1WCSTOUL(3P) POSIX Programmer's Manual WCSTOUL(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 wcstoul, wcstoull — convert a wide-character string to an unsigned long
13
15 #include <wchar.h>
16 unsigned long wcstoul(const wchar_t *restrict nptr,
18 wchar_t **restrict endptr, int base);
19 unsigned long long wcstoull(const wchar_t *restrict nptr,
20 wchar_t **restrict endptr, int base);
21
23 The functionality described on this reference page is aligned with the
24 ISO C standard. Any conflict between the requirements described here
25 and the ISO C standard is unintentional. This volume of POSIX.1‐2017
26 defers to the ISO C standard.
27 The wcstoul() and wcstoull() functions shall convert the initial por‐
29 tion of the wide-character string pointed to by nptr to unsigned long
30 and unsigned long long representation, respectively. First, they shall
31 decompose the input wide-character string into three parts:
32 1. An initial, possibly empty, sequence of white-space wide-character
34 codes (as specified by iswspace())
35 2. A subject sequence interpreted as an integer represented in some
37 radix determined by the value of base
38 3. A final wide-character string of one or more unrecognized wide-
40 character codes, including the terminating null wide-character code
41 of the input wide-character string
42 Then they shall attempt to convert the subject sequence to an unsigned
44 integer, and return the result.
45 If base is 0, the expected form of the subject sequence is that of a
47 decimal constant, octal constant, or hexadecimal constant, any of which
48 may be preceded by a '+' or '-' sign. A decimal constant begins with a
49 non-zero digit, and consists of a sequence of decimal digits. An octal
50 constant consists of the prefix '0' optionally followed by a sequence
51 of the digits '0' to '7' only. A hexadecimal constant consists of the
52 prefix 0x or 0X followed by a sequence of the decimal digits and let‐
53 ters 'a' (or 'A') to 'f' (or 'F') with values 10 to 15 respectively.
54 If the value of base is between 2 and 36, the expected form of the sub‐
56 ject sequence is a sequence of letters and digits representing an inte‐
57 ger with the radix specified by base, optionally preceded by a '+' or
58 '-' sign, but not including an integer suffix. The letters from 'a' (or
59 'A') to 'z' (or 'Z') inclusive are ascribed the values 10 to 35; only
60 letters whose ascribed values are less than that of base shall be per‐
61 mitted. If the value of base is 16, the wide-character codes 0x or 0X
62 may optionally precede the sequence of letters and digits, following
63 the sign if present.
64 The subject sequence is defined as the longest initial subsequence of
66 the input wide-character string, starting with the first wide-character
67 code that is not white space and is of the expected form. The subject
68 sequence contains no wide-character codes if the input wide-character
69 string is empty or consists entirely of white-space wide-character
70 codes, or if the first wide-character code that is not white space is
71 other than a sign or a permissible letter or digit.
72 If the subject sequence has the expected form and base is 0, the
74 sequence of wide-character codes starting with the first digit shall be
75 interpreted as an integer constant. If the subject sequence has the
76 expected form and the value of base is between 2 and 36, it shall be
77 used as the base for conversion, ascribing to each letter its value as
78 given above. If the subject sequence begins with a <hyphen-minus>, the
79 value resulting from the conversion shall be negated. A pointer to the
80 final wide-character string shall be stored in the object pointed to by
81 endptr, provided that endptr is not a null pointer.
82 In other than the C or POSIX locale, additional locale-specific subject
84 sequence forms may be accepted.
85 If the subject sequence is empty or does not have the expected form, no
87 conversion shall be performed; the value of nptr shall be stored in the
88 object pointed to by endptr, provided that endptr is not a null
89 pointer.
90 These functions shall not change the setting of errno if successful.
92 Since 0, {ULONG_MAX}, and {ULLONG_MAX} are returned on error and 0 is
94 also a valid return on success, an application wishing to check for
95 error situations should set errno to 0, then call wcstoul() or
96 wcstoull(), then check errno.
97
99 Upon successful completion, the wcstoul() and wcstoull() functions
100 shall return the converted value, if any. If no conversion could be
101 performed, 0 shall be returned and errno may be set to indicate the
102 error. If the correct value is outside the range of representable val‐
103 ues, {ULONG_MAX} or {ULLONG_MAX} respectively shall be returned and
104 errno set to [ERANGE].
105
107 These functions shall fail if:
108 EINVAL The value of base is not supported.
110 ERANGE The value to be returned is not representable.
112 These functions may fail if:
114 EINVAL No conversion could be performed.
116 The following sections are informative.
118
120 None.
121
123 None.
124
126 None.
127
129 None.
130
132 fscanf(), iswalpha(), wcstod(), wcstol()
133 The Base Definitions volume of POSIX.1‐2017, <wchar.h>
135
137 Portions of this text are reprinted and reproduced in electronic form
138 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
139 table Operating System Interface (POSIX), The Open Group Base Specifi‐
140 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
141 Electrical and Electronics Engineers, Inc and The Open Group. In the
142 event of any discrepancy between this version and the original IEEE and
143 The Open Group Standard, the original IEEE and The Open Group Standard
144 is the referee document. The original Standard can be obtained online
145 at http://www.opengroup.org/unix/online.html .
146 Any typographical or formatting errors that appear in this page are
148 most likely to have been introduced during the conversion of the source
149 files to man page format. To report such errors, see https://www.ker‐
150 nel.org/doc/man-pages/reporting_bugs.html .
151IEEE/The Open Group 2017 WCSTOUL(3P)