Will this work?

[DavH27]

In this topic I'm gonna throw a load of questions at the people who know some PHP to find out a few little things that has been bugging me. I ask them here as I do not know where to find the answers elsewhere.

The first question is:
Can I use a variable to store some valid php code, much like a function? I know I can use a function and be done with it but I might need to do this for some reason (who knows?!) E.G.:

PHP Code:

<?php
$Print_hello = "echo (\"Hello, World!\");"

$Print_hello

[sde]

nope. seems like it would make things more complicated too. there is not time i think you would need that over calling an echo or custom function.

[idx]

The first thing that pops to mind is maybe you store some php code in a db then need to retreive and execute it.

See the eval function. (lol, and oddly enough db storage of php code is the first example.)

-r

[sde]

i stand corrected, this code works:

PHP Code:

<?
$str = "print('hello world');";
eval($str);
?>

[DavH27]

Can I refer to code in a database without having to use eval() ?
I've read in the php manual that it takes the page twice as long to show because it has to write and recompile twice.

Also can I use the usual within the .php doc?:

<!--#include file="SomePHPcode.txt" -->

I would test it out myself but I've yet to set up my local Apache server.

[idx]

No, (AFAIK) you have to first retreive the code from the DB [as a string], then use eval() to actually execute it.

The SSI might work, but it has nothing to do with PHP. PHP would just ignore it, pass it through and leave it to apache to process.

If you wanted to include (print) the contents of a file in PHP:

PHP Code:

readfile('SomePHPCode.txt'); 


...but to actually execute the code within that file:

PHP Code:

require 'SomePHPCode.txt';

// or
require_once 'SomePHPCode.txt'; 


See the docs on require
and include

-r