<?php
 
$url = "animacao/!?page))/!@2?s*!=";
 
// pega tudo o que for um caractere de palavra de az, AZ, 0-9, incluindo o caractere _ (sublinhado).
// OU pega a parte que tem ( ?s )
preg_match_all('/(\w|\?s)+/', $url, $partes);
 
// nova url que será usada
$novaUrl = "";
 
foreach($partes[0] as $parte){
    if(strpos($parte, "?s")){
        // se a parte a ser analisada for ( ?s ) insira na $novaUrl com um ( = ) no final
        $novaUrl .= $parte."=";
        continue; // continue o loop
    }
    // qualquer outra parte insere com uma barra no final
    $novaUrl .= $parte."/";
}
 
// se o último caracter for uma barra ( / ) retire ela da string
if(substr($novaUrl,  -1) == "/")
$novaUrl = substr($novaUrl, 0, -1);
 
// mostra o resultado
echo $novaUrl;

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