WCSTRING(3C) Standard C Library Functions WCSTRING(3C)


NAME


wcstring, wcscat, wscat, wcsncat, wsncat, wcscmp, wscmp, wcsncmp, wsncmp,
wcscpy, wscpy, wcsncpy, wsncpy, wslen, wcschr, wschr, wcsrchr, wsrchr,
windex, wrindex, wcspbrk, wspbrk, wcswcs, wcsspn, wsspn, wcscspn, wscspn,
wcstok, wstok - wide-character string operations

SYNOPSIS


#include <wchar.h>

wchar_t *wcscat(wchar_t *ws1, const wchar_t *ws2);


wchar_t *wcsncat(wchar_t *restrict ws1, const wchar_t *restrict ws2,
size_t n);


int wcscmp(const wchar_t *ws1, const wchar_t *ws2);


int wcsncmp(const wchar_t *ws1, const wchar_t *ws2, size_t n);


wchar_t *wcscpy(wchar_t *ws1, const wchar_t *ws2);


wchar_t *wcsncpy(wchar_t *restrict ws1, const wchar_t *restrict ws2,
size_t n);


wchar_t *wcschr(const wchar_t *ws, wchar_t wc);


wchar_t *wcsrchr(const wchar_t *ws, wchar_t wc);


wchar_t *wcspbrk(const wchar_t *ws1, const wchar_t *ws2);


wchar_t *wcswcs(const wchar_t *ws1, const wchar_t *ws2);


size_t wcsspn(const wchar_t *ws1, const wchar_t *ws2);


size_t wcscspn(const wchar_t *ws1, const wchar_t *ws2);


XPG4, SUS, SUSv2, SUSv3
wchar_t *wcstok(wchar_t *restrict ws1, const wchar_t *restrict ws2);


Default and other standards


wchar_t *wcstok(wchar_t *ws1, const wchar_t *ws2, wchar_t **ptr);


#include <widec.h>

wchar_t *wscat(wchar_t *ws1, const wchar_t *ws2);


wchar_t *wsncat(wchar_t *ws1, const wchar_t *ws2, size_t n);


int wscmp(const wchar_t *ws1, const wchar_t *ws2);


int wsncmp(const wchar_t *ws1, const wchar_t *ws2, size_t n);


wchar_t *wscpy(wchar_t *ws1, const wchar_t *ws2);


wchar_t *wsncpy(wchar_t *ws1, const wchar_t *ws2, size_t n);


size_t wslen(const wchar_t *ws);


wchar_t *wschr(const wchar_t *ws, wchat_t wc);


wchar_t *wsrchr(const wchar_t *ws, wchat_t wc);


wchar_t *wspbrk(const wchar_t *ws1, const wchar_t *ws2);


size_t wsspn(const wchar_t *ws1, const wchar_t *ws2);


size_t wscspn(const wchar_t *ws1, const wchar_t *ws2);


wchar_t *wstok(wchar_t *ws1, const wchar_t *ws2);


wchar_t *windex(const wchar_t *ws, wchar_t wc);


wchar_t *wrindex(const wchar_t *ws, wchar_t wc);


ISO C++
#include <wchar.h>

const wchar_t *wcschr(const wchar_t *ws, wchar_t wc);


const wchar_t *wcspbrk(const wchar_t *ws1, const wchar_t *ws2);


const wchar_t *wcsrchr(const wchar_t *ws, wchar_t wc);


#include <cwchar>

wchar_t *std::wcschr(wchar_t *ws, wchar_t wc);


wchar_t *std::wcspbrk(wchar_t *ws1, const wchar_t *ws2);


wchar_t *std::wcsrchr(wchar_t *ws, wchar_t wc);


DESCRIPTION


These functions operate on wide-character strings terminated by wchar_t
NULL characters. During appending or copying, these routines do not check
for an overflow condition of the receiving string. In the following, ws,
ws1, and ws2 point to wide-character strings terminated by a wchar_t
NULL.

