wcstol(3posix)
NAME
wcstol, wcstoll --- convert a wide-character string to a long integer
SYNOPSIS
#include <wchar.h>
long wcstol(const wchar_t *restrict nptr, wchar_t **restrict endptr,
int base);
long long wcstoll(const wchar_t *restrict nptr,
wchar_t **restrict endptr, int base);
DESCRIPTION
The functionality described on this reference page is aligned with the
ISO C standard. Any conflict between the requirements described here
and the ISO C standard is unintentional. This volume of POSIX.12008
defers to the ISO C standard.
These functions shall convert the initial portion of the wide-character
string pointed to by nptr to long and long long, respectively. First,
they shall decompose the input string into three parts:
1. An initial, possibly empty, sequence of white-space wide-character
codes (as specified by iswspace())
2. A subject sequence interpreted as an integer represented in some
radix determined by the value of base
3. A final wide-character string of one or more unrecognized wide-
character codes, including the terminating null wide-character code
of the input wide-character string
Then they shall attempt to convert the subject sequence to an integer,
and return the result.
If base is 0, the expected form of the subject sequence is that of a
decimal constant, octal constant, or hexadecimal constant, any of which
may be preceded by a '+' or '' sign. A decimal constant begins with a
non-zero digit, and consists of a sequence of decimal digits. An octal
constant consists of the prefix '0' optionally followed by a sequence
of the digits '0' to '7' only. A hexadecimal constant consists of the
prefix 0x or 0X followed by a sequence of the decimal digits and
letters 'a' (or 'A') to 'f' (or 'F') with values 10 to 15 respectively.
If the value of base is between 2 and 36, the expected form of the
subject sequence is a sequence of letters and digits representing an
integer with the radix specified by base, optionally preceded by a '+'
or '' sign, but not including an integer suffix. The letters from 'a'
(or 'A') to 'z' (or 'Z') inclusive are ascribed the values 10 to 35;
only letters whose ascribed values are less than that of base shall be
permitted. If the value of base is 16, the wide-character code
representations of 0x or 0X may optionally precede the sequence of
letters and digits, following the sign if present.
The subject sequence is defined as the longest initial subsequence of
the input wide-character string, starting with the first non-white-
space wide-character code that is of the expected form. The subject
sequence contains no wide-character codes if the input wide-character
string is empty or consists entirely of white-space wide-character
code, or if the first non-white-space wide-character code is other than
a sign or a permissible letter or digit.
If the subject sequence has the expected form and base is 0, the
sequence of wide-character codes starting with the first digit shall be
interpreted as an integer constant. If the subject sequence has the
expected form and the value of base is between 2 and 36, it shall be
used as the base for conversion, ascribing to each letter its value as
given above. If the subject sequence begins with a minus-sign, the
value resulting from the conversion shall be negated. A pointer to the
final wide-character string shall be stored in the object pointed to by
endptr, provided that endptr is not a null pointer.
In other than the C or POSIX locales, other implementation-defined
subject sequences may be accepted.
If the subject sequence is empty or does not have the expected form, no
conversion shall be performed; the value of nptr shall be stored in the
object pointed to by endptr, provided that endptr is not a null
pointer.
These functions shall not change the setting of errno if successful.
Since 0, {LONG_MIN} or {LLONG_MIN} and {LONG_MAX} or {LLONG_MAX} are
returned on error and are also valid returns on success, an application
wishing to check for error situations should set errno to 0, then call
wcstol() or wcstoll(), then check errno.
RETURN VALUE
Upon successful completion, these functions shall return the converted
value, if any. If no conversion could be performed, 0 shall be returned
and errno may be set to indicate the error. If the correct value is
outside the range of representable values, {LONG_MIN}, {LONG_MAX},
{LLONG_MIN}, or {LLONG_MAX} shall be returned (according to the sign of
the value), and errno set to [ERANGE].
ERRORS
These functions shall fail if: EINVAL The value of base is not supported. ERANGE The value to be returned is not representable. These functions may fail if: EINVAL No conversion could be performed. The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
fscanf(), iswalpha(), wcstod() The Base Definitions volume of POSIX.12008, <wchar.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html . Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .
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