PHP正则表达式替换站点关键字链接后空白的解决方法

function ReplaceKeyword($linkDefs,$content){
$linkMap = array();

/*foreach($linkDefs as $row) {
$linkMap[] = explode(',', $row);
}*/
$linkMap = $linkDefs;

//把原有的链接替换成文字
foreach($linkMap as $row) {
$content = preg_replace('/(<a.*"'.$row[1].'">'.$kwd.'</a>', $content, $th_num ,$count); // 所有的匹配项都会被替换
$k_count+=$count;
}

//把代替子关键字的字符串替换回来
foreach($tmpKwds as $tmp=>$kwd) {
$content = str_replace($tmp, $kwd, $content);
}
$result = array($content,$k_count);

return $result;
unset($result);
unset($tmp);
unset($tmpKwds);
unset($kwd);
unset($count);
unset($config);
unset($linkMap);
unset($linkDefs);
unset($tmpKwd);
unset($content);
unset($th_num);
unset($row);
unset($k_count);
}