How to Identify a File is image or not in PHP

Question

I have tried with getimagesize() , finfo and getting Mime type function. But I have noticed we can not trust on these function as I observed it's fails in my case for some image files. Do we have any better way to identify a file is image or not. Use case : I have one file with php code inside it. I have saved this file with some image extension. Now I want to block this file from getting uploaded.

Possible duplicate of [uploaded file type check by PHP](http://stackoverflow.com/questions/6755192/uploaded-file-type-check-by-php) — , Dec 22 '16 at 05:55

score 0 · Answer 1 · answered Dec 22 '16 at 05:56

0

Try php's inbuilt method to check image type,

int exif_imagetype ( string $filename )

This method returns false if file is not a valid image otherwise will return an Integer pointing to the type of image.

Also it throws a notice. So you may do something like this.

if(@exif_imagetype($file)){
     //Valid Image
} else {
     // Invalid
}

answered Dec 22 '16 at 05:56

anwerj

2,386
2
17
36

I tried this but if you save a file contains some script with some image extension then also it's returns valid image – Harish Yadav Dec 23 '16 at 10:22
it should not, can you paste the content of file. – anwerj Dec 23 '16 at 11:28
looking forward to see what file saved as image extension will return valid image as well. I've tried several forms and it all returns false if it's invalid – Someone Special Oct 20 '18 at 04:11

score 0 · Answer 2 · edited May 23 '17 at 11:59

0

i think you should take a look over the

mime_content_type

or

Fileinfo

of

system("file -bi $uploadedfile")

see more detail view over the below post

How to check file types of uploaded files in PHP?

edited May 23 '17 at 11:59

Community

1
1

answered Dec 22 '16 at 05:57

Anand thakkar

479
3
8

score 0 · Answer 3 · answered Dec 22 '16 at 07:28

You can try this below code:

function is_image($path)
{
    $a = getimagesize($path);
    $image_type = $a[2];

    if(in_array($image_type , array(IMAGETYPE_GIF , IMAGETYPE_JPEG 
    ,IMAGETYPE_PNG , IMAGETYPE_BMP)))
    {
        return true;
    }
    return false;
}

score 0 · Answer 4 · answered Dec 23 '16 at 11:59

0

If your server is running on Linux you should execute file:

$mime = exec("file $tmpFilePath -z -b --mime-type");

This will define mime type correctly

answered Dec 23 '16 at 11:59

alvery

1,863
2
15
35

How to Identify a File is image or not in PHP

4 Answers4