WCSTOL(3)                  POSIX Programmer's Manual                 WCSTOL(3)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

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.1-2017
       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 ''00'' optionally followed by a sequence
       of the digits ''00'' to ''77'' 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 <hyphen-minus>, 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 locale, additional locale-specific subject
       sequence forms 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.1-2017, <wchar.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  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.opengroup.org/unix/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 .



IEEE/The Open Group                  2017                            WCSTOL(3)
