---

C Language: fprintf function
(Formatted File Write)

In the C Programming Language, the fprintf function writes formatted output to stream.

Syntax

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

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

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:

Format	Explanation	Example
%d	Display an integer	10
%f	Displays a floating-point number in fixed decimal format	10.500000
%.1f	Displays a floating-point number with 1 digit after the decimal	10.5
%e	Display a floating-point number in exponential (scientific notation)	1.050000e+01
%g	Display 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

Returns

The fprintf 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 fprintf function is:

#include <stdio.h>

Applies To

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

• ANSI/ISO 9899-1990

Similar Functions

Other C functions that are similar to the fprintf function:

• printf function <stdio.h>
• sprintf function <stdio.h>
• vfprintf function <stdio.h>
• vprintf function <stdio.h>
• vsprintf function <stdio.h>

See Also

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

• fscanf function <stdio.h>
• scanf function <stdio.h>
• sscanf function <stdio.h>