WPRINTF (3)
formatted wide character output conversion
SYNOPSIS
#include <stdio.h>
#include <wchar.h>
int wprintf (const wchar_t* format , ...);
int fwprintf (FILE* stream , const wchar_t* format , ...);
int swprintf (wchar_t* wcs , size_t maxlen ,
const wchar_t* format , ...);
#include <stdarg.h>
int vwprintf (const wchar_t* format , va_list args );
int vfwprintf (FILE* stream , const wchar_t* format , va_list args );
int vswprintf (wchar_t* wcs , size_t maxlen ,
const wchar_t* format , va_list args );
DESCRIPTION
The wprintf family of functions is the wide-character equivalent of the
printf family of functions. It performs formatted output of wide
characters.
The wprintf and vwprintf functions perform wide character output
to stdout. stdout must not be byte oriented; see function
fwide for more information.
The fwprintf and vfwprintf functions perform wide character output
to stream. stream must not be byte oriented; see function
fwide for more information.
The swprintf and vswprintf functions perform wide character output
to an array of wide characters.
The programmer must ensure that there is room for at least maxlen wide
characters at wcs.
These functions are like the printf, vprintf, fprintf,
vfprintf, sprintf, vsprintf functions except for the
following differences:
\(bu
The format string is a wide character string.
\(bu
The output consists of wide characters, not bytes.
\(bu
swprintf and vswprintf take a maxlen argument,
sprintf and vsprintf do not. (snprintf and vsnprintf
take a maxlen argument, but these functions do not return -1 upon
buffer overflow on Linux.)
The treatment of the conversion characters c and s is different:
c
If no
l
modifier is present, the
int
argument is converted to a wide character by a call to the
btowc
function, and the resulting wide character is written.
If an
l
modifier is present, the
wint_t
(wide character) argument is written.
s
If no
l
modifier is present: The
`` const char * ''
argument is expected to be a pointer to an array of character type
(pointer to a string) containing a multibyte character sequence beginning
in the initial shift state. Characters from the array are converted to
wide characters (each by a call to the
mbrtowc
function with a conversion state starting in the initial state before
the first byte). The resulting wide characters are written up to
(but not including) the terminating null wide character. If a precision is
specified, no more wide characters than the number specified are written.
Note that the precision determines the number of
wide characters
written, not the number of
bytes
or
screen positions .
The array must contain a terminating null byte, unless a precision is given
and it is so small that the number of converted wide characters reaches it
before the end of the array is reached. -- If an
l
modifier is present: The
`` const wchar_t * ''
argument is expected to be a pointer to an array of wide characters.
Wide characters from the array are written up to (but not including) a
terminating null wide character. If a precision is specified, no more than
the number specified are written. The array must contain a terminating null
wide character, unless a precision is given and it is smaller than or equal
to the number of wide characters in the array.
RETURN VALUE
The functions return the number of wide characters written, excluding the
terminating null wide character in case of the functions swprintf and
vswprintf. They return -1 when an error occurs.
CONFORMING TO
SEE ALSO
NOTES
The behaviour of wprintf et al. depends on the LC_CTYPE category of the
current locale.
If the format string contains non-ASCII wide characters, the program
will only work correctly if the LC_CTYPE category of the current locale at
run time is the same as the LC_CTYPE category of the current locale at
compile time. This is because the
wchar_t
representation is platform and locale dependent. (The GNU libc represents
wide characters using their Unicode (ISO-10646) code point, but other
platforms don't do this. Also, the use of ISO C99 universal character names
of the form \\unnnn does not solve this problem.) Therefore, in
internationalized programs, the format string should consist of ASCII
wide characters only, or should be constructed at run time in an
internationalized way (e.g. using
gettext
or
iconv ,
followed by
mbstowcs ).
man3/readv.3
'\"
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
'\" RCS: @(#) $Id: WrongNumArgs.3,v 1.2 1998/09/14 18:39:51 stanton Exp $
'\"
'\" The definitions below are for supplemental macros used in Tcl/Tk
'\" manual entries.
'\"
'\" .AP type name in/out ?indent?
'\" Start paragraph describing an argument to a library procedure.
'\" type is type of argument (int, etc.), in/out is either "in", "out",
'\" or "in/out" to describe whether procedure reads or modifies arg,
'\" and indent is equivalent to second arg of .IP (shouldn't ever be
'\" needed; use .AS below instead)
'\"
'\" .AS ?type? ?name?
'\" Give maximum sizes of arguments for setting tab stops. Type and
'\" name are examples of largest possible arguments that will be passed
'\" to .AP later. If args are omitted, default tab stops are used.
'\"
'\" .BS
'\" Start box enclosure. From here until next .BE, everything will be
'\" enclosed in one large box.
'\"
'\" .BE
'\" End of box enclosure.
'\"
'\" .CS
'\" Begin code excerpt.
'\"
'\" .CE
'\" End code excerpt.
'\"
'\" .VS ?version? ?br?
'\" Begin vertical sidebar, for use in marking newly-changed parts
'\" of man pages. The first argument is ignored and used for recording
'\" the version when the .VS was added, so that the sidebars can be
'\" found and removed when they reach a certain age. If another argument
'\" is present, then a line break is forced before starting the sidebar.
'\"
'\" .VE
'\" End of vertical sidebar.
'\"
'\" .DS
'\" Begin an indented unfilled display.
'\"
'\" .DE
'\" End of indented unfilled display.
'\"
'\" .SO
'\" Start of list of standard options for a Tk widget. The
'\" options follow on successive lines, in four columns separated
'\" by tabs.
'\"
'\" .SE
'\" End of list of standard options for a Tk widget.
'\"
'\" .OP cmdName dbName dbClass
'\" Start of description of a specific option. cmdName gives the
'\" option's name as specified in the class command, dbName gives
'\" the option's name in the option database, and dbClass gives
'\" the option's class in the option database.
'\"
'\" .UL arg1 arg2
'\" Print arg1 underlined, then print arg2 normally.
'\"
'\" RCS: @(#) $Id: man.macros,v 1.2 1998/09/14 18:39:54 stanton Exp $
'\"
'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
t .wh -1.3i ^B
^l \n(.l
b
'\" # Start an argument description
AP
!"\\$4"" .TP \\$4
\{\
!"\\$2"" .TP \\n()Cu
.TP 15
|