mbstowcs(3p) — Linux manual page


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

       mbstowcs — convert a character string to a wide-character string

SYNOPSIS         top

       #include <stdlib.h>

       size_t mbstowcs(wchar_t *restrict pwcs, const char *restrict s,
           size_t n);

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.

       The mbstowcs() function shall convert a sequence of characters
       that begins in the initial shift state from the array pointed to
       by s into a sequence of corresponding wide-character codes and
       shall store not more than n wide-character codes into the array
       pointed to by pwcs.  No characters that follow a null byte (which
       is converted into a wide-character code with value 0) shall be
       examined or converted. Each character shall be converted as if by
       a call to mbtowc(), except that the shift state of mbtowc() is
       not affected.

       No more than n elements shall be modified in the array pointed to
       by pwcs.  If copying takes place between objects that overlap,
       the behavior is undefined.

       The behavior of this function shall be affected by the LC_CTYPE
       category of the current locale.  If pwcs is a null pointer,
       mbstowcs() shall return the length required to convert the entire
       array regardless of the value of n, but no values are stored.

RETURN VALUE         top

       If an invalid character is encountered, mbstowcs() shall return
       (size_t)-1 and shall set errno to indicate the error.

       Otherwise, mbstowcs() shall return the number of the array
       elements modified (or required if pwcs is null), not including a
       terminating 0 code, if any. The array shall not be zero-
       terminated if the value returned is n.

ERRORS         top

       The mbstowcs() function shall fail if:

       EILSEQ An invalid character sequence is detected. In the POSIX
              locale an [EILSEQ] error cannot occur since all byte
              values are valid characters.

       The following sections are informative.

EXAMPLES         top




RATIONALE         top




SEE ALSO         top

       mblen(3p), mbtowc(3p), wctomb(3p), wcstombs(3p)

       The Base Definitions volume of POSIX.1‐2017, stdlib.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                      MBSTOWCS(3P)

Pages that refer to this page: ctype.h(0p)stdlib.h(0p)mblen(3p)mbtowc(3p)setlocale(3p)wcstombs(3p)wctomb(3p)