PHP: fprintf() function

Last update on October 03 2024 11:33:54 (UTC/GMT +8 hours)

PHP: Write a formatted string to a stream

The fprintf() function writes a formatted string to a specified stream resource.

Version:

(PHP 5 )

Syntax:

fprintf(file_handle, main_string, arg1, arg2, arg3... )

Parameters:

Name	Description	Required / Optional	Type
file_handle	When a file is successfully opened by fopen() or fsockopen() it returns a resource ID, which is referred as file handler or file pointer.	Required	Resource
main_string	Each conversion specification starts with a single percent sign (%) and ends with the following conversion characters. % - returns a percent sign. b - the argument is treated as an integer and display it as a binary number. c - the argument is treated as an integer and display it as a ASCII value. d - the argument is treated as an integer and display as a signed decimal number. e - the argument is treated as scientific notation (e.g. 1.2e+2). E - the argument treated as scientific notation (e.g.1.2E+2). u - the argument is treated as an integer, and display as an unsigned decimal number. f- the argument is treated as a float, and display as a floating-point number. (local aware) F - the argument is treated as a float, and display as a floating-point number (non-locale aware). g - shorter of %e and %f. G - shorter of %E and %f. o- the argument is treated as an integer, and display as an octal number. s - the argument is treated as string and display as a string. x - the argument is treated as an integer and display as a hexadecimal number (with lowercase letters). X - the argument is treated as an integer and display as a hexadecimal number (with uppercase letters). Optional specification : Sign specifier : display a sign (+ or -) in front a number. By default, a - sign is used in front of a number if it is negative. Padding character : Default character is space. An alternate padding character can be specified by prefixing it with a single quote. Alignment specifier. : - character makes the alignment left-justified. The default is right justified. Width specifier : An integer number specifies the width of the field. Precision specifier : The argument specifies how many decimal number should be displayed for floating numbers. When using this specifier on a string, it acts as a cutoff point, setting a maximum character limit to the string.	Required	String
arg1	The argument to be added as the first %-sign in the formatted string.	Required	Mixed*
arg2,arg3..	These arguments will be added as second %, third % etc. in the formatted string.	Optional	Mixed*

*Mixed : Mixed indicates that a parameter may accept multiple (but not necessarily all) types.

Return value

The length of the output string.

Value Type : Integer.

Example :

<?php
$string1 = 'My Roll No. is :';
$roll_no = 22;
$file_handler = fopen('testvf.txt','w');
fprintf($file_handler, '%s   %u', $string1, $roll_no);
fclose($file_handler);
// Let open the file once again and read the content.
$file_name = 'testvf.txt';
$file_handler = fopen($file_name, 'r');
$file_data = fread($file_handler, 1024);
fclose($file_handler);
echo ($file_data);
?>

Output :

My Roll No. is :   22

View the example in the browser

See also

PHP Function Reference

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