PHP ftruncate() Function Usage and Example

PHP Filesystem Reference Manual

The ftruncate() function can truncate the opened file to the specified length and can return true on success, and false on failure.

Syntax

bool ftruncate ( resource $handle , int $size )

This function can obtain a file pointer, process the file, and truncate its length to size.

Online Example

<?php
　　　//Check file size
　　　echo filesize("/PhpProject/sample.txt");
　　　echo "\n";
　　　$file = fopen("/PhpProject/sample.txt", "a+");
　　　
　　　ftruncate($file,　100);
　　　fclose($file);
　　　
　　　//Clear cache and check file size again
　　　clearstatcache();
　　　
　　　echo filesize("/PhpProject/sample.txt");
?>

Output Result

49
100

PHP Filesystem Reference Manual