Description

The C library function, The vprintf() function formats a series of strings and numeric values and builds a string to writes a formatted string to the stdout stream using arg as the variable argument list.

Declaration

Following is the declaration for vprintf() function.

int vprintf(const char *format, va_list arg);

Parameters

Format - This is the String that contains the text to be written to buffer. It can optionally contain embedded format tags that are replaced by the values specified in subsequent additional arguments and formatted as requested.

A format specifier follows this prototype:

%[flags][width][.precision][length]specifier

Where the specifier character at the end is the most significant component, since it defines the type and the interpretation of its corresponding argument:

The format specifier can also contain sub-specifiers: flags, width, .precision and modifiers (in that order), which are optional and follow these specifications:

arg - The arg argument points to a list of arguments that are converted and output according to the corresponding format specifications in format.

Return Value

The vprintf function returns the number of characters actually written to the output stream. otherwise a negative number is returned.

Example

#include <stdio.h>
#include <stdarg.h>

void WriteFormatted ( const char * format, ... )
{
  va_list args;
  va_start (args, format);
  vprintf (format, args);
  va_end (args);
}

int main ()
{
   WriteFormatted ("Call with variable argument.\n");
  

   return 0;
}

Output

Call with variable argument.