w3resource

PHP: fprintf() function

Description

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

Previous: explode
Next: get_html_ translation_ table



PHP: Tips of the Day

PHP: How to write to the console in PHP?

Firefox

On Firefox you can use an extension called FirePHP which enables the logging and dumping of information from your PHP applications to the console. This is an addon to the awesome web development extension Firebug.

  • http://www.studytrails.com/blog/using-firephp-in-firefox-to-debug-php/

Chrome

However if you are using Chrome there is a PHP debugging tool called Chrome Logger or webug (webug has problems with the order of logs).

More recently Clockwork is in active development which extends the Developer Tools by adding a new panel to provide useful debugging and profiling information. It provides out of the box support for Laravel 4 and Slim 2 and support can be added via its extensible API.

Using Xdebug

A better way to debug your PHP would be via Xdebug. Most browsers provide helper extensions to help you pass the required cookie/query string to initialize the debugging process.

  • Chrome - Xdebug Helper
  • Firefox - The easiest Xdebug
  • Opera - Xdebug
  • Safari - Xdebug Toggler

Ref : https://bit.ly/3ck9rFg