如何使用正则表达式去掉被双引号包裹的数字两边的双引号

从某云导出数据库表为CSV格式，发现bigint字段两边也被加上了双引号，不应该啊不应该，如何去掉呢？

示例记录：

"31189","aaaa","$P$BFMnptFob/7bmU2o***PNqorSMKzLs0","aaaa","aaa@qq.com","","2015-02-27 02:18:54","","0","oo","0000-00-00"

"31191","bbbb","$P$BeRmQEYPfnOfKrKpF***9osOe3v0aq/","bbb","bbb@qq.com","","2015-02-27 04:23:52","","0","bbb","0000-00-00"

回复内容：

从某云导出数据库表为CSV格式，发现bigint字段两边也被加上了双引号，不应该啊不应该，如何去掉呢？

示例记录：

"31189","aaaa","$P$BFMnptFob/7bmU2o***PNqorSMKzLs0","aaaa","aaa@qq.com","","2015-02-27 02:18:54","","0","oo","0000-00-00"

"31191","bbbb","$P$BeRmQEYPfnOfKrKpF***9osOe3v0aq/","bbb","bbb@qq.com","","2015-02-27 04:23:52","","0","bbb","0000-00-00"

为啥要去掉php 有对应函数
http://php.net/str_getcsv

昂，已经弄了个php版本的处理了

function fucking_aliyun_rds($line){

    if(!$line) return;
    $line=(string)$line;

    $pattern='/^\"\d{1,5}\"/';
    $int=$replacement=false;
    if(preg_match($pattern, $line, $matches)){

        $int=(int)str_replace('"', '', $matches[0]);
    }else{
        return $line;
    }

    if($int){
        $replacement = $int;
        $line=preg_replace('""', '',$line);
        $b=preg_replace($pattern, $replacement, $line);

    }
    $b.="\t";
    return $b;

}

$f = fopen ("wp_users.txt", "r");
$ln= 0;
while (! feof ($f)) {
$line= fgets ($f);
/* ++$ln;/
/printf ( $ln);*/
if ($line===FALSE) {
}
else{

    $a=fucking_aliyun_rds($line);
    echo $a;


}

}
fclose ($f);