Cygwin: mmap: allow remapping part of an existing anonymous mapping
[newlib-cygwin.git] / newlib / libc / string / wcstok.c
blobf7d1c5ee9c20a2edb98a5e88f367e0f3dfab9276
1 /*
2 FUNCTION
3 <<wcstok>>---get next token from a string
5 INDEX
6 wcstok
9 SYNOPSIS
10 #include <wchar.h>
11 wchar_t *wcstok(wchar_t *__restrict <[source]>,
12 const wchar_t *__restrict <[delimiters]>,
13 wchar_t **__restrict <[lasts]>);
15 DESCRIPTION
16 The <<wcstok>> function is the wide-character equivalent of the
17 <<strtok_r>> function (which in turn is the same as the <<strtok>>
18 function with an added argument to make it thread-safe).
20 The <<wcstok>> function is used to isolate (one at a time)
21 sequential tokens in a null-terminated wide-character string,
22 <<*<[source]>>>. A token is defined as a substring not containing
23 any wide-characters from <<*<[delimiters]>>>.
25 The first time that <<wcstok>> is called, <<*<[source]>>> should
26 be specified with the wide-character string to be searched, and
27 <<*<[lasts]>>>--but not <<lasts>>, which must be non-NULL--may be
28 random; subsequent calls, wishing to obtain further tokens from
29 the same string, should pass a null pointer for <<*<[source]>>>
30 instead but must supply <<*<[lasts]>>> unchanged from the last
31 call. The separator wide-character string, <<*<[delimiters]>>>,
32 must be supplied each time and may change between calls.
33 A pointer to placeholder <<*<[lasts]>>> must be supplied by
34 the caller, and is set each time as needed to save the state
35 by <<wcstok>>. Every call to <<wcstok>> with <<*<[source]>>>
36 == <<NULL>> must pass the value of <<*<[lasts]>>> as last set
37 by <<wcstok>>.
39 The <<wcstok>> function returns a pointer to the beginning of each
40 subsequent token in the string, after replacing the separator
41 wide-character itself with a null wide-character. When no more tokens
42 remain, a null pointer is returned.
44 RETURNS
45 <<wcstok>> returns a pointer to the first wide character of a token, or
46 <<NULL>> if there is no token.
48 NOTES
49 <<wcstok>> is thread-safe (unlike <<strtok>>, but like <<strtok_r>>).
50 <<wcstok>> writes into the string being searched.
52 PORTABILITY
53 <<wcstok>> is C99 and POSIX.1-2001.
55 <<wcstok>> requires no supporting OS subroutines.
57 QUICKREF
58 strtok ansi pure
60 /* wcstok for Newlib created by adapting strtok_r, 2008. */
62 * Copyright (c) 1988 Regents of the University of California.
63 * All rights reserved.
65 * Redistribution and use in source and binary forms, with or without
66 * modification, are permitted provided that the following conditions
67 * are met:
68 * 1. Redistributions of source code must retain the above copyright
69 * notice, this list of conditions and the following disclaimer.
70 * 2. Redistributions in binary form must reproduce the above copyright
71 * notice, this list of conditions and the following disclaimer in the
72 * documentation and/or other materials provided with the distribution.
73 * 3. Neither the name of the University nor the names of its contributors
74 * may be used to endorse or promote products derived from this software
75 * without specific prior written permission.
77 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
78 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
79 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
80 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
81 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
82 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
83 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
84 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
85 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
86 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
87 * SUCH DAMAGE.
90 #include <wchar.h>
92 wchar_t *
93 wcstok (register wchar_t *__restrict s,
94 register const wchar_t *__restrict delim,
95 wchar_t **__restrict lasts)
97 register const wchar_t *spanp;
98 register int c, sc;
99 wchar_t *tok;
102 if (s == NULL && (s = *lasts) == NULL)
103 return (NULL);
106 * Skip (span) leading delimiters (s += wcsspn(s, delim), sort of).
108 cont:
109 c = *s++;
110 for (spanp = delim; (sc = *spanp++) != L'\0';) {
111 if (c == sc) goto cont;
114 if (c == L'\0') { /* no non-delimiter characters */
115 *lasts = NULL;
116 return (NULL);
118 tok = s - 1;
121 * Scan token (scan for delimiters: s += wcscspn(s, delim), sort of).
122 * Note that delim must have one NUL; we stop if we see that, too.
124 for (;;) {
125 c = *s++;
126 spanp = delim;
127 do {
128 if ((sc = *spanp++) == c) {
129 if (c == L'\0')
130 s = NULL;
131 else
132 s[-1] = L'\0';
133 *lasts = s;
134 return (tok);
136 } while (sc != L'\0');
138 /* NOTREACHED */
141 /* The remainder of this file can serve as a regression test. Compile
142 * with -D_REGRESSION_TEST. */
143 #if defined(_REGRESSION_TEST) /* [Test code: example from C99 standard */
144 #include <stdio.h>
145 #include <wchar.h>
147 /* example from C99 standard with minor additions to be a test */
149 main(void)
151 int errs=0;
152 static wchar_t str1[] = L"?a???b,,,#c";
153 static wchar_t str2[] = L"\t \t";
154 wchar_t *t, *ptr1, *ptr2;
156 t = wcstok(str1, L"?", &ptr1); // t points to the token L"a"
157 if(wcscmp(t,L"a")) errs++;
158 t = wcstok(NULL, L",", &ptr1); // t points to the token L"??b"
159 if(wcscmp(t,L"??b")) errs++;
160 t = wcstok(str2, L" \t", &ptr2); // t is a null pointer
161 if(t != NULL) errs++;
162 t = wcstok(NULL, L"#,", &ptr1); // t points to the token L"c"
163 if(wcscmp(t,L"c")) errs++;
164 t = wcstok(NULL, L"?", &ptr1); // t is a null pointer
165 if(t != NULL) errs++;
167 printf("wcstok() test ");
168 if(errs) printf("FAILED %d test cases", errs);
169 else printf("passed");
170 printf(".\n");
172 return(errs);
174 #endif /* defined(_REGRESSION_TEST) ] */