vswprintf()

Updated: April 19, 2023

Write wide-character formatted output to a buffer (varargs)

Synopsis:

#include <wchar.h>
#include <stdarg.h>

int vswprintf( wchar_t * buf,
               size_t n,
               const wchar_t * format,
               va_list arg );

Arguments:

buf
A pointer to the buffer where you want to function to store the formatted string.
n
The maximum number of wide characters to store in the buffer, including a terminating null character.
format
A wide-character string that specifies the format of the output. The formatting string determines what additional arguments you need to provide. For more information, see printf().
arg
A variable-argument list of the additional arguments, which you must have initialized with the va_start() macro.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The vswprintf() function formats data under control of the format control string, and writes the result to buf.

The vswprint() function is the wide-character version of vsprintf(), and is a “varargs” version of swprintf().

Returns:

The number of wide characters written, excluding the terminating NUL, or a negative number if an error occurred (errno is set).

Classification:

ANSI, POSIX 1003.1

Safety:  
Cancellation point No
Interrupt handler Yes
Signal handler Yes
Thread Yes