checking file extensions. How can I change this?

Sam Granger · 09-29-2007, 08:07 AM

Code:

	function checkFileExtentions(form){
		if(check_file_extentions == false){ return false; }
		var re = /(\.php)|(\.sh)$/i;
		if(form['filename'].value != ""){
			if(form['filename'].value.match(re)){
				var string = form['filename'].value;
				var num_of_last_slash = string.lastIndexOf("\\");
				if(num_of_last_slash < 1){ num_of_last_slash = string.lastIndexOf("/"); }
				var file_name = string.slice(num_of_last_slash + 1, string.length);
				var file_extention = file_name.slice(file_name.indexOf(".")).toLowerCase(); 
				alert('Sorry, uploading a file with the extention "' + file_extention + '" is not allowed.');
				return true;
			}
		}
		return false;
	}

I have the following js code. At the moment, it warns me if I want to upload a php file. How can I make it warn me for all file extensions, with the exception of .jpg? :confused:

mortisimus · 10-01-2007, 02:28 PM

Looks like it will warn you every time. I'm no good at javascript but maybe do a check for something like:

if (file ext. doesn't equal jpg){
alert("error!");
}
else
{
//carry on with upload or whatever...
}

sorry but I do not know the right js code to put in...

Salathe · 10-01-2007, 03:05 PM

Code:

// Returns true if the extension is invalid
function checkFileExtentions(form)
{
	if (check_file_extentions == false)
	{
		return false;
	}
	
	// Regex of valid extensions
	var re = /\.(jpg|jpeg|png|gif|bmp)$/i
	
	// If we have a filename to check and it is invalid
	if (form['filename'].value != '' && !form['filename'].value.match(re))
	{
		var name = form['filename'].value;
		var ext  = name.substr(name.lastIndexOf('.')+1).toLowerCase();
		alert('Sorry, uploading a file with the extention "' + ext + '" is not allowed.');
		return true;
	}
	
	return false;
}

Sam Granger · 10-03-2007, 03:31 PM

Thanks Salathe! That code of yours worked like a dream!

Salathe · 10-03-2007, 03:32 PM

You're most welcome, I'm here to help. :)

Geert · 12-09-2007, 04:51 PM

The "jpg" and "jpeg" extensions can be merged into one alternation option, which should be faster.

Code:

/\.(jpe?g|png|gif|bmp)$/i

Also, since you're not using the captured parentheses, make them non-capturing, which should be faster.

Code:

/\.(?:jpe?g|png|gif|bmp)$/i