| 扩展名 | 前几字节 | | --- | --- | | .rmvb | .RMF | | .zip | PK | | .rar | Rar! | | .exe | MZ | | .pdf | %PDF-1.X | | .chm | ITSF | | .bmp | BM | | .png | 塒NG | | .gif | GIF89a | | .wmv | 0&瞮巉 | | .flv | FLV | | .mp3 | FF FB 30(HEX值) | |.swf | FWS或CWS |
看文件的扩展名是不可靠的。必须得看二进制。