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I am new to php and would like to ask you for some help returning an unique result from file_get_contents(). The reason is I want to give each photo an unique name, so that later it will be possible to delete just one of them and not all.

$file =addslashes(file_get_contents($_FILES['image']['tmp_name'][$key]));

Unfortunately time() and microtime() doesn't help in this situation.

cyberspacelogin
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  • What do you mean by *unique result*? The function just returns contents of file, so if the file is not modified, it will never be unique. –  Jul 08 '17 at 19:03
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    `The reason is I want to give each photo an unique name`:- `file_get_contents()` is not going to do that.it will give you the content of the file – Alive to die - Anant Jul 08 '17 at 19:05
  • thank you, but then how can I store the photos in table column type longblob with unique name? I couldn't store and print the photos if I use varchar(with unique name) – cyberspacelogin Jul 08 '17 at 19:12
  • Longblob stores __file contents__, it does not store filename. – u_mulder Jul 08 '17 at 19:15
  • At te time of saving image to folder and saving it's path to db column,add `microtime()` in the `$_FILES`name of the file. – Alive to die - Anant Jul 08 '17 at 19:18
  • I 've tried to add it everywhere.. now tried again after [$key] and received this: "Warning: file_get_contents(C:\xampp\tmp\php737B.tmp0.96288300 1499541779): failed to open stream:No such file or directory in C:\xampp\htdocs\HW_bshop\products.php on line 33" – cyberspacelogin Jul 08 '17 at 19:23
  • What if I use time() . $_FILES['image']['name'][$key] to store the path in DB under column VARCHAR, how should then retrieve and print the photos from DB – cyberspacelogin Jul 08 '17 at 19:29

2 Answers2

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Maybe this will help you: http://php.net/manual/en/function.uniqid.php

uniqid();

$imageName = $imageName . '_' . uniqid();

Bluesky
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Why not just generate the SHA-1 of the content and use that as the file name (sort of like how git stores objects in a repository's loose object database)? I typically don't like to insert blobs into the RDBMS; it's a little clunky and you have to make sure the blob field has enough space for the kind of file sizes you're expecting to work with. Plus, the filesystem is optimized to handle, well, files. So it makes sense to keep a special directory on the server to which the Web server has write access. Then you write the files there and store references to them in the database. Here's an example:

// Read the contents of the file and create a SHA-1 hash signature.
$tmpPath = $_FILES['image']['tmp_name'];
$blob = file_get_contents($tmpPath);
$name = sha1($blob) . '.img'; // e.g. b99c6e26c3775fca9918ad614b7be7fe4fd7bee3.img

// Save the file to your server somewhere.
$dstPath = "/path/to/imgdb/$name";
move_uploaded_file($tmpPath,$dstPath);

// TODO: insert reference (i.e. $name) into database somehow...

And yes, researches have broken SHA-1, but you could easily write some safeguards against that if you're paranoid enough (e.g. check for an existing upload with the same hash; it the content differs, just mutate/append to the name a little to change it). You aren't identifying the image on the backend by its content: you just need a unique name. Once you have that, you just look it up from the DB to figure out the file path on disk corresponding to the actual image data.

If you expect the image files to be pretty large, you could limit how much you read into memory using the 4th parameter to file_get_contents().

Roger Gee
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