WCSTOL
Section: POSIX Programmer's Manual (3P)
Updated: 2013
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PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
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.1-2008 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.1-2008,
<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 .
Index
- PROLOG
-
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- EXAMPLES
-
- APPLICATION USAGE
-
- RATIONALE
-
- FUTURE DIRECTIONS
-
- SEE ALSO
-
- COPYRIGHT
-
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