newlib-cygwin/newlib/libc/string/wcstok.c

183 lines
5.8 KiB
C

/*
FUNCTION
<<wcstok>>---get next token from a string
INDEX
wcstok
ANSI_SYNOPSIS
#include <wchar.h>
wchar_t *wcstok(wchar_t *__restrict <[source]>,
const wchar_t *__restrict <[delimiters]>,
wchar_t **__restrict <[lasts]>);
TRAD_SYNOPSIS
#include <wchar.h>
wchar_t *wcstok(<[source]>, <[delimiters]>, <[lasts]>);
wchar_t *__restrict <[source]>;
wchar_t *__restrict <[delimiters]>;
wchar_t **__restrict <[lasts]>;
DESCRIPTION
The <<wcstok>> function is the wide-character equivalent of the
<<strtok_r>> function (which in turn is the same as the <<strtok>>
function with an added argument to make it thread-safe).
The <<wcstok>> function is used to isolate (one at a time)
sequential tokens in a null-terminated wide-character string,
<<*<[source]>>>. A token is defined as a substring not containing
any wide-characters from <<*<[delimiters]>>>.
The first time that <<wcstok>> is called, <<*<[source]>>> should
be specified with the wide-character string to be searched, and
<<*<[lasts]>>>--but not <<lasts>>, which must be non-NULL--may be
random; subsequent calls, wishing to obtain further tokens from
the same string, should pass a null pointer for <<*<[source]>>>
instead but must supply <<*<[lasts]>>> unchanged from the last
call. The separator wide-character string, <<*<[delimiters]>>>,
must be supplied each time and may change between calls.
A pointer to placeholder <<*<[lasts]>>> must be supplied by
the caller, and is set each time as needed to save the state
by <<wcstok>>. Every call to <<wcstok>> with <<*<[source]>>>
== <<NULL>> must pass the value of <<*<[lasts]>>> as last set
by <<wcstok>>.
The <<wcstok>> function returns a pointer to the beginning of each
subsequent token in the string, after replacing the separator
wide-character itself with a null wide-character. When no more tokens
remain, a null pointer is returned.
RETURNS
<<wcstok>> returns a pointer to the first wide character of a token, or
<<NULL>> if there is no token.
NOTES
<<wcstok>> is thread-safe (unlike <<strtok>>, but like <<strtok_r>>).
<<wcstok>> writes into the string being searched.
PORTABILITY
<<wcstok>> is C99 and POSIX.1-2001.
<<wcstok>> requires no supporting OS subroutines.
QUICKREF
strtok ansi pure
*/
/* wcstok for Newlib created by adapting strtok_r, 2008. */
/*
* Copyright (c) 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <wchar.h>
wchar_t *
_DEFUN (wcstok, (s, delim, lasts),
register wchar_t *__restrict s _AND
register const wchar_t *__restrict delim _AND
wchar_t **__restrict lasts)
{
register const wchar_t *spanp;
register int c, sc;
wchar_t *tok;
if (s == NULL && (s = *lasts) == NULL)
return (NULL);
/*
* Skip (span) leading delimiters (s += wcsspn(s, delim), sort of).
*/
cont:
c = *s++;
for (spanp = delim; (sc = *spanp++) != L'\0';) {
if (c == sc) goto cont;
}
if (c == L'\0') { /* no non-delimiter characters */
*lasts = NULL;
return (NULL);
}
tok = s - 1;
/*
* Scan token (scan for delimiters: s += wcscspn(s, delim), sort of).
* Note that delim must have one NUL; we stop if we see that, too.
*/
for (;;) {
c = *s++;
spanp = delim;
do {
if ((sc = *spanp++) == c) {
if (c == L'\0')
s = NULL;
else
s[-1] = L'\0';
*lasts = s;
return (tok);
}
} while (sc != L'\0');
}
/* NOTREACHED */
}
/* The remainder of this file can serve as a regression test. Compile
* with -D_REGRESSION_TEST. */
#if defined(_REGRESSION_TEST) /* [Test code: example from C99 standard */
#include <stdio.h>
#include <wchar.h>
/* example from C99 standard with minor additions to be a test */
int
main(void)
{
int errs=0;
static wchar_t str1[] = L"?a???b,,,#c";
static wchar_t str2[] = L"\t \t";
wchar_t *t, *ptr1, *ptr2;
t = wcstok(str1, L"?", &ptr1); // t points to the token L"a"
if(wcscmp(t,L"a")) errs++;
t = wcstok(NULL, L",", &ptr1); // t points to the token L"??b"
if(wcscmp(t,L"??b")) errs++;
t = wcstok(str2, L" \t", &ptr2); // t is a null pointer
if(t != NULL) errs++;
t = wcstok(NULL, L"#,", &ptr1); // t points to the token L"c"
if(wcscmp(t,L"c")) errs++;
t = wcstok(NULL, L"?", &ptr1); // t is a null pointer
if(t != NULL) errs++;
printf("wcstok() test ");
if(errs) printf("FAILED %d test cases", errs);
else printf("passed");
printf(".\n");
return(errs);
}
#endif /* defined(_REGRESSION_TEST) ] */