<?php
    function curl($url, $post = false)
    {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_URL, $url);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        if($post) curl_setopt($curl, CURLOPT_POSTFIELDS, $post);
        $sonuc = curl_exec($curl);
        return $sonuc;
    }
    $url = curl('http://www.mevzuat.gov.tr/Kanunlar.aspx');
    preg_match('#id="__VIEWSTATE" value="(.*?)"#si', $url, $viewstate);
    preg_match('#id="__EVENTVALIDATION" value="(.*?)"#si', $url, $validation);
    $aranacak = 'a';
    echo curl('http://www.mevzuat.gov.tr/Kanunlar.aspx', '__EVENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE='.urlencode($viewstate[1]).'&__EVENTVALIDATION='.urlencode($validation[1]).'&ctl00%24ContentPlaceHolder1%24TBAranacakIfade='.$aranacak.'&ctl00%24ContentPlaceHolder1%24DDLAranacakYer=0&ctl00%24ContentPlaceHolder1%24TBKanunNumarasi=&ctl00%24ContentPlaceHolder1%24DDLNitelik=&ctl00%24ContentPlaceHolder1%24TBTarih1=&ctl00%24ContentPlaceHolder1%24TBTarih2=&ctl00%24ContentPlaceHolder1%24ButtonAra=Ara');