某些網站通過http header信息限制下載文件，在linux下面可以使用wget來模擬realplay等的，http header信息。
wget --head "ClientID: WinNT_5.0_6.0.12.1056_play32_R30CND_zh-CN_686_axembed" --head "User-Agent: RMA/1.0 (compatible; RealMedia)"
http://localhost/head.php 說明：每一個header信息項用一個 --head參數來指定，可以多次使用 --head參數。
下面是我的
http://localhost/head.php獲得的header的信息：
Array
(
[User-Agent] => RMA/1.0 (compatible; RealMedia)
[Accept] => */*
[Host] => localhost
[Connection] => Keep-Alive
[ClientID] => WinNT_5.0_6.0.12.1056_play32_R30CND_zh-CN_686_axembed
)
以下是下載成功和不成功的http鏈接信息記錄：
> >從IE點播的http請求，播放成功。(VOD1.cap)
> >
> >GET /vod2/%5bTV%5dFZXF/01.rmvb HTTP/1.1
> >
> >Accept: */*
> >
> >User-Agent: RMA/1.0 (compatible; RealMedia)
> >
> >Icy-MetaData: 1
> >
> >Bandwidth: 10485800
> >
> >ClientID: WinNT_5.0_6.0.12.1056_play32_R30CND_zh-CN_686_axembed
> >
> >GUID: 00000000-0000-0000-0000-000000000000
> >
> >Language: zh-CN, zh, *
> >
> >RegionData: 0
> >
> >SupportsMaximumASMBandwidth: 1
> >
> >Connection: Keep-Alive
> >
> >Host: 10.146.189.104
> >
> >Accept-Language: zh-CN, zh, *
> >
> >Accept-Encoding: gzip
> >
> >===================================================================
> >從realplayer直接打開對應文件播放成功。(vod2.cap)
> >
> >GET /vod2/%5bTV%5dFZXF/01.rmvb HTTP/1.1
> >
> >Accept: */*
> >
> >User-Agent: RMA/1.0 (compatible; RealMedia)
> >
> >Icy-MetaData: 1
> >
> >Bandwidth: 10485800
> >
> >ClientID: WinNT_5.0_6.0.12.1056_RealPlayer_R30CND_zh-CN_686
> >
> >GUID: 00000000-0000-0000-0000-000000000000
> >
> >Language: zh-CN, zh, *
> >
> >RegionData: 0
> >
> >SupportsMaximumASMBandwidth: 1
> >
> >Connection: Keep-Alive
> >
> >Host: 10.146.189.104
> >
> >Accept-Language: zh-CN, zh, *
> >
> >Accept-Encoding: gzip
> >
> >
> >===================================================================
