PHP Tutorial - PHP sha1_file() Function






Definition

The sha1_file() function calculates the SHA-1 hash of a file.

Syntax

PHP sha1_file() Function has the following syntax.

sha1_file(file,raw)

Parameter

ParameterIs RequiredDescription
fileRequired.The file to be calculated
rawOptional.A boolean value that specifies hex or binary output format:

Possible values for raw.

  • TRUE - Raw 20 character binary format
  • FALSE - Default. 40 character hex number




Return

PHP sha1_file() Function Returns the calculated SHA-1 hash on success, or FALSE on failure

Example 1

Calculate the SHA-1 hash of the text file "test.txt":


<?php
$filename = "test.txt";
$sha1file = sha1_file($filename);
echo $sha1file;
?>

Example 2

Store the SHA-1 hash of "test.txt" in a file and test if "test.txt" has been changed (that is if the SHA-1 hash has been changed):


<?php//from   w  w w  .ja  va 2s  .  c om
$sha1file = sha1_file("test.txt");
file_put_contents("sha1file.txt",$sha1file);

$sha1file = file_get_contents("sha1file.txt");
if (sha1_file("test.txt") == $sha1file){
  echo "The file is ok.";
}else{
  echo "The file has been changed.";
}
?>