1WCSNRTOMBS(3) Linux Programmer's Manual WCSNRTOMBS(3)
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6 wcsnrtombs - convert a wide character string to a multibyte string
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9 #include <wchar.h>
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11 size_t wcsnrtombs(char *dest, const wchar_t **src, size_t nwc,
12 size_t len, mbstate_t *ps);
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15 The wcsnrtombs() function is like the wcsrtombs() function, except that
16 the number of wide characters to be converted, starting at *src, is
17 limited to nwc.
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19 If dest is not a NULL pointer, the wcsnrtombs() function converts at
20 most nwc wide characters from the wide-character string *src to a
21 multibyte string starting at dest. At most len bytes are written to
22 dest. The shift state *ps is updated. The conversion is effectively
23 performed by repeatedly calling wcrtomb(dest,*src,ps), as long as this
24 call succeeds, and then incrementing dest by the number of bytes writ‐
25 ten and *src by one. The conversion can stop for three reasons:
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27 1. A wide character has been encountered that can not be represented as
28 a multibyte sequence (according to the current locale). In this case
29 *src is left pointing to the invalid wide character, (size_t)(-1) is
30 returned, and errno is set to EILSEQ.
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32 2. nwc wide characters have been converted without encountering a
33 L'\0', or the length limit forces a stop. In this case *src is left
34 pointing to the next wide character to be converted, and the number of
35 bytes written to dest is returned.
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37 3. The wide-character string has been completely converted, including
38 the terminating L'\0' (which has the side effect of bringing back *ps
39 to the initial state). In this case *src is set to NULL, and the number
40 of bytes written to dest, excluding the terminating '\0' byte, is
41 returned.
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43 If dest is NULL, len is ignored, and the conversion proceeds as above,
44 except that the converted bytes are not written out to memory, and that
45 no destination length limit exists.
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47 In both of the above cases, if ps is a NULL pointer, a static anonymous
48 state only known to the wcsnrtombs function is used instead.
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50 The programmer must ensure that there is room for at least len bytes at
51 dest.
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54 The wcsnrtombs() function returns the number of bytes that make up the
55 converted part of multibyte sequence, not including the terminating
56 null byte. If a wide character was encountered which could not be con‐
57 verted, (size_t)(-1) is returned, and errno set to EILSEQ.
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60 This function is a GNU extension.
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63 iconv(3), wcsrtombs(3)
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66 The behaviour of wcsnrtombs() depends on the LC_CTYPE category of the
67 current locale.
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69 Passing NULL as ps is not multi-thread safe.
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73GNU 1999-07-25 WCSNRTOMBS(3)