wcrtomb - convert a wide character to a multibyte sequence


   #include <wchar.h>

   size_t wcrtomb(char *s, wchar_t wc, mbstate_t *ps);


   The  main  case for this function is when s is not NULL and wc is not a
   null wide character (L'\0').  In  this  case,  the  wcrtomb()  function
   converts  the  wide  character  wc  to its multibyte representation and
   stores it at the beginning of the character array pointed to by s.   It
   updates  the  shift state *ps, and returns the length of said multibyte
   representation, that is, the number of bytes written at s.

   A different case is when s is not NULL, but wc is a null wide character
   (L'\0').   In this case, the wcrtomb() function stores at the character
   array pointed to by s the shift sequence needed to bring  *ps  back  to
   the initial state, followed by a '\0' byte.  It updates the shift state
   *ps (i.e., brings it into the initial state), and returns the length of
   the shift sequence plus one, that is, the number of bytes written at s.

   A  third  case is when s is NULL.  In this case, wc is ignored, and the
   function effectively returns

       wcrtomb(buf, L'\0', ps)

   where buf is an internal anonymous buffer.

   In all of the above cases, if ps is  NULL,  a  static  anonymous  state
   known only to the wcrtomb() function is used instead.


   The  wcrtomb()  function  returns the number of bytes that have been or
   would have been written to the byte array at  s.   If  wc  can  not  be
   represented  as a multibyte sequence (according to the current locale),
   (size_t) -1 is returned, and errno set to EILSEQ.


   For  an  explanation  of  the  terms  used   in   this   section,   see

   Interface  Attribute      Value                      
   wcrtomb()  Thread safety  MT-Unsafe race:wcrtomb/!ps 


   POSIX.1-2001, POSIX.1-2008, C99.


   The  behavior  of  wcrtomb()  depends  on  the LC_CTYPE category of the
   current locale.

   Passing NULL as ps is not multithread safe.


   mbsinit(3), wcsrtombs(3)


   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


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.


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.