wcstol(3p) — Linux manual page


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

PROLOG         top

       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         top

       wcstol, wcstoll — convert a wide-character string to a long

SYNOPSIS         top

       #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         top

       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 '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 <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

       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         top

       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

ERRORS         top

       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         top




RATIONALE         top




SEE ALSO         top

       fscanf(3p), iswalpha(3p), wcstod(3p)

       The Base Definitions volume of POSIX.1‐2017, wchar.h(0p)

COPYRIGHT         top

       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(3P)

Pages that refer to this page: wchar.h(0p)fwscanf(3p)wcstod(3p)wcstoimax(3p)wcstoll(3p)wcstoul(3p)