wcscat(), wscat()
The wcscat() and wscat() functions append a copy of the wide-character
string pointed to by ws2 (including the terminating null wide-character
code) to the end of the wide-character string pointed to by ws1. The
initial wide-character code of ws2 overwrites the null wide-character
code at the end of ws1. If copying takes place between objects that
overlap, the behavior is undefined. Both functions return s1; no return
value is reserved to indicate an error.

wcsncat(), wsncat()
The wcsncat() and wsncat() functions append not more than n wide-
character codes (a null wide-character code and wide-character codes that
follow it are not appended) from the array pointed to by ws2 to the end
of the wide-character string pointed to by ws1. The initial wide-
character code of ws2 overwrites the null wide-character code at the end
of ws1. A terminating null wide-character code is always appended to the
result. Both functions return ws1; no return value is reserved to
indicate an error.

wcscmp(), wscmp()
The wcscmp() and wscmp() functions compare the wide-character string
pointed to by ws1 to the wide-character string pointed to by ws2. The
sign of a non-zero return value is determined by the sign of the
difference between the values of the first pair of wide-character codes
that differ in the objects being compared. Upon completion, both
functions return an integer greater than, equal to, or less than zero, if
the wide-character string pointed to by ws1 is greater than, equal to, or
less than the wide-character string pointed to by ws2.

wcsncmp(), wsncmp()
The wcsncmp() and wsncmp() functions compare not more than n wide-
character codes (wide-character codes that follow a null wide character
code are not compared) from the array pointed to by ws1 to the array
pointed to by ws2. The sign of a non-zero return value is determined by
the sign of the difference between the values of the first pair of wide-
character codes that differ in the objects being compared. Upon
successful completion, both functions return an integer greater than,
equal to, or less than zero, if the possibly null-terminated array
pointed to by ws1 is greater than, equal to, or less than the possibly
null-terminated array pointed to by ws2.

wcscpy(), wscpy()
The wcscpy() and wscpy() functions copy the wide-character string pointed
to by ws2 (including the terminating null wide-character code) into the
array pointed to by ws1. If copying takes place between objects that
overlap, the behavior is undefined. Both functions return ws1; no return
value is reserved to indicate an error.

wcsncpy(), wsncpy()
The wcsncpy() and wsncpy() functions copy not more than n wide-character
codes (wide-character codes that follow a null wide character code are
not copied) from the array pointed to by ws2 to the array pointed to by
ws1. If copying takes place between objects that overlap, the behavior is
undefined. If the array pointed to by ws2 is a wide-character string that
is shorter than n wide-character codes, null wide-character codes are
appended to the copy in the array pointed to by ws1, until a total n
wide-character codes are written. Both functions return ws1; no return
value is reserved to indicate an error.

wslen()
The wslen() function computes the number of wide-character codes in the
wide-character string to which ws points, not including the terminating
null wide-character code. It returns ws; no return value is reserved to
indicate an error.

wcschr(), wschr()
The wcschr() and wschr() functions locate the first occurrence of wc in
the wide-character string pointed to by ws. The value of wc must be a
character representable as a type wchar_t and must be a wide-character
code corresponding to a valid character in the current locale. The
terminating null wide-character code is considered to be part of the
wide-character string. Upon completion, both functions return a pointer
to the wide-character code, or a null pointer if the wide-character code
is not found.

wcsrchr(), wsrchr()
The wcsrchr() and wsrchr() functions locate the last occurrence of wc in
the wide-character string pointed to by ws. The value of wc must be a
character representable as a type wchar_t and must be a wide-character
code corresponding to a valid character in the current locale. The
terminating null wide-character code is considered to be part of the
wide-character string. Upon successful completion, both functions return
a pointer to the wide-character code, or a null pointer if wc does not
occur in the wide-character string.

