Check if files exist

crump

Hello,

I want to build a php form that uploads a zip folder that contains some static html files and a shared image folder. This part is done. Next, I need to compare the img src in the html files with the images in the image folder. If images exist don't do anything, else save unused images in a temp folder or delete.

Below is the code. I can extract images from the shared image folder and the relative image src from the html files but I don't know how to compare/check the two. Do I check the html file against the image folder or the other way around? Not sure what PHP functions to use(file_exist, getimagesize, curl, etc.). Any ideas?

//path to directory to scan
$dir = "path/to/image/directory";

//get all image files with a .jpg, .gif, .png extension.
$images = glob($dir . "*.{jpg,gif,png}", GLOB_BRACE);

//print images in image folder - for testing purpose spits out images/1.jpg, images/2.png, images/3.gif
foreach($images as $image)
{
echo 'images/'. basename($image) . '<br />';
}

//extract img src from html
$url="path/to/html";

$html = file_get_contents($url);
$dom = new DOMDocument();
$dom->loadHTML($html);

//echo image src - for testing purpose spits out images/1.jpg, images/2.png, images/3.gif
foreach ($dom->getElementsByTagName('img') as $img) {
echo $img->getAttribute('src'). '<br />';
}

johanafm

crump;11010905 wrote:
Hello,
If images exist don't do anything, else save unused images in a temp folder or delete.
…
Do I check the html file against the image folder or the other way around?

There are three possible senarios here. The image exist (as a file) and is used (in the html code), the image exists but isn't used and the image is used but does not exist. I'm not certain exactly what you wish to do from the above, but if you wish to handle all three possibilities you will need to do both, i.e. compare html file against image folder AND image folder against html.

The reasoning is simple: If you iterate over all the images in the html code and check if they exist as files, you will find any missing file. If you iterate over all the files and compare them to the images in the html code, you will find all unused images.

I posted code in this thread which deals with both scenarios. It's not for images, but the principles are the same.

crump

johanafm;11010911 wrote:
There are three possible senarios here. The image exist (as a file) and is used (in the html code), the image exists but isn't used and the image is used but does not exist. I'm not certain exactly what you wish to do from the above, but if you wish to handle all three possibilities you will need to do both, i.e. compare html file against image folder AND image folder against html.

The reasoning is simple: If you iterate over all the images in the html code and check if they exist as files, you will find any missing file. If you iterate over all the files and compare them to the images in the html code, you will find all unused images.

I posted code in this thread which deals with both scenarios. It's not for images, but the principles are the same.

Thanks for your reply. I'm only interested in finding images that exist in the image folder that aren't used in the html. Once I can extract the unused images I want to either delete now or save them in another folder to be deleted later. I don't care to find images that are used in the html. Multidimensional array is way over my head. Do you have a simple example? For example, what would I put in the new and old arrays? Thanks again!

crump

Hi,

I'm mostly interested in finding the images that exist in the image folder that aren't used in the html files. I don't need to find images that exist in both html and image folder. Re the multidimensional array that you suggested in a previous thread what do I put in the array if I don't know what the values are? Can you give me an example of how I would implement the array? Thanks!

Weedpacket

crump wrote:
I don't need to find images that exist in both html and image folder.

But if you had that list you could remove the files listed in it from the list of files in the image folder. What you have left would be what you're asking for.

Incidentally, if you get a list of files used in HTML documents, and a list of files in the image folder, [man]array_diff[/man] would allow you to subtract one from the other.

traq

of course, everything discussed so far would only find existing/non-existing/matching/non-matching image filenames (which may or may not represent the same images).

: )

crump

If I'm not comparing filenames to determine if images exist/match what should I be comparing then? I keep going back to using file_exist with fopen to find if a relative path exists. Didn't think to use array. I think I'm more confused now. Haha.

My initial thought was to check the relative img src path and see if it exists. But all I could do thus far was extract and echo the filenames in the html and image folder.

Can someone/anyone show me an example?

traq

If you are the only one that will ever upload files, then you'll probably be fine, as long as you pay attention. But if you have multiple users, it becomes much more likely that there will be a filename collision.

you could use [man]md5/man. compare the file checksums. something I've done before is to record image filenames, dimensions, format, etc. in a database, and then name the uploaded file with its checksum. That way, comparing filenames is an accurate indication as to whether it's the same image.

crump

Yes, I'm the only one uploading the files. This is just a project so I can learn PHP. I want to create a personal tool where I can isolate the 'unused' images and delete them so that I don't have a bunch of extra images in my folder. I tried a slightly different approach. What I did was extract images from html and image folder and put them arrays. Now I'm going to compare the two arrays with array_diff. But this code:

      $new_array = array_diff($h, $i);
      echo $new_array;

gives me 'array.' How would I use array_diff to compare? Thanks!

//path to directory to scan
$dir = "path/to/image/folder";

//get all image files with a .jpg, .gif, .png extension.
    $images = glob($dir . "*.{jpg,gif,png}", GLOB_BRACE);

     //print array from foreach loop
 $h = array();
     foreach($images as $k => $image)
     {		
	  echo 'images/'.basename($image), $h[$k] . '<br />';	
     }

  //get img src 
  $url="path/to/html/file";
  $html = file_get_contents($url);
      $dom = new DOMDocument();
      $dom->loadHTML($html);
      $imgs = $dom->getElementsByTagName('img');

  $i = array();
  foreach ($imgs as $j => $img) {
	echo $img->getAttribute('src'), $i[$j] . '<br />';			
       }

  //compare two arrays
  $new_array = array_diff($h, $i);
      echo $new;

crump

      $new_array = array_diff($h, $i);
      echo $new_array;

gives me 'array.' How would I use array_diff to compare? Thanks!

