1MBSTOWCS(3) Linux Programmer's Manual MBSTOWCS(3)
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6 mbstowcs - convert a multibyte string to a wide-character string
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9 #include <stdlib.h>
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11 size_t mbstowcs(wchar_t *dest, const char *src, size_t n);
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14 If dest is not a NULL pointer, the mbstowcs() function converts the
15 multibyte string src to a wide-character string starting at dest. At
16 most n wide characters are written to dest. The conversion starts in
17 the initial state. The conversion can stop for three reasons:
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19 1. An invalid multibyte sequence has been encountered. In this case
20 (size_t) -1 is returned.
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22 2. n non-L'\0' wide characters have been stored at dest. In this case
23 the number of wide characters written to dest is returned, but the
24 shift state at this point is lost.
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26 3. The multibyte string has been completely converted, including the
27 terminating null wide character ('\0'). In this case the number of
28 wide characters written to dest, excluding the terminating null wide
29 character, is returned.
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31 The programmer must ensure that there is room for at least n wide char‐
32 acters at dest.
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34 If dest is NULL, n is ignored, and the conversion proceeds as above,
35 except that the converted wide characters are not written out to mem‐
36 ory, and that no length limit exists.
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38 In order to avoid the case 2 above, the programmer should make sure n
39 is greater or equal to mbstowcs(NULL,src,0)+1.
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42 The mbstowcs() function returns the number of wide characters that make
43 up the converted part of the wide-character string, not including the
44 terminating null wide character. If an invalid multibyte sequence was
45 encountered, (size_t) -1 is returned.
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48 C99.
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51 The behavior of mbstowcs() depends on the LC_CTYPE category of the cur‐
52 rent locale.
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54 The function mbsrtowcs(3) provides a better interface to the same func‐
55 tionality.
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58 mbsrtowcs(3), wcstombs(3)
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61 This page is part of release 3.53 of the Linux man-pages project. A
62 description of the project, and information about reporting bugs, can
63 be found at http://www.kernel.org/doc/man-pages/.
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67GNU 2011-09-28 MBSTOWCS(3)