regex/preg_replace

[sethadam1]

Help!

I want to scroll through a long string and do a series of replaces, like this:

replace [%main%] with $main
replace [%columnA%] with $columnA

can I do this with preg_replace()? Will it swap in the value of the variable $main or will it put the literal characters $main? I want the variable value for a template (no, I can't use Smarty).

Something like:

preg_replace("/[%[a-z0-9]+%]/,$$0,$string);

Can someone help me with that regex?

[sidney]

3 examples take your pick

//example 1
$txt="replace [%main%] with \$main 
replace [%columnA%] with \$columnA 
";
$array=array('main'=>"replace1",'columnA'=>"replace2");
foreach($array as $key => $val)
	{
	$txt=str_replace("[%".$key."%]",$val,$txt);
	}
echo $txt."<br>";

// example 2
$txt="replace [%main%] with \$main 
replace [%columnA%] with \$columnA 
";
$array2=array('main','columnA');
$main="replace3";
$columnA="replace4";
foreach($array2 as $val)
	{
	$txt=str_replace("[%".$val."%]",$$val,$txt);
	}
	echo $txt."<br>";

//example 3
$txt="replace [%main%] with \$main 
replace [%columnA%] with \$columnA 
";
$txt=preg_replace_callback("/\[%(.*)%\]/","makevar",$txt);
echo $txt."<br>";

function makevar($name){
global $main,$columnA;
return ${"$name[1]"};
} 

[sethadam1]

Thanks Sid.

Now, it is easier (can I avoid the callback function), if I put the vars into an array?

See, I want to stay away from str_replace, because it means I have to call it for each one or set them up individually.

I was thinking maybe:

$globals[main] = "main bit";
$globals[columnA] = "1";

then:

$txt=preg_replace("/[%(a-z+)%]/",$globals[$1],$tpl);

Would that work? To be fair - I tried it, it didn't. So the real question is, what's wrong with that?

[sidney]

i think it is only possible with the call back function

saying that i would use the str_replace as it is definatly faster
than using regexp

below using eample 1 and 3 looping 1000 times each

str_replace
replace main bit with $main replace 1 with $columnA - in 0.0129251480103

preg_replace_callback
replace main bit with $main replace 1 with $columnA - in 0.0346081256866

[sethadam1]

saying that i would use the str_replace as it is definatly faster
than using regexp

Yeah, str_replace is always going to be faster than a regex, but with a regex, I wouldn't have to specify what the input and output are, I'd just say "swap anything in the bracket percents with a variable by that name."

Oh well, I've got it working using str_replace. Thanks for your help.

[sidney]

you dont need to tell example one the match it gets it for the array index

[sethadam1]

I got it! I knew it could be done!

	
$tpl = preg_replace("/\[%([a-zA-Z0-9\[\]]+)%\]/e","\$\\1",$tpl);

[Weedpacket]

[man]str_replace[/man] can take arrays as well.....