vsnprintf.c File Reference

Portable vsnprintf() implementation. More...

#include <stdio.h>
#include "flstring.h"

Functions
int	fl_snprintf (char *str, size_t size, const char *fmt,...)
int	fl_vsnprintf (char *buffer, size_t bufsize, const char *format, va_list ap)
	FLTK's platform independent wrapper for the vsnprintf() C library function.

Detailed Description

Portable vsnprintf() implementation.

Function Documentation

fl_vsnprintf()

int fl_vsnprintf	(	char *	buffer,
		size_t	bufsize,
		const char *	format,
		va_list	ap )

FLTK's platform independent wrapper for the vsnprintf() C library function.

This function guarantees:

• access to vsnprintf(), even on systems that don't have it (FLTK's own built-in code is used)
• Guarantees NUL termination. Even if string expands larger than the buffer, a terminating NUL is included, unlike some implementations of vsnprintf(), notably Microsoft Visual Studio (pre-2015), which can leave the string unterminated when truncated.

If the build environment for FLTK has vsnprintf(), fl_vsnprintf() is just a wrapper around the compiler's provided function. Otherwise, if the function is NOT available, FLTK's own built-in version is provided.

The FLTK built in provides these style options:

• %[ -+#']
• * – padding width
• .* – precision width
• Data types: h, l, ll, L
• Floating point formats: E, G, e, f, g
• Integer formats: B, X, b, d, i, o, u, x
• Pointer format: p
• String/char: c, s, n