xref: /freebsd/lib/libc/amd64/string/strsep.c (revision fd2ecd91aeeeab579c769c9a39f90b4bd4a493a9)
1*fd2ecd91SRobert Clausecker /*-
2*fd2ecd91SRobert Clausecker  * Copyright (c) 2023 The FreeBSD Foundation
3*fd2ecd91SRobert Clausecker  *
4*fd2ecd91SRobert Clausecker  * This software was developed by Robert Clausecker <fuz@FreeBSD.org>
5*fd2ecd91SRobert Clausecker  * under sponsorship from the FreeBSD Foundation.
6*fd2ecd91SRobert Clausecker  *
7*fd2ecd91SRobert Clausecker  * Redistribution and use in source and binary forms, with or without
8*fd2ecd91SRobert Clausecker  * modification, are permitted provided that the following conditions
9*fd2ecd91SRobert Clausecker  * are met:
10*fd2ecd91SRobert Clausecker  * 1. Redistributions of source code must retain the above copyright
11*fd2ecd91SRobert Clausecker  *    notice, this list of conditions and the following disclaimer.
12*fd2ecd91SRobert Clausecker  * 2. Redistributions in binary form must reproduce the above copyright
13*fd2ecd91SRobert Clausecker  *    notice, this list of conditions and the following disclaimer in the
14*fd2ecd91SRobert Clausecker  *    documentation and/or other materials provided with the distribution.
15*fd2ecd91SRobert Clausecker  *
16*fd2ecd91SRobert Clausecker  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ''AS IS'' AND
17*fd2ecd91SRobert Clausecker  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18*fd2ecd91SRobert Clausecker  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19*fd2ecd91SRobert Clausecker  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20*fd2ecd91SRobert Clausecker  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21*fd2ecd91SRobert Clausecker  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22*fd2ecd91SRobert Clausecker  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23*fd2ecd91SRobert Clausecker  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24*fd2ecd91SRobert Clausecker  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25*fd2ecd91SRobert Clausecker  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26*fd2ecd91SRobert Clausecker  * SUCH DAMAGE
27*fd2ecd91SRobert Clausecker  */
28*fd2ecd91SRobert Clausecker 
29*fd2ecd91SRobert Clausecker #include <sys/cdefs.h>
30*fd2ecd91SRobert Clausecker #include <string.h>
31*fd2ecd91SRobert Clausecker 
32*fd2ecd91SRobert Clausecker size_t __strcspn(const char *, const char *);
33*fd2ecd91SRobert Clausecker 
34*fd2ecd91SRobert Clausecker /*
35*fd2ecd91SRobert Clausecker  * We have a fast strcspn() on amd64.  Use it over a direct
36*fd2ecd91SRobert Clausecker  * implementation of strsep for better performance.
37*fd2ecd91SRobert Clausecker  */
38*fd2ecd91SRobert Clausecker char *
strsep(char ** stringp,const char * delim)39*fd2ecd91SRobert Clausecker strsep(char **stringp, const char *delim)
40*fd2ecd91SRobert Clausecker {
41*fd2ecd91SRobert Clausecker 	size_t n;
42*fd2ecd91SRobert Clausecker 	char *s;
43*fd2ecd91SRobert Clausecker 
44*fd2ecd91SRobert Clausecker 	s = *stringp;
45*fd2ecd91SRobert Clausecker 	if (s == NULL)
46*fd2ecd91SRobert Clausecker 		return (NULL);
47*fd2ecd91SRobert Clausecker 
48*fd2ecd91SRobert Clausecker 	n = __strcspn(s, delim);
49*fd2ecd91SRobert Clausecker 	if (s[n] == '\0')
50*fd2ecd91SRobert Clausecker 		*stringp = NULL;
51*fd2ecd91SRobert Clausecker 	else {
52*fd2ecd91SRobert Clausecker 		s[n] = '\0';
53*fd2ecd91SRobert Clausecker 		*stringp = s + n + 1;
54*fd2ecd91SRobert Clausecker 	}
55*fd2ecd91SRobert Clausecker 
56*fd2ecd91SRobert Clausecker 	return (s);
57*fd2ecd91SRobert Clausecker }
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