[SOLVED] How to restrict image upload file names

[RyanSF07]

Hello,

 

I have an image upload form -- how do I restrict file names to contain letters, numbers, hyphens, dashes, and/or periods only, and restrict also the length of the file name? That is, if the file uploaded has accent marks, foreign characters, etc, an error message will trigger (file names cannot contain special characters) and if too long trigger an error (file names must be no longer than 40 characters)?

 

In my validation script I have this kind of set up where $fieldname is the variable that would need to be checked:

 

	if (getimagesize($_FILES[$fieldname]['tmp_name'])){
	$h = TRUE;
} else {
	$h = FALSE;
	$content .= "<p>Only GIF, JPEG, and PNG image uploads are allowed. Max file size 50K.</p>\n";
}

 

Thank you for your help!

[RyanSF07]

How do I get the name of the file and then apply a regular expression like this ^[a-zA-Z0-9_\s-]+$ to it?

 

thanks

[RyanSF07]

I'm trying this -- yet the error is not being triggered -- any ideas?

 

if(preg_match('^[a-zA-Z0-9_\s-]+$', $fieldname) ) {
	$k = TRUE;
} else {
	$k = FALSE;
	echo "<p>File Name :: Letters and numbers only please. Space, underscore, and hyphen characters also supported.</p>\n";
}

[RyanSF07]

OK. Got this to work

 

Can I add to the reg ex to limit the number characters in the $filename?

 

thanks!

[Psycho]

Try changing the plus sign to the min and max number of characters you want to allow - encased in curly braces. I would assume the minimum would be 5 characters: a single letter file name, the period and a three character extension. So, you would use "{5,64}" to allow 5 to 64 characters.

 

Example:

preg_match('^[a-zA-Z0-9_s-]{5, 64}$', $fieldname)

[RyanSF07]

I got back to this post too late -- All is working now. Can you check this though?

 

I added "allow a dot" to the reg ex, but don't mean for the dot to represent any character -- did I do that right?

 

Also went with a limit variable to limit the length -- yours is much cleaner though...

 

$pic=$now++.'-'.$_FILES[$fieldname]['name'];

if(preg_match('#^[a-z0-9_\s-\.]*$#i', $pic) ) {
	$k = TRUE;
} else {
	$k = FALSE;
	$content .= "<p>There is a problem with the image filename. Letters and numbers only please. Space, underscore, and hyphen characters also supported.</p>\n";
}


$desc_length = strlen($pic);
        $limit = 40; 
        if ($desc_length <= $limit) {
        $l = TRUE;
} else {
	$l = FALSE;
	$content .= "<p>There is a problem with the image filename -- It's too long. Make it shorter please.</p>\n";
}