关于.DBF文件的第一个字节以及如何检测所使用的xbase版本（即文件其余部分的格式），我可以编译的最全面的列表是：
Byte 0
-----------
x xxx x 001 = 0x?1 not used
0 000 0 010 = 0x02 FoxBASE
0 000 0 011 = 0x03 FoxBASE+/dBASE III PLUS, no memo
x xxx x 100 = 0x?4 dBASE 7
0 000 0 101 = 0x05 dBASE 5, no memo
0 011 0 000 = 0x30 Visual FoxPro
0 011 0 001 = 0x31 Visual FoxPro, autoincrement enabled
0 011 0 010 = 0x32 Visual FoxPro, Varchar, Varbinary, or Blob-enabled
0 100 0 011 = 0x43 dBASE IV SQL table files, no memo
0 110 0 011 = 0x63 dBASE IV SQL system files, no memo
0 111 1 011 = 0x7B dBASE IV, with memo
1 000 0 011 = 0x83 FoxBASE+/dBASE III PLUS, with memo
1 000 1 011 = 0x8B dBASE IV, with memo
1 000 1 110 = 0x8E dBASE IV with SQL table
1 100 1 011 = 0xCB dBASE IV SQL table files, with memo
1 110 0 101 = 0xE5 Clipper SIX driver, with SMT memo
1 111 0 101 = 0xF5 FoxPro 2.x (or earlier) with memo
1 111 1 011 = 0xFB FoxBASE (with memo?)
| ||| | |||
| ||| | ||| Bit flags (not used in all formats)
| ||| | ||| -----------------------------------
| ||| | +++-- bits 2, 1, 0, version (x03 = level 5, x04 = level 7)
| ||| +------ bit 3, presence of memo file
| +++-------- bits 6, 5, 4, presence of dBASE IV SQL table
+------------ bit 7, presence of .DBT file
通过读取初始 .DBF 字节可以采用哪种标头格式？ （即，该文件是否使用版本 2 标头、版本 3 到 5 标头或版本 7 标头？）根本不清楚最佳逻辑是什么......
