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) {
$content = preg_replace('/(<a.*?>s*)('.$row[0].')(s*</a>)/sui',$row[0],$content);
}
//关键字从长至短排序
usort($linkMap,'_sortDesc');
//var_dump($linkMap);
$tmpKwds = array(); //存放暂时被替换的子关键字
$k_count=0;
foreach($linkMap as $i=>$row) {
list($kwd,$url) = $row;
for($j=$i+1; $j<count($linkMap); $j++) {
$subKwd = $linkMap[$j][0];
//如果包括其他关键字,暂时替换成其他字符串,如 茶叶 变成 
if(strpos($kwd,$subKwd) !== false) {
$tmpKwd = '';
$kwd = str_replace($subKwd,$tmpKwd,$kwd);
$tmpKwds[$tmpKwd] = $subKwd;
}
}
//把文字替换成链接
require(MLEINC.'/config/globals.config.php');
$th_num = $config['keyword_num']; //关键字替换次数
$content = preg_replace('/('.$row[0].')/sui','<a href="'.$row[1].'">'.$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);
}