mbrtowc(3)
NAME
mbrtowc - convert a multibyte sequence to a wide character
SYNOPSIS
#include <wchar.h> size_t mbrtowc(wchar_t *pwc, const char *s, size_t n, mbstate_t *ps);
DESCRIPTION
The main case for this function is when s is not NULL and pwc is not
NULL. In this case, the mbrtowc() function inspects at most n bytes of
the multibyte string starting at s, extracts the next complete
multibyte character, converts it to a wide character and stores it at
*pwc. It updates the shift state *ps. If the converted wide character
is not L'\0' (the null wide character), it returns the number of bytes
that were consumed from s. If the converted wide character is L'\0',
it resets the shift state *ps to the initial state and returns 0.
If the n bytes starting at s do not contain a complete multibyte
character, mbrtowc() returns (size_t) -2. This can happen even if n >=
MB_CUR_MAX, if the multibyte string contains redundant shift sequences.
If the multibyte string starting at s contains an invalid multibyte
sequence before the next complete character, mbrtowc() returns
(size_t) -1 and sets errno to EILSEQ. In this case, the effects on *ps
are undefined.
A different case is when s is not NULL but pwc is NULL. In this case,
the mbrtowc() function behaves as above, except that it does not store
the converted wide character in memory.
A third case is when s is NULL. In this case, pwc and n are ignored.
If the conversion state represented by *ps denotes an incomplete
multibyte character conversion, the mbrtowc() function returns
(size_t) -1, sets errno to EILSEQ, and leaves *ps in an undefined
state. Otherwise, the mbrtowc() function puts *ps in the initial state
and returns 0.
In all of the above cases, if ps is NULL, a static anonymous state
known only to the mbrtowc() function is used instead. Otherwise, *ps
must be a valid mbstate_t object. An mbstate_t object a can be
initialized to the initial state by zeroing it, for example using
memset(&a, 0, sizeof(a));
RETURN VALUE
The mbrtowc() function returns the number of bytes parsed from the multibyte sequence starting at s, if a non-L'\0' wide character was recognized. It returns 0, if a L'\0' wide character was recognized. It returns (size_t) -1 and sets errno to EILSEQ, if an invalid multibyte sequence was encountered. It returns (size_t) -2 if it couldn't parse a complete multibyte character, meaning that n should be increased.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). Interface Attribute Value mbrtowc() Thread safety MT-Unsafe race:mbrtowc/!ps
CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C99.
NOTES
The behavior of mbrtowc() depends on the LC_CTYPE category of the current locale.
SEE ALSO
mbsinit(3), mbsrtowcs(3)
COLOPHON
This page is part of release 4.09 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
