ereg_replace replacement

[dataxa]

My aim is to replace @@something@@ parts of the texts with the same name of variables defined before ($something)

 

<?php

$rep1 = "water";

$rep2 = "aquarium";

$text = "Fish swims in a @@rep1@@. Fish lives in a @@rep2@@.";

 

echo ereg_replace("(@{2})(.{1,10})(@{2})",${"\\2"},$text);

echo "\n";

echo $text;

?>

 

script says:undefined variable '\2' in line 6, as look like construction ${} will take everything inside it between the quotas as string and one slash allows second slash to be displayed

 

as you can see actually \\2 is a second part of string what should be replaced by $rep1 or $rep2

 

I hope somebody can help me.

[btherl]

You definitely can't do it like that.  There's bizarre extensions in perl which allow you to do that within a regexp, but I would do it outside to maintain sanity.

 

The simplest and cleanest way I can think of is to use one ereg_replace() for each variable you are replacing.  Then there's no need to be so flexible with the regexp.

 

If you're planning to do some heavy duty replacing (too much to use individual ereg_replace()), I would use Smarty or another existing template system.

 

And finally, preg_replace() is faster

[dataxa]

if i just put this:

 

echo ereg_replace("(@{2})(.{1,10})(@{2})","\\2",$text);

 

then i get:

 

Fish swims in a rep1 Fish lives in a rep2

 

so it works, just i dont know how i can tell php to accept them as variables

[btherl]

Aha, it is possible.  You need this function:

 

http://sg.php.net/manual/en/function.preg-replace-callback.php

 

Your callback will need to see which string was matched (eg rep1, rep2) and return the appropriate variable.  It could be as simple as:

 

function my_callback($matches) {
  return $$matches[0];
}

 

The variables must be available within my_callback(), so you may need to declare them as global.  Or you can return $_GLOBALS[$matches[0]] instead.  Then

 

echo preg_replace_callback("/(@{2})(.{1,10})(@{2})/","my_callback",$text);

 

No guarantees on this untested code.  Note that to use preg instead of ereg, you usually just need to add "/" to the start and end of the pattern, and escape any "/" which appears within the pattern.

[dataxa]

$text = "Fish swims in a @@rep1@@. Fish lives in a @@rep2@@.";

 

function callback($value) {

$rep1 = "water";

$rep2 = "aquarium";

return $$value;

}

 

echo preg_replace("/(@{2})(.{1,10})(@{2})/",callback("\\2"),$text);

echo "\n";

echo $text;

 

It still takes \\2 as \2. Somt time i got idea to use eval(), but it didnt work as well.

I mean:

preg_replace("/(@{2})(.{1,10})(@{2})/",eval("$\\2"),$text);

[effigy]

An array would be better, but here you go:

 

<pre>
<?php
$rep1 = "water";
$rep2 = "aquarium";
$text = "Fish swims in a @@rep1@@. Fish lives in a @@rep2@@.";
echo preg_replace("/@@([^@]{1,10})@@/e", '$\1', $text);
?>
</pre>