+'\" t -*- coding: UTF-8 -*-
.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
+.\" and Copyright 2014 Michael Kerrisk <mtk.manpages@gmail.com>
.\"
+.\" %%%LICENSE_START(GPLv2+_DOC_ONEPARA)
.\" This is free documentation; you can redistribute it and/or
.\" modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation; either version 2 of
.\" the License, or (at your option) any later version.
+.\" %%%LICENSE_END
.\"
.\" References consulted:
.\" GNU glibc-2 source code and manual
.\" OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html
.\" ISO/IEC 9899:1999
.\"
-.TH MBSTOWCS 3 1999-07-25 "GNU" "Linux Programmer's Manual"
+.TH MBSTOWCS 3 2014-03-18 "GNU" "Linux Programmer's Manual"
.SH NAME
mbstowcs \- convert a multibyte string to a wide-character string
.SH SYNOPSIS
.BI "size_t mbstowcs(wchar_t *" dest ", const char *" src ", size_t " n );
.fi
.SH DESCRIPTION
-If \fIdest\fP is not a NULL pointer,
+If
+.I dest
+is not NULL,
the
.BR mbstowcs ()
function converts the
-multibyte string \fIsrc\fP to a wide-character string starting at \fIdest\fP.
-At most \fIn\fP wide characters are written to \fIdest\fP.
+multibyte string
+.I src
+to a wide-character string starting at
+.IR dest .
+At most
+.I n
+wide characters are written to
+.IR dest .
The conversion starts
in the initial state.
The conversion can stop for three reasons:
.IP 1. 3
An invalid multibyte sequence has been encountered.
-In this case
+In this case,
.I (size_t)\ \-1
is returned.
.IP 2.
-\fIn\fP non-L\(aq\\0\(aq wide characters have been stored at \fIdest\fP.
-In this
-case the number of wide characters written to \fIdest\fP is returned, but the
+.I n
+non-L\(aq\\0\(aq wide characters have been stored at
+.IR dest .
+In this case, the number of wide characters written to
+.I dest
+is returned, but the
shift state at this point is lost.
.IP 3.
The multibyte string has been completely converted, including the
-terminating \(aq\\0\(aq.
-In this case the number of wide characters written to
-\fIdest\fP, excluding the terminating L\(aq\\0\(aq character, is returned.
+terminating null wide character (\(aq\\0\(aq).
+In this case, the number of wide characters written to
+.IR dest ,
+excluding the terminating null wide character, is returned.
.PP
-The programmer must ensure that there is room for at least \fIn\fP wide
-characters at \fIdest\fP.
+The programmer must ensure that there is room for at least
+.I n
+wide
+characters at
+.IR dest .
.PP
-If \fIdest\fP is NULL, \fIn\fP is ignored, and the conversion proceeds as
+If
+.IR dest
+is NULL,
+.I n
+is ignored, and the conversion proceeds as
above, except that the converted wide characters are not written out to memory,
and that no length limit exists.
.PP
-In order to avoid the case 2 above, the programmer should make sure \fIn\fP is
-greater or equal to \fImbstowcs(NULL,src,0)+1\fP.
-.SH "RETURN VALUE"
+In order to avoid the case 2 above, the programmer should make sure
+.I n
+is
+greater than or equal to
+.IR "mbstowcs(NULL,src,0)+1" .
+.SH RETURN VALUE
The
.BR mbstowcs ()
function returns the number of wide characters that make
encountered,
.I (size_t)\ \-1
is returned.
-.SH "CONFORMING TO"
+.SH CONFORMING TO
C99.
.SH NOTES
The behavior of
.BR mbsrtowcs (3)
provides a better interface to the same
functionality.
-.SH "SEE ALSO"
-.BR mbsrtowcs (3)
+.SH EXAMPLE
+The program below illustrates the use of
+.BR mbstowcs (),
+as well as some of the wide character classification functions.
+An example run is the following:
+.in +4n
+.nf
+
+$ ./t_mbstowcs de_DE.UTF\-8 Grüße!
+Length of source string (excluding terminator):
+ 8 bytes
+ 6 multibyte characters
+
+Wide character string is: Grüße! (6 characters)
+ G alpha upper
+ r alpha lower
+ ü alpha lower
+ ß alpha lower
+ e alpha lower
+ ! !alpha
+.fi
+.in
+.SS Program source
+.nf
+#include <locale.h>
+#include <wchar.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+int
+main(int argc, char *argv[])
+{
+ size_t mbslen; /* Number of multibyte characters in source */
+ wchar_t *wcs; /* Pointer to converted wide character string */
+ wchar_t *wp;
+
+ if (argc < 3) {
+ fprintf(stderr, "Usage: %s <locale> <string>\\n", argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ /* Apply the specified locale */
+
+ if (setlocale(LC_ALL, argv[1]) == NULL) {
+ perror("setlocale");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Calculate the length required to hold argv[2] converted to
+ a wide character string */
+
+ mbslen = mbstowcs(NULL, argv[2], 0);
+ if (mbslen == (size_t) \-1) {
+ perror("mbstowcs");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Describe the source string to the user */
+
+ printf("Length of source string (excluding terminator):\\n");
+ printf(" %zu bytes\\n", strlen(argv[2]));
+ printf(" %zu multibyte characters\\n\\n", mbslen);
+
+ /* Allocate wide character string of the desired size. Add 1
+ to allow for terminating null wide character (L\(aq\\0\(aq). */
+
+ wcs = calloc(mbslen + 1, sizeof(wchar_t));
+ if (wcs == NULL) {
+ perror("calloc");
+ exit(EXIT_FAILURE);
+ }
+
+ /* Convert the multibyte character string in argv[2] to a
+ wide character string */
+
+ if (mbstowcs(wcs, argv[2], mbslen + 1) == (size_t) \-1) {
+ perror("mbstowcs");
+ exit(EXIT_FAILURE);
+ }
+
+ printf("Wide character string is: %ls (%zu characters)\\n",
+ wcs, mbslen);
+
+ /* Now do some inspection of the classes of the characters in
+ the wide character string */
+
+ for (wp = wcs; *wp != 0; wp++) {
+ printf(" %lc ", (wint_t) *wp);
+
+ if (!iswalpha(*wp))
+ printf("!");
+ printf("alpha ");
+
+ if (iswalpha(*wp)) {
+ if (iswupper(*wp))
+ printf("upper ");
+
+ if (iswlower(*wp))
+ printf("lower ");
+ }
+
+ putchar(\(aq\\n\(aq);
+ }
+
+ exit(EXIT_SUCCESS);
+}
+.fi
+.SH SEE ALSO
+.BR mblen (3),
+.BR mbsrtowcs (3),
+.BR mbtowc (3),
+.BR wctomb (3),
+.BR wcstombs (3)
+.SH COLOPHON
+This page is part of release 3.68 of the Linux
+.I man-pages
+project.
+A description of the project,
+information about reporting bugs,
+and the latest version of this page,
+can be found at
+\%http://www.kernel.org/doc/man\-pages/.
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