用curl请求一个页面。HTTP协议有时候不返回Content-Length 该怎么办

[lovewangya]

用curl请求一个页面。HTTP协议有时候不返回Content-Length 该怎么办

例如这个页面:http://bbs.admin5.com/forum-404-1.html
不返回：Content-Length
HTTP/1.1 200 OK Date: Sat, 21 Nov 2009 07:17:55 GMT Server: Apache/2 X-Powered-By: PHP/5.2.9 Set-Cookie: cdb_sid=XXFvKx; expires=Sat, 28-Nov-2009 07:17:55 GMT; path=/; httponly Vary: Accept-Encoding,User-Agent Content-Type: text/html

但用ie访问则返回这个字段如下：
HTTP/1.1 200 OK
Vary:Accept-Encoding,User-Agent
Connection:close
Transfer-Encoding:chunked
Content-Type:text/html
Date:Sat, 21 Nov 2009 07:21:35 GMT
Set-Cookie:cdb_sid=OYY043; expires=Sat, 28-Nov-2009 07:21:35 GMT; path=/; httponly
Server:Apache/2
X-Powered-By:PHP/5.2.9
[color=#FF00FF]Content-Length:57675[/color]