hash_file

(PHP 5 >= 5.1.2, PECL hash:1.1-1.5)

hash_file — Generate a hash value using the contents of a given file

Beschreibung

string hash_file ( string $algo , string $filename [, bool $raw_output ] )

Parameter-Liste

algo: Name of selected hashing algorithm (i.e. "md5", "sha256", "haval160,4", etc..)
filename: URL describing location of file to be hashed; Supports fopen wrappers.
raw_output: When set to TRUE, outputs raw binary data. Default value (FALSE) outputs lowercase hexits.

Rückgabewerte

Returns a string containing the calculated message digest as lowercase hexits unless raw_output is set to true in which case the raw binary representation of the message digest is returned.

Beispiele

Beispiel #1 Using hash_file()


<?php
/* Create a file to calculate hash of */
file_put_contents('example.txt', 'The quick brown fox jumped over the lazy dog.');

echo hash_file('md5', 'example.txt');
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

5c6ffbdd40d9556b73a21e63c3e0e904

Siehe auch

add a note User Contributed Notes
hash_file

allaryin at gmail dot com
24-Jul-2008 12:16


For those who are wondering, there appears to be no fundamental difference between hash_file('md5')/hash_file('sha1') and md5_file()/sha1_file(). They produce identical output and have comparable performance.



There is, however, a difference between hash_file('crc32') and something silly like crc32(file_get_contents()).



crc32(file_get_contents())'s results are most similar to those of hash_file('crc32b'), just with the octets reversed:



<?php

$fname = "something.png";



$hash = hash_file( 'crc32', $fname );

echo "crc32  = $hash\n";



$hash = hash_file( 'crc32b', $fname );

echo "crc32b = $hash\n";



$hash = sprintf("%x",crc32(file_get_contents($fname)));

echo "manual = $hash\n";

?>



crc32  = f41d7f4e

crc32b = 7dafbba4

manual = a4bbaf7d

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hash_final

hash_copy

Last updated: Fri, 05 Sep 2008