execute a string?

ristuart

Hi,

I have been trying to think of different ways round various problems in the structure of a site I am working on for some time now, and this would be very useful if it is possible.

Is there a function (or some other way) to execute a string in PHP? So if I have a variable which contains some PHP code, can I execute that code?

The only thing I have thought of is writing it to a file, then including/requring the file. This would not be at all ideal, and I am not going to do that!

I am fairly sure that simply echoing the variable does not run the PHP, although come to think of it I am not sure if I tested that or not. I am sure it wouldn't though.

Can anyone help? Thanks very much for your time,

ristuart

Weedpacket

[man]eval[/man]

khaine

Not 100% sure on the php in a string do you mean that you have a string which reads

$varname="hello ".$name;

you can output the result of this string using echo. i.e.

echo $varname;

This would give you the output to the browser window. If you mean you have say a file access routine in a variable. First question is why? You can execute php like a shell command but only if php is installed to run that way.

Mark.

ristuart

Originally posted by Weedpacket
[man]eval[/man]

Thanks, that's just what I need 🙂. I had looked in the manual before but obviously I missed it!

Mark - I meant if I have some actual PHP code stored in a string and I want to evaluate it as PHP code. The reason is that the content for a website I am working on is coming from a database, and it would be useful to be allowed to have PHP in some of the pages themselves. The content is loaded from the database into a variable - hopefully you see what I mean? If not, the manual actually explains it quite well.

From PHP Manual:
eval() evaluates the string given in code_str as PHP code. Among other things, this can be useful for storing code in a database text field for later execution.

Thanks again,
Richard

Weedpacket

This is exactly what I've been using on one project, which has involved a development server serving multiple independent sites simultaneously. For maintenance purposes the entire site is to run out of the dbms, with only a couple of config files to distinguish between them.

Each site has its own database, and also calls on a single database common to all of them that contains our code libraries, page templates, the structure of each site, and all that sort of stuff. Needless to say, it makes heavy use of eval(), because every page gets written from scratch and executed by a common development engine (written in PHP) every time it's needed. (Further needless to say, this is only while a site's under development!)