parse string like eval

Rayn

is there a way to parse a string like eval does? For example this code using eval

[php.net example]
Example 1. eval() example - simple text merge

<?php
$string = 'cup';
$name = 'coffee';
$str = 'This is a $string with my $name in it.';
echo $str. "\n";
eval ("\$str = \"$str\";");
echo $str. "\n";
?>

The above example will show:

This is a $string with my $name in it.
This is a cup with my coffee in it.
[/php.net example]

instead I would like to use my own function like

Example 2.

<?php
$string = 'cup';
$name = 'coffee';
$str = 'This is a $string with my $name in it.';
echo $str. "\n";
echo string_parser($str) . "\n";
?>

The above example will show:

This is a $string with my $name in it.
This is a cup with my coffee in it.

Thanks for your time
- Me

LordShryku

So you wanna do the same exact thing as eval, but not call it eval?

Rayn

correct

LordShryku

function fake_eval($code) {
   eval($code);
}

HalfaBee

Why not use double quotes.

$str = 'This is a $string with my $name in it.';
echo $str. "\n"; 
$str = "This is a $string with my $name in it.";
echo $str. "\n";

This is a $string with my $name in it.
This is a cup with my coffee in it.

HalfaBee

Rayn

because I am calling the data from a database so it really doesnt work like that I believe.

LordShryku: That is still using eval() though 😉

Let me say what I am trying to do again..

I want to make a function that will parse input like eval does, but without using eval itself.

HalfaBee

How about a function that uses str_replace to replace the $string

echo str_replace( '$string',$string,$db_string );

Weedpacket

Just variable interpolation, is it?

$text = 'this is a $string with my $name in it';
$string='cup';
$name='coffee';

$text = preg_replace('/(\$\\w+)/e', "$1", $text);
echo $text;

Rayn

Thank you. I have on more question.

I am using this within a function and getting all the used variables through a $GLOBALS loop, but when I run the code the $name output is blank.

$temp = 'Name: $name';
$name = 'dan';

function test($text) {

foreach ($GLOBALS as $key => $value) 
{ 
	$$key = $value;
	if ($$key) {
                $text = preg_replace('/(\$\w+)/e', "$1", $text);
	}
}

return $text;

}

echo test($temp); // Outputs Name:

If I echo $name in the function it prints the name, but doesnt work with the preg_replace. :o

Thanks for your time and help
- Rayn

HalfaBee

This could be a bit dangerous.

$GOLBALS has all the variables and you are doing a preg_replace on every one of them

This function is equivalent to this.

$temp = 'Name: $name';
$name = 'dan';

function test($text) {
    return "$test";
}

echo test($temp); // Outputs Name: