man3/wctomb.3

   1 .\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
   2 .\"
   3 .\" This is free documentation; you can redistribute it and/or
   4 .\" modify it under the terms of the GNU General Public License as
   5 .\" published by the Free Software Foundation; either version 2 of
   6 .\" the License, or (at your option) any later version.
   7 .\"
   8 .\" References consulted:
   9 .\"   GNU glibc-2 source code and manual
  10 .\"   Dinkumware C library reference http://www.dinkumware.com/
  11 .\"   OpenGroup's Single Unix specification http://www.UNIX-systems.org/online.html
  12 .\"   ISO/IEC 9899:1999
  13 .\"
  14 .TH WCTOMB 3  1999-07-25 "GNU" "Linux Programmer's Manual"
  15 .SH NAME
  16 wctomb \- convert a wide character to a multibyte sequence
  17 .SH SYNOPSIS
  18 .nf
  19 .B #include <stdlib.h>
  20 .sp
  21 .BI "int wctomb(char *" s ", wchar_t " wc );
  22 .fi
  23 .SH DESCRIPTION
  24 If \fIs\fP is not NULL, the \fBwctomb\fP function converts the wide character
  25 \fIwc\fP to its multibyte representation and stores it at the beginning of
  26 the character array pointed to by \fIs\fP. It updates the shift state, which
  27 is stored in a static anonymous variable only known to the wctomb function,
  28 and returns the length of said multibyte representation, i.e. the number of
  29 bytes written at \fIs\fP.
  30 .PP
  31 The programmer must ensure that there is room for at least \fBMB_CUR_MAX\fP
  32 bytes at \fIs\fP.
  33 .PP
  34 If \fIs\fP is NULL, the \fBwctomb\fP function
  35 .\" The Dinkumware doc and the Single Unix specification say this, but
  36 .\" glibc doesn't implement this.
  37 resets the shift state, only known to this function, to the initial state, and
  38 returns non-zero if the encoding has non-trivial shift state, or zero if the
  39 encoding is stateless.
  40 .SH "RETURN VALUE"
  41 If \fIs\fP is not NULL, the \fBwctomb\fP function returns the number of bytes
  42 that have been written to the byte array at \fIs\fP. If \fIwc\fP can not be
  43 represented as a multibyte sequence (according to the current locale), \-1 is
  44 returned.
  45 .PP
  46 If \fIs\fP is NULL, the \fBwctomb\fP function returns non-zero if the
  47 encoding has non-trivial shift state, or zero if the encoding is stateless.
  48 .SH "CONFORMING TO"
  49 ISO/ANSI C, UNIX98
  50 .SH "SEE ALSO"
  51 .BR MB_CUR_MAX (3),
  52 .BR wcrtomb (3),
  53 .BR wcstombs (3)
  54 .SH NOTES
  55 The behaviour of \fBwctomb\fP depends on the LC_CTYPE category of the
  56 current locale.
  57 .PP
  58 This function is not multi-thread safe. The function \fBwcrtomb\fP provides
  59 a better interface to the same functionality.