What is wrong with this PHP file rename code? - php

Question

The following code is meant to iterate through a directory of images and rename them.
I had it working well, but what I would like to add is a 'static' token at the beginning of the file that once renamed, it will then in future ignore.
For example, let's say that we have a directory of 100 files.
The first 20 of which go by the name "image-JTzkT1RYWnCqd3m1VXYcmfZ2nhMOCCunucvRhuaR5.jpg"
The last 80 go by the name "FejVQ881qPO5t92KmItkNYpny.jpg" where this could be absolutely anything.
I would like to ignore the files that have already been renamed (denoted by the 'image-" at the beginning of the file name)
How can I do this?
<?php
function crypto_rand_secure($min, $max) {
$range = $max - $min;
if ($range < 0) return $min; // not so random...
$log = log($range, 2);
$bytes = (int) ($log / 8) + 1; // length in bytes
$bits = (int) $log + 1; // length in bits
$filter = (int) (1 << $bits) - 1; // set all lower bits to 1
do {
$rnd = hexdec(bin2hex(openssl_random_pseudo_bytes($bytes)));
$rnd = $rnd & $filter; // discard irrelevant bits
} while ($rnd >= $range);
return $min + $rnd;
}
function getToken($length){
$token = "";
$codeAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
$codeAlphabet.= "abcdefghijklmnopqrstuvwxyz";
$codeAlphabet.= "0123456789";
for($i=0;$i<$length;$i++){
$token .= $codeAlphabet[crypto_rand_secure(0,strlen($codeAlphabet))];
}
return $token;
}
$dir = "/path/to/images";
if ( $handle = opendir ( $dir)) {
echo "Directory Handle = $handles<br />" ;
echo "Files: <br />" ;
while ( false !== ($file = readdir($handle))) {
if ( $file != "." && $file != ".." ) {
$isdir = is_dir ( $file ) ;
if ( $isdir == "1" ) {} // if its a directory do nothing
else {
$file_array[] = "$file" ; // get all the file names and put them in an array
//echo "$file<br />" ;
} // closes else
} // closes directory check
} // closes while
} // closes opendir
//Lets go through the array
$arr_count = count( $file_array ) ; // find out how many files we have found so we can initiliase the counter
for ( $counter=1; $counter<$arr_count; $counter++ ) {
echo "Array = $file_array[$counter] - " ; // tell me how many files there are
//$new = str_replace ( "C", "CIMG", $file_array[$counter] ) ; // now create the new file name
$new =getToken(50);
//if (substr($file_array[$counter]), 0, 3) == "gallery_image")
//{
//}
//else
//{
$ren = rename ( "$dir/$file_array[$counter]" , "image-$dir/$new.jpg" ) ; // now do the actual file rename
echo "$new<br />" ; // print out the new file name
//}
}
closedir ( $handle ) ;
?>

Answer 1

It seems like you're doing a lot of unnecessary work for something that should be quite trivial.
As far as I understand you want to get a list of the files from a directory and rename all of the ones not already pre-pended with image-.
You can do that with the following piece of code:
$dir = "/path/to/dir/"; //Trailing slash is necessary or you would have to change $dir.$newname to $dir.'/'.$newname further down the code
if(is_dir($dir)){
$dirHandle = opendir($dir);
while($file = readdir($dirHandle)){
if(is_file($dir.$file) === TRUE){
if(strpos($file, 'image-') === 0)
continue; //Skip if the image- is apready prepended
while(TRUE){
$cryptname = md5(mt_rand(1,10000).$file.mt_rand(1,10000)); //Create random string
$newname = 'image-'.$cryptname.'.jpg'; //Compile new file name
if(is_file($dir.$newname) === FALSE) //Check file name doesn't exist
break; //Exit loop if it doesn't
}
rename($dir.$file, $dir.$newname); //Rename file with new name
}
}
}
If you want to use your own function then you can the change the line:
$cryptname = md5(mt_rand(1,10000).$file.mt_rand(1,10000));
To use your function instead of md5. Like:
$cryptname = getToken(50);
I suggest that you should also check that the file name doesn't already exist otherwise - unlikely as it may be - you run the risk of overwriting files.
/images/ vs ./images/
Firstly, when dealing with the web you have to understand that there are effectively two root directories.
The web root and the document root. Take the example url http://www.mysite.com/images/myimage.jpg as far as the web root is concerned the path name is /images/myimage.jpg however, from php you have yo use the document root which would actually be something like: /home/mysite/pubic_html/images/myimage.jpg
So when you type / in php it thinks that you mean the directory which home is located in.
./images/ works because the ./ means this directory i.e. the one that the script/php is in.
In your case you probably have a file structure like:
>/
>home
>public_html
>images
image-243.jpg
image-243.jpg
index.php
So because index.php is in the same folder as images: ./images/ is equal to /home/public_html/images/. / on the other hand means the parent directory of home which has no images folder let alone the one you're targeting.
If you're more used to windows think of it like this: in php / means the document root directory (on windows that would be something like C:\).

Answer 2

You have the 'image-' in front of the directory portion of your file name:
$ren = rename ( "$dir/$file_array[$counter]" , "image-$dir/$new.jpg" )
should be
$ren = rename ( "$dir/$file_array[$counter]" , "$dir/image-$new.jpg" )