String Format Function

int fprintf(FILE* stream, const char *format[, argument ]...);

int fwprintf(FILE* stream, const wchar_t *format[, argument ]...);

int _ftprintf(FILE* stream, const TCHAR *format[, argument ]...);

Internationalization (I18n) Function Overview

The fprintf function formats a null-terminated string, using the format argument and the variable data arguments, and outputs it to stream stream. The number of bytes written is returned, or -1 if an error occurs.

fwprintf is the wide character version and returns the number of wide characters written.

_ftprintf is the Windows-only Generic version of the function; with the _MBCS or _UNICODE compiler flags determining its mapping to either fprintf or fwprintf.

I18n Issues

Use the appropriate version of the function as required for internationalization support, noting the following:

Prior to calling one of these functions, ensure that the current locale is set properly by calling setlocale, as string formatting is dependent on the LC_NUMERIC locale category. See String Formatting in C and C++ for a discussion on locale-sensitive formatting in internationalized applications.

Recommended Replacements*

ANSI UTF-8	fprintf
ANSI UTF-16	fwprintf
Microsoft Windows MBCS	fprintf
Microsoft Windows Unicode	fwprintf
Microsoft Windows Generic	_ftprintf

String Format Functions