1MBSRTOWCS(3)               Linux Programmer's Manual              MBSRTOWCS(3)
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NAME

6       mbsrtowcs - convert a multibyte string to a wide-character string
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SYNOPSIS

9       #include <wchar.h>
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11       size_t mbsrtowcs(wchar_t *dest, const char **src,
12                         size_t len, mbstate_t *ps);
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DESCRIPTION

15       If  dest  is  not a NULL pointer, the mbsrtowcs() function converts the
16       multibyte string *src to a wide-character string starting at dest.   At
17       most  len  wide characters are written to dest.  The shift state *ps is
18       updated.  The conversion is effectively performed by repeatedly calling
19       mbrtowc(dest,  *src, n, ps) where n is some positive number, as long as
20       this call succeeds, and then incrementing dest by one and *src  by  the
21       number of bytes consumed.  The conversion can stop for three reasons:
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23       1. An  invalid  multibyte  sequence has been encountered.  In this case
24          *src is left pointing to the invalid multibyte sequence, (size_t) -1
25          is returned, and errno is set to EILSEQ.
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27       2. len  non-L'\0'  wide  characters  have been stored at dest.  In this
28          case *src is left pointing to the next multibyte sequence to be con‐
29          verted,  and  the  number  of  wide  characters  written  to dest is
30          returned.
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32       3. The multibyte string has been completely  converted,  including  the
33          terminating  '\0' (which has the side effect of bringing back *ps to
34          the initial state).  In this case *src is set to NULL, and the  num‐
35          ber  of  wide  characters written to dest, excluding the terminating
36          L'\0' character, is returned.
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38       If dest is NULL, len is ignored, and the conversion proceeds as  above,
39       except  that  the converted wide characters are not written out to mem‐
40       ory, and that no length limit exists.
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42       In both of the above cases, if ps is a NULL pointer, a static anonymous
43       state only known to the mbsrtowcs() function is used instead.
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45       The  programmer  must  ensure  that there is room for at least len wide
46       characters at dest.
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RETURN VALUE

49       The mbsrtowcs() function returns the number  of  wide  characters  that
50       make  up the converted part of the wide-character string, not including
51       the terminating null wide character.  If an invalid multibyte  sequence
52       was encountered, (size_t) -1 is returned, and errno set to EILSEQ.
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CONFORMING TO

55       C99.
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NOTES

58       The  behavior  of  mbsrtowcs()  depends on the LC_CTYPE category of the
59       current locale.
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61       Passing NULL as ps is not multithread safe.
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SEE ALSO

64       iconv(3), mbsnrtowcs(3), mbstowcs(3)
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COLOPHON

67       This page is part of release 3.25 of the Linux  man-pages  project.   A
68       description  of  the project, and information about reporting bugs, can
69       be found at http://www.kernel.org/doc/man-pages/.
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73GNU                               1999-07-25                      MBSRTOWCS(3)
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