Partial output of random numbers string

[Deleted user]

First of all I'd like to disclose that I'm neither professional nor hobbyist programmer/coder. Just an aspiring end user :)

I have the following code:

<?php
$factory = new RandomLib\Factory;
$generator = $factory->getMediumStrengthGenerator();
$genoutext = $generator->generateString(64, '!"#$%&\'\\(\\)\*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~');
?>

<?php echo $genoutext; ?>
<br />
<?php echo mb_strlen($genoutext); ?>

The issue is that, sometimes, the output random string (echo $genoutext;) will have fewer than 64 characters in it, I've seen as low as 2, and yet at all times mb_strlen output will show the number 64.

I suppose, perhaps, I may not really understand how mb_strlen is supposed to work, but what could be the cause of the generator outputting less random data then it is specified? Just a guess, could it be that sometimes not enough entropy is available on my shared hosting account? In case if that might be so, is there a way to delay the output of random data until enough entropy is accessible to generate the full 64 character random string?

Thank you!

[ircmaxell]

That shouldn't be possible... It should literally always return 64 characters, or infinite loop trying to (specifically, this loop: https://github.com/ircmaxell/RandomLib/blob/master/lib/RandomLib/Generator.php#L165 )

Hang on, when you say "echo", do you mean in the middle of a webpage? Because the presence of < or " characters may wind up hiding part of the output into the source of the page. Or perhaps your template engine is stripping them. Or something of that fact. If mb_strlen (or strlen) reports 64 characters, it's being correctly generated (indeed, otherwise it would have to infinitely loop).

I would look elsewhere in your stack to see if something else is messing with the string prior to output (or if it's just being hidden by the browser)...

[Deleted user]

Yes, I'm trying to output random string on a webpage.

Indeed, I have escaped some special characters, but other characters have been successfully forgotten by me.

Thank you so much for pointing this out, and thank you for your excellent software creations!