How to use php functions in smarty

/**
* Use php functions in smarty template engine
* by bbs.it-home.org
*/
require 'libs/Smarty.class.php';
 $smarty=new Smarty;
 $smarty->compile_check=true;
 $smarty ->debugging=true;
 $str1='testtesttesttest';
 $str2='this is a';
 $str3='Script Academy bbs.it-home.org';
 $str4='this is four' ;
 $smarty->assign('str1',$str1);
 $smarty->assign('str2',$str2);
 $smarty->assign('str3',$str3);
 $smarty->assign('str4',$str4);
 $smarty->display('testtest.tpl');
?>




{$str1|strlen}
{$str2|strpos:'is'}
{'utf- 8'|iconv:'gb2312':$str3}
{$str4|str_pad:20:"-=":STR_PAD_LEFT}

< ;/html>

Output results: 16 2

Test: -=-=-=-=this is four

Instructions: Use four variables to handle 1, 2, 3, and 4 unavailable parameters respectively. Here is a record. When calling variables in the template, when there is only one parameter, just {$str1|function name}. When there are two functions When there are three parameters, {first parameter | function name: second parameter}, when there are three parameters, {first parameter | function name: second parameter: third parameter}, when there are 4, 5,,,parameters, and so on,,,,,,,,,,,,

When programming, I used this:

{$name|str_ireplace:"$name":$arr

I would like to share it by the way, friends who are interested can think about it.