PHP fpassthru( ) Function

The fpassthru() function in PHP is an inbuilt function which is used to read data from a current position from a specified file until end of file and then write the result to the output buffer. The file which has to be read is sent as a parameter to the fpassthru() function and it returns the number of characters passed on success or FALSE on failure. Syntax:

int fpassthru ( $file )

Parameters Used: The fpassthru() function in PHP accepts one parameter.

• file: It is a mandatory parameter which specifies the file.

Return Value:

• It returns the number of characters passed on success or FALSE on failure.

Exceptions

• The file should be opened in binary mode while using the fpassthru() function on a binary file on Windows.
• rewind() function should be called to set the file pointer to the beginning of the file if you have already written to the file.
• the readfile() function should be used if you want to dump the contents of a file to the output buffer without modifying it.

Below is the implementation of fpassthru() function. Suppose a file gfg.txt contains the following content :

Geeksforgeeks Portal for Geeks!

Program 1: php

<?php
// opening a file in read only mode
$myfile = fopen("gfg.txt", "rb");

// Reading the first line of the file
fgets($myfile);

// Sending the rest of the file 
// contents to the output buffer
echo fpassthru($myfile);

// closing the file
fclose($myfile);
?>

Output:

Portal for Geeks!17

Note: 17 indicates the number of characters passed. Program 2: php

<?php
$myfile = fopen("http://www.geeksforgeeks.com", "rb");

// dumping index page of the server
fpassthru($myfile);
?>

Reference : https://www.php.net/manual/en/function.fpassthru.php