问PHP删除特定字符串之前的所有字符

EN

echo strstr($str, 'www/audio');

$string="We have www/audio path where the audio files are stored";  //Considering the string like this

strstr($string, 'www/audio');

$expStr=explode("www/audio",$string);
$resultString="www/audio".$expStr[1];

function strright($str, $separator) {
    if (intval($separator)) {
        return substr($str, -$separator);
    } elseif ($separator === 0) {
        return $str;
    } else {
        $strpos = strpos($str, $separator);

        if ($strpos === false) {
            return $str;
        } else {
            return substr($str, -$strpos + 1);
        }
    }
}

function strleft($str, $separator) {
    if (intval($separator)) {
        return substr($str, 0, $separator);
    } elseif ($separator === 0) {
        return $str;
    } else {
        $strpos = strpos($str, $separator);

        if ($strpos === false) {
            return $str;
        } else {
            return substr($str, 0, $strpos);
        }
    }
}