1WCRTOMB(3P) POSIX Programmer's Manual WCRTOMB(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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12 wcrtomb - convert a wide-character code to a character (restartable)
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15 #include <stdio.h>
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17 size_t wcrtomb(char *restrict s, wchar_t wc, mbstate_t *restrict ps);
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21 If s is a null pointer, the wcrtomb() function shall be equivalent to
22 the call:
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25 wcrtomb(buf, L'\0', ps)
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27 where buf is an internal buffer.
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29 If s is not a null pointer, the wcrtomb() function shall determine the
30 number of bytes needed to represent the character that corresponds to
31 the wide character given by wc (including any shift sequences), and
32 store the resulting bytes in the array whose first element is pointed
33 to by s. At most {MB_CUR_MAX} bytes are stored. If wc is a null wide
34 character, a null byte shall be stored, preceded by any shift sequence
35 needed to restore the initial shift state. The resulting state
36 described shall be the initial conversion state.
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38 If ps is a null pointer, the wcrtomb() function shall use its own
39 internal mbstate_t object, which is initialized at program start-up to
40 the initial conversion state. Otherwise, the mbstate_t object pointed
41 to by ps shall be used to completely describe the current conversion
42 state of the associated character sequence. The implementation shall
43 behave as if no function defined in this volume of IEEE Std 1003.1-2001
44 calls wcrtomb().
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46 If the application uses any of the _POSIX_THREAD_SAFE_FUNCTIONS or
47 _POSIX_THREADS functions, the application shall ensure that the wcr‐
48 tomb() function is called with a non-NULL ps argument.
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50 The behavior of this function shall be affected by the LC_CTYPE cate‐
51 gory of the current locale.
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54 The wcrtomb() function shall return the number of bytes stored in the
55 array object (including any shift sequences). When wc is not a valid
56 wide character, an encoding error shall occur. In this case, the func‐
57 tion shall store the value of the macro [EILSEQ] in errno and shall
58 return (size_t)-1; the conversion state shall be undefined.
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61 The wcrtomb() function may fail if:
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63 EINVAL ps points to an object that contains an invalid conversion
64 state.
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66 EILSEQ Invalid wide-character code is detected.
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69 The following sections are informative.
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72 None.
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75 None.
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78 None.
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81 None.
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84 mbsinit(), the Base Definitions volume of IEEE Std 1003.1-2001,
85 <wchar.h>
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88 Portions of this text are reprinted and reproduced in electronic form
89 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
90 -- Portable Operating System Interface (POSIX), The Open Group Base
91 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
92 Electrical and Electronics Engineers, Inc and The Open Group. In the
93 event of any discrepancy between this version and the original IEEE and
94 The Open Group Standard, the original IEEE and The Open Group Standard
95 is the referee document. The original Standard can be obtained online
96 at http://www.opengroup.org/unix/online.html .
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100IEEE/The Open Group 2003 WCRTOMB(3P)