1WCSRTOMBS(3P) POSIX Programmer's Manual WCSRTOMBS(3P)
2
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.
10
12 wcsnrtombs, wcsrtombs — convert a wide-character string to a character
13 string (restartable)
14
16 #include <wchar.h>
17 size_t wcsnrtombs(char *restrict dst, const wchar_t **restrict src,
19 size_t nwc, size_t len, mbstate_t *restrict ps);
20 size_t wcsrtombs(char *restrict dst, const wchar_t **restrict src,
21 size_t len, mbstate_t *restrict ps);
22
24 For wcsrtombs(): The functionality described on this reference page is
25 aligned with the ISO C standard. Any conflict between the requirements
26 described here and the ISO C standard is unintentional. This volume of
27 POSIX.1‐2017 defers to the ISO C standard.
28 The wcsrtombs() function shall convert a sequence of wide characters
30 from the array indirectly pointed to by src into a sequence of corre‐
31 sponding characters, beginning in the conversion state described by the
32 object pointed to by ps. If dst is not a null pointer, the converted
33 characters shall then be stored into the array pointed to by dst. Con‐
34 version continues up to and including a terminating null wide charac‐
35 ter, which shall also be stored. Conversion shall stop earlier in the
36 following cases:
37 * When a code is reached that does not correspond to a valid charac‐
39 ter
40 * When the next character would exceed the limit of len total bytes
42 to be stored in the array pointed to by dst (and dst is not a null
43 pointer)
44 Each conversion shall take place as if by a call to the wcrtomb() func‐
46 tion.
47 If dst is not a null pointer, the pointer object pointed to by src
49 shall be assigned either a null pointer (if conversion stopped due to
50 reaching a terminating null wide character) or the address just past
51 the last wide character converted (if any). If conversion stopped due
52 to reaching a terminating null wide character, the resulting state
53 described shall be the initial conversion state.
54 If ps is a null pointer, the wcsrtombs() function shall use its own
56 internal mbstate_t object, which is initialized at program start-up to
57 the initial conversion state. Otherwise, the mbstate_t object pointed
58 to by ps shall be used to completely describe the current conversion
59 state of the associated character sequence.
60 The wcsnrtombs() and wcsrtombs() functions need not be thread-safe if
62 called with a NULL ps argument.
63 The wcsnrtombs() function shall be equivalent to the wcsrtombs() func‐
65 tion, except that the conversion is limited to the first nwc wide char‐
66 acters.
67 The wcsrtombs() function shall not change the setting of errno if suc‐
69 cessful.
70 The behavior of these functions shall be affected by the LC_CTYPE cate‐
72 gory of the current locale.
73 The implementation shall behave as if no function defined in System
75 Interfaces volume of POSIX.1‐2017 calls these functions.
76
78 If conversion stops because a code is reached that does not correspond
79 to a valid character, an encoding error occurs. In this case, these
80 functions shall store the value of the macro [EILSEQ] in errno and
81 return (size_t)-1; the conversion state is undefined. Otherwise, these
82 functions shall return the number of bytes in the resulting character
83 sequence, not including the terminating null (if any).
84
86 These functions shall fail if:
87 EILSEQ A wide-character code does not correspond to a valid character.
89 These functions may fail if:
91 EINVAL ps points to an object that contains an invalid conversion
93 state.
94 The following sections are informative.
96
98 None.
99
101 None.
102
104 None.
105
107 None.
108
110 mbsinit(), wcrtomb()
111 The Base Definitions volume of POSIX.1‐2017, <wchar.h>
113
115 Portions of this text are reprinted and reproduced in electronic form
116 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
117 table Operating System Interface (POSIX), The Open Group Base Specifi‐
118 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
119 Electrical and Electronics Engineers, Inc and The Open Group. In the
120 event of any discrepancy between this version and the original IEEE and
121 The Open Group Standard, the original IEEE and The Open Group Standard
122 is the referee document. The original Standard can be obtained online
123 at http://www.opengroup.org/unix/online.html .
124 Any typographical or formatting errors that appear in this page are
126 most likely to have been introduced during the conversion of the source
127 files to man page format. To report such errors, see https://www.ker‐
128 nel.org/doc/man-pages/reporting_bugs.html .
129IEEE/The Open Group 2017 WCSRTOMBS(3P)