Generate file name from SHA hash

Question

I want to use the output of a SHA hash to generate a filename. Any recommended way to do that? I tried Base64 encoding, but for some input that results in the filename containing forward slashes. Obviously I would prefer a method whose output will never contain characters reserved by file systems. Converting each byte to a two-digit hex number would work, but something that produces shorter output would be preferable.

Answer 1

You can use this

    function getfilename(){

   mt_srand((double)microtime()*10000);
   $token=mt_rand(1, mt_getrandmax());
   $uid=uniqid(md5($token),true);   
   if($uid!=false && $uid!='' && $uid !=NULL){ return $filename =sha1($uid);}   
    }

    //create file name
    $filename=getfilename();
    $filename = substr($filename, 0, 10);

The above code uses the current system time to generate the File Name and also uses mt_rand and MD5 so as to create a unique file name every time the code is run. The final filename is 10 characters, and you can adjust it to whatever number of characters you want.

Answer 2

You could use Base32

It only uses alpha and numeric characters.