PHP string md5_file() Function

PHP string md5_file() function is in-built important function. It is used to calculate the MD5 hash of a file. It uses the RSA Data Security. It returns the md5 hash on success, or FALSE on failure.

Syntax:

Parameter	Description	Required/Optional
File	Specify the file to be calculated.	Required
Raw	Specify the Boolean hex or binary format. TRUE - Raw 16 character binary format. FALSE - It is default and 32 character hex number.	Optional

Example 1

Save it: "test.txt" file and past it "Hello PHP" string inside the file.

<?php
$filename = "test.txt";
$md5file = md5_file($filename);
echo $md5file;
?>

Output:

c540ce201d398a7d275c6e0c669097f3

Example 2

We can store the MD5 hash of "test.txt" in a file:

<?php
$file = md5_file("test.txt");
file_put_contents("md5file.txt",$file);
?>

We can test if "test.txt" has been changed (if the MD5 hash has been changed):

<?php
$file = file_get_contents("md5file.txt");
if (md5_file("test.txt") == $file){
  echo "The file is ok.";
  }
else{
  echo "The file has been changed.";
  }
?>

Output: