1WCSTOMBS(3) Linux Programmer's Manual WCSTOMBS(3)
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6 wcstombs - convert a wide-character string to a multibyte string
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9 #include <stdlib.h>
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11 size_t wcstombs(char *dest, const wchar_t *src, size_t n);
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14 If dest is not NULL, the wcstombs() function converts the wide-charac‐
15 ter string src to a multibyte string starting at dest. At most n bytes
16 are written to dest. The sequence of characters placed in dest begins
17 in the initial shift state. The conversion can stop for three reasons:
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19 1. A wide character has been encountered that can not be represented as
20 a multibyte sequence (according to the current locale). In this
21 case, (size_t) -1 is returned.
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23 2. The length limit forces a stop. In this case, the number of bytes
24 written to dest is returned, but the shift state at this point is
25 lost.
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27 3. The wide-character string has been completely converted, including
28 the terminating null wide character (L'\0'). In this case, the con‐
29 version ends in the initial shift state. The number of bytes writ‐
30 ten to dest, excluding the terminating null byte ('\0'), is
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33 The programmer must ensure that there is room for at least n bytes at
34 dest.
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36 If dest is NULL, n is ignored, and the conversion proceeds as above,
37 except that the converted bytes are not written out to memory, and no
38 length limit exists.
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40 In order to avoid the case 2 above, the programmer should make sure n
41 is greater than or equal to wcstombs(NULL,src,0)+1.
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44 The wcstombs() function returns the number of bytes that make up the
45 converted part of a multibyte sequence, not including the terminating
46 null byte. If a wide character was encountered which could not be con‐
47 verted, (size_t) -1 is returned.
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50 For an explanation of the terms used in this section, see
51 attributes(7).
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53 ┌───────────┬───────────────┬─────────┐
54 │Interface │ Attribute │ Value │
55 ├───────────┼───────────────┼─────────┤
56 │wcstombs() │ Thread safety │ MT-Safe │
57 └───────────┴───────────────┴─────────┘
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60 POSIX.1-2001, POSIX.1-2008, C99.
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63 The behavior of wcstombs() depends on the LC_CTYPE category of the cur‐
64 rent locale.
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66 The function wcsrtombs(3) provides a better interface to the same func‐
67 tionality.
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70 mblen(3), mbstowcs(3), mbtowc(3), wcsrtombs(3) wctomb(3)
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73 This page is part of release 5.04 of the Linux man-pages project. A
74 description of the project, information about reporting bugs, and the
75 latest version of this page, can be found at
76 https://www.kernel.org/doc/man-pages/.
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80GNU 2019-03-06 WCSTOMBS(3)