windex(), wrindex()
The windex() and wrindex() functions behave the same as wschr() and
wsrchr(), respectively.

wcspbrk(), wspbrk()
The wcspbrk() and wspbrk() functions locate the first occurrence in the
wide character string pointed to by ws1 of any wide-character code from
the wide-character string pointed to by ws2. Upon successful completion,
the function returns a pointer to the wide-character code, or a null
pointer if no wide-character code from ws2 occurs in ws1.

wcswcs()
The wcswcs() function locates the first occurrence in the wide-character
string pointed to by ws1 of the sequence of wide-character codes
(excluding the terminating null wide-character code) in the wide-
character string pointed to by ws2. Upon successful completion, the
function returns a pointer to the located wide-character string, or a
null pointer if the wide-character string is not found. If ws2 points to
a wide-character string with zero length, the function returns ws1.

wcsspn(), wsspn()
The wcsspn() and wsspn() functions compute the length of the maximum
initial segment of the wide-character string pointed to by ws1 which
consists entirely of wide-character codes from the wide-character string
pointed to by ws2. Both functions return the length ws1; no return value
is reserved to indicate an error.

wcscspn(), wscspn()
The wcscspn() and wscspn() functions compute the length of the maximum
initial segment of the wide-character string pointed to by ws1 which
consists entirely of wide-character codes not from the wide-character
string pointed to by ws2. Both functions return the length of the initial
substring of ws1; no return value is reserved to indicate an error.

wcstok(), wstok()
A sequence of calls to the wcstok() and wstok() functions break the wide-
character string pointed to by ws1 into a sequence of tokens, each of
which is delimited by a wide-character code from the wide-character
string pointed to by ws2.

Default and other standards


The third argument points to a caller-provided wchar_t pointer into which
the wcstok() function stores information necessary for it to continue
scanning the same wide-character string. This argument is not available
with the XPG4 and SUS versions of wcstok(), nor is it available with the
wstok() function. See standards(5).

The first call in the sequence has ws1 as its first argument, and is
followed by calls with a null pointer as their first argument. The
separator string pointed to by ws2 may be different from call to call.

The first call in the sequence searches the wide-character string pointed
to by ws1 for the first wide-character code that is not contained in the
current separator string pointed to by ws2. If no such wide-character
code is found, then there are no tokens in the wide-character string
pointed to by ws1, and wcstok() and wstok() return a null pointer. If
such a wide-character code is found, it is the start of the first token.

The wcstok() and wstok() functions then search from that point for a
wide-character code that is contained in the current separator string.
If no such wide-character code is found, the current token extends to the
end of the wide-character string pointed to by ws1, and subsequent
searches for a token will return a null pointer. If such a wide-character
code is found, it is overwritten by a null wide character, which
terminates the current token. The wcstok() and wstok() functions save a
pointer to the following wide-character code, from which the next search
for a token will start.

Each subsequent call, with a null pointer as the value of the first
argument, starts searching from the saved pointer and behaves as
described above.

Upon successful completion, both functions return a pointer to the first
wide-character code of a token. Otherwise, if there is no token, a null
pointer is returned.

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|CSI | Enabled |
+--------------------+-----------------+
|Interface Stability | See NOTES. |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO


malloc(3C), string(3C), wcscasecmp(3C), wcsdup(3C), wcslen(3C),
wcswidth(3C), wcwidth(3C), attributes(5), standards(5)

NOTES


The wcscat(), wcsncat(), wcscmp(), wcsncmp(), wcscpy(), wcsncpy(),
wcschr(), wcsrchr(), wcspbrk(), wcswcs(), wcsspn(), wcscspn(), and
wcstok() functions are Standard. The wscat(), wsncat(), wscmp(),
wsncmp(), wscpy(), wsncpy(), wslen(), wschr(), wsrchr(), wspbrk(),
wsspn(), wstok(), windex(), and wrindex() functions are Stable.


August 15, 2014 WCSTRING(3C)