*22028508SToomas Soome */
44*22028508SToomas Soome const char *s1;
45*22028508SToomas Soome u_long bit;
46*22028508SToomas Soome u_long tbl[(UCHAR_MAX + 1) / LONG_BIT];
47*22028508SToomas Soome int idx;
48*22028508SToomas Soome
49*22028508SToomas Soome if(*s == '\0')
50*22028508SToomas Soome return (0);
51*22028508SToomas Soome
52*22028508SToomas Soome #if LONG_BIT == 64 /* always better to unroll on 64-bit architectures */
53*22028508SToomas Soome tbl[3] = tbl[2] = tbl[1] = tbl[0] = 0;
54*22028508SToomas Soome #else
55*22028508SToomas Soome for (idx = 0; idx < sizeof(tbl) / sizeof(tbl[0]); idx++)
56*22028508SToomas Soome tbl[idx] = 0;
57*22028508SToomas Soome #endif
58*22028508SToomas Soome for (; *charset != '\0'; charset++) {
59*22028508SToomas Soome idx = IDX(*charset);
60*22028508SToomas Soome bit = BIT(*charset);
61*22028508SToomas Soome tbl[idx] |= bit;
62*22028508SToomas Soome }
63*22028508SToomas Soome
64*22028508SToomas Soome for(s1 = s; ; s1++) {
65*22028508SToomas Soome idx = IDX(*s1);
66*22028508SToomas Soome bit = BIT(*s1);
67*22028508SToomas Soome if ((tbl[idx] & bit) == 0)
68*22028508SToomas Soome break;
69*22028508SToomas Soome }
70*22028508SToomas Soome return (s1 - s);
71*22028508SToomas Soome }
72