totn C Functions

C Language: vfprintf function
(Formatted File Write Using Variable Argument List)

In the C Programming Language, the vfprintf function writes formatted output to stream using arg as the variable argument list.

Syntax

The syntax for the vfprintf function in the C Language is:

int vfprintf(FILE *stream, const char *format, va_list arg);

Parameters or Arguments

stream
The stream where the output will be written.
format

Describes the output as well as provides a placeholder to insert the formatted string. Here are a few examples:

FormatExplanationExample
%dDisplay an integer10
%fDisplays a floating-point number in fixed decimal format10.500000
%.1fDisplays a floating-point number with 1 digit after the decimal10.5
%eDisplay a floating-point number in exponential (scientific notation)1.050000e+01
%gDisplay a floating-point number in either fixed decimal or exponential format depending on the size of the number (will not display trailing zeros)10.5
arg
A variable argument list.

Returns

The vfprintf function returns the number of characters that was written. If an error occurs, it will return a negative value.

Required Header

In the C Language, the required header for the vfprintf function is:

#include <stdio.h>

Applies To

In the C Language, the vfprintf function can be used in the following versions:

  • ANSI/ISO 9899-1990

Similar Functions

Other C functions that are similar to the vfprintf function:

See Also

Other C functions that are noteworthy when dealing with the vfprintf function: