setlocale
If you've got a script that allows user file upload, and you want to prevent multiple uploads of the same file:
<?
session_start();
$isDuplicate = false;
if(isset($_FILES["filename"]["tmp_name"]) && file_exists($_FILES["filename"]["tmp_name"])) {
$fileHash = sha1_file($_FILES["filename"]["tmp_name"]);
if(!isset($_SESSION["check_filelist"])) {
$_SESSION["check_filelist"] = array($fileHash);
}
elseif(in_array($fileHash,$_SESSION["check_filelist"])) {
$isDuplicate = true;
}
else {
$_SESSION["check_filelist"][] = $fileHash;
}
if($isDuplicate) {
echo "You've already uploaded that file";
}
else{
// do some stuff
}
}
?>
sha1_file
(PHP 4 >= 4.3.0, PHP 5, PECL hash:1.1-1.3)
sha1_file — Υπολογίζει τον αριθμό sha1 hash ενός αρχείου
Περιγραφή
string sha1_file
( string $filename
[, bool $raw_output
] )
Υπολογίζει τον αριθμό sha1 hash του αρχείου filename χρησιμοποιώντας τον » US Secure Hash Algorithm 1, και τον επιστρέφει. Ο hash είναι ένας δεκαεξαδικός αριθμός 40 χαρακτήρων. Σε περίπτωση αποτυχίας επιστρέφεται η τιμή FALSE. Εάν η προαιρετική παράμετρος raw_output πάρει την τιμή TRUE, τότε επιστρέφεται μία περίληψη του sha1 σε μορφή raw binary και με μήκος 20 χαρακτήρων.
Note: Η προαιρετική παράμετρος raw_output προστέθηκε στην PHP 5.0.0 και η προκαθορισμένη τιμή της είναι FALSE
Ανατρέξτε επίσης στις: sha1(), crc32(), και md5_file()
add a note
User Contributed Notessha1_file
schiros at invisihosting dot com
06-Sep-2007 07:02
06-Sep-2007 07:02
admin at cmsrevolution dot com
04-Aug-2006 08:02
04-Aug-2006 08:02
checking the sha1 of the file. ideal for download scripts making sure the file the user is downloading is not currupt
by checking the sha1 key
<?php
$filename = './Path/To/Your/File.zip';
if (file_exists($filename)) {
echo"i see the file";
} else {
echo "recheck the link file maybe broken";
}
$file = sha1_file('./Path/To/Your/File.zip');
echo"<br>is file hash valid?";
echo"hash = add the hash here<br>";
echo"hash of file :";
print($file);
?>
gubatron at gmail dot com
10-Feb-2006 07:02
10-Feb-2006 07:02
P2P programs like LimeWire utilize sha1 to identify files. However they do it in base32. Here's an utility class if you want to write a Gnutella client in PHP5
/**
Utility base32 SHA1 class for PHP5
Copyright (C) 2006 Karl Magdsick (original author for Python)
Angel Leon (ported to PHP5)
Lime Wire LLC
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
class SHA1 {
static $BASE32_ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
/** Given a file it creates a magnetmix */
static function fileSHA1($file) {
$raw = sha1_file($file,true);
return SHA1::base32encode($raw);
} //fileSHA1
/** Takes raw input and converts it to base32 */
static function base32encode($input) {
$output = '';
$position = 0;
$storedData = 0;
$storedBitCount = 0;
$index = 0;
while ($index < strlen($input)) {
$storedData <<= 8;
$storedData += ord($input[$index]);
$storedBitCount += 8;
$index += 1;
//take as much data as possible out of storedData
while ($storedBitCount >= 5) {
$storedBitCount -= 5;
$output .= SHA1::$BASE32_ALPHABET[$storedData >> $storedBitCount];
$storedData &= ((1 << $storedBitCount) - 1);
}
} //while
//deal with leftover data
if ($storedBitCount > 0) {
$storedData <<= (5-$storedBitCount);
$output .= SHA1::$BASE32_ALPHABET[$storedData];
}
return $output;
} //base32encode
}