NAMEwprintf, fwprintf, swprintf, vwprintf, vfwprintf, vswprintf - 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, ...); 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); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): All functions shown above: _XOPEN_SOURCE >= 500 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L; or cc -std=c99
DESCRIPTIONThe wprintf() family of functions is the wide-character equivalent of the printf(3) 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 fwide(3) for more information. The fwprintf() and vfwprintf() functions perform wide-character output to stream. stream must not be byte oriented; see fwide(3) 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(3), vprintf(3), fprintf(3), vfprintf(3), sprintf(3), vsprintf(3) functions except for the following differences: +
RETURN VALUEThe 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.
NOTESThe behavior 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 glibc represents wide characters using their Unicode (ISO-10646) code point, but other platforms don't do this. Also, the use of 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(3) or iconv(3), followed by mbstowcs(3)).
SEE ALSOfprintf(3), fputwc(3), fwide(3), printf(3), snprintf(3).
COLOPHONThis page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at //www.kernel.org/doc/man-pages/. VFWPRINTF(3)