scriptygoddess

1 | Jennifer

February 9th, 2003 at 1:24 pm

I once read a book about how to be a good "manager" and one of the first rules was to hire people who were "better than you". Based on this post, I think I've done just that by adding you! LOL! I don't want to bug the hell out of you – but I'd love it if you could give me a better explanation of all that.

Question 1) "ob_start() causes php to begin caching output rather than sending it to the browser"
What type of output do you mean? The only thing I would think that would be sent to the browser would be anything specifically in an "echo" or "print" (or would your "stuff, more stuff, etc." also be "cached")

Question 2) "$normal_text = ob_get_contents();"
Is that just taking whatever would have been output to the screen inside the variable "$normal_text"? (ie. "stuff, more stuff, etc.")

Question 3) "eval("?>" . $entry_text . "<?php ");"
I don't really get the eval() function. From what I read in the PHP manual – it looks like you put PHP code inside eval()… so in your case, $entry_text has some php code in it (WITH the <? ?> which is why I'm guessing you have the ?> and <? around entry_text) – and by putting it inside eval() it will actually EXECUTE that code… ie…
$entry_text = "<? echo 'hello'; ?>";
if you just did:
echo $entry_text;
you'd see this:
<? echo 'hello'; ?>
but if by doing eval($entry_text);
it would render
hello
however – (here's my question finally) eval doesn't return anything – is that why you need the ob_start, ob_get_contents… is that what actually grabs the "result" of eval()?

2 | adam

February 9th, 2003 at 4:05 pm

Question 1: It caches all output, even that which isn't generated by print and echo. I put together a little test that starts content buffering at the top of the page, fetches the source of my main page, and replaces < and %gt;, and puts the whole thing within a <pre> tag.

<?
ob_start();
>?

<? include("http://www.gessaman.com/index.php");>?

<?
$page = ob_get_contents();
ob_end_clean();

$page = str_replace(">" , "&gt;", $page);
$page = str_replace("<" , "&lt;", $page);
$page = ereg_replace("\n", "\r\n", $page);
header("Content-Type: text/html");
print "<pre>" . $page . "</pre>";
?>

Question 2: Exactly.

Question 3: See this explaination for the odd use of eval("?>" . $entry_text . "&lt?php "); Basically, because eval() processes any string as if it were code, you need to trick it into not attempting to execute everything that is outside of <? and ?> If it tries, it just spits error after error.

As far as needing to control the buffer to grab the output of eval(), you're absolutely right. Otherwise, it would simply output whatever print/echo statements you had in your code where-ever you invoked eval().

One side note on controlling the buffer: It appears that if there are errors in your php, the buffering is turned off and the error is dumped immediately, so remember to suppress errors @function() or code flawlessly. *grin*

3 | Jennifer

February 9th, 2003 at 9:38 pm

Cool – I think I have a better understanding. I think its one of those things, that I probably won't completely get until I have a project that uses it.. but at least I understand it enough to know it exists so when I hit the need, I'll know where to start. Thanks!!