//path to directory to scan
$dir = "path/to/image/folder";

//get all image files with a .jpg, .gif, .png extension.
    $images = glob($dir . "*.{jpg,gif,png}", GLOB_BRACE);

     //print array from foreach loop
 $h = array();
     foreach($images as $k => $image)
     {		
	  echo 'images/'.basename($image), $h[$k] . '<br />';	
     }

  //get img src 
  $url="path/to/html/file";
  $html = file_get_contents($url);
      $dom = new DOMDocument();
      $dom->loadHTML($html);
      $imgs = $dom->getElementsByTagName('img');

  $i = array();
  foreach ($imgs as $j => $img) {
	echo $img->getAttribute('src'), $i[$j] . '<br />';			
       }

  //compare two arrays
  $new_array = array_diff($h, $i);
      echo $new;

crump

Arggghh, apparently I don't know how to use this thread either. Sorry for the duplicate reply.

traq

crump wrote:
Sorry for the duplicate reply.

you mean, the duplicate reply PLUS the apology reply? : )

// instead of
echo $new_array;

// use
print_r( $new_array );
// and see what happens  : )

crump

Hi,

I got the arrays, converted them to string and using pathinfo['basenames'] got the image names. Now I'm not sure how to do a string comparison.

What I have:

$str1 (a1.gif, a2.gif, a3.gif)
$str2 (a1.gif, a2.gif, a4.gif)
$str3 (a1.gif, a2.gif, a5.gif)
$str4 (a1.gif, a2.gif, a6.gif)

Desired result should be:

Matched: a1.gif, a2.gif
Non-matched: a3.gif, a4.gif, a5.gif, a6.gif

I tried the code below but it returned "matched" on all images including ones that don't match. Since $str1 are images from the image folder I want to use $str to compare against the other strings ($str1 to $str3, $str1 to $str2, etc). Any suggestions on how to do this? Thank you!

if(strcmp($str1, $str2)){
   echo 'matched';
   }else{
   echo 'no matched';
 };

Weedpacket

Use [man]array_diff[/man] to remove the elements of one array from another.

crump

I have two arrays. $array1 is from the image folder and $array2 is extracted from img src in an html file.

$array1
path/to/image/folder/a1.gif
path/to/image/folder/a2.gif
path/to/image/folder/a3.gif

$array2
image/a1.gif
image/a2.gif
image/a4.gif

Since they have different paths, I converted to string and only get basenames (a1.gif, a2.gif, etc)

Using if(array_diff($array1, $array2)) I should get:
not matched: a3.gif, a4.gif

But, I'm getting:
matched: a1.gif, a2.gif, a3.gif, a4.gif

What am I doing wrong?

traq

<?php
$array1 = array( 'a1.gif','a2.gif','a3.gif' );
$array2 = array( 'a1.gif','a2.gif','a4.gif' );
$result = array_merge( array_diff( $array1,$array2 ),array_diff( $array2,$array1 ) );
var_dump( $result );
// prints:
//    array(2) {
//      [0]=>
//      string(6) "a3.gif"
//      [1]=>
//      string(6) "a4.gif"
//    }

crump

It didn't work. :-(

This is my code for getting images from folder:

/*** get images in image folder ***/
$dir = "path/to/image/folder"; 
$imgs = glob($dir . "*.{jpg,gif,png}", GLOB_BRACE);

foreach($imgs as $img){
     $arr1[] = $img;
     $str1 = implode($arr1); // convert to string
     $filePath = pathinfo($str1); // get pathinfo
     echo ($filePath['basename']) . '<br />'; 
}; 
//converts path/to/image/folder/a1.gif  to  a1.gif

And code for getting images from html img src:

/*** get img src in html ***/
$path = '/path/to/.*html';
$dom = new DOMDocument;
$dom->preserveWhiteSpace = false;
@$dom->loadHTMLFile($path);
$images = $dom->getElementsByTagName('img'); 

foreach ($images as $image) {
     $arr2[]=$image->getAttribute('src');
     $str2 = implode($arr2);  // convert to string
     $filePath = pathinfo($str2);  // get pathinfo
};
//Result:  converts <img src="images/a2.gif" /> to a2.gif

This returns matched on all images.

$array1 = array($str1);
$array2 = array($str2);
$result = array_merge( array_diff( $array1,$array2 ),array_diff( $array2,$array1 ) );
var_dump( $result );

Weedpacket

That's because, instead of comparing arrays of filenames, you're comparing filenames-mashed-together-into-a-string-and-then-put-into-an-array.

If you want to compare arrays, compare arrays. Don't turn them into strings first. If you do that, they're not arrays any more.

crump

How would I compare these two arrays:

foo/bar/a1.jpg to foo/a1.jpg

Wouldn't I always get a no match even though a1.jpg does exist despite having different paths?

Confused.

bradgrafelman

crump;11011419 wrote:
How would I compare these two arrays:

foo/bar/a1.jpg to foo/a1.jpg

What arrays? You've only shown us two pieces of data which are, I'm presuming, file paths. File paths are most commonly expressed as strings, so... what arrays?

crump;11011419 wrote:
Wouldn't I always get a no match even though a1.jpg does exist despite having different paths?

Depends on what you mean by "match", i.e. how the comparison is being done. If you're doing a straight string comparison, then no, of course those won't match.