JelmerVernooij Samba Team

jelmer@samba.org

25 March 2003 Computers communicate in numbers. In texts, each number will be translated to a corresponding letter. The meaning that will be assigned to a certain number depends on the character set(charset) that is used. A charset can be seen as a table that is used to translate numbers to letters. Not all computers use the same charset (there are charsets with German umlauts, Japanese characters, etc). Usually a charset contains 256 characters, which means that storing a character with it takes exactly one byte. There are also charsets that support even more characters, but those need twice(or even more) as much storage space. These charsets can contain 256 * 256 = 65536 characters, which is more then all possible characters one could think of. They are called multibyte charsets (because they use more then one byte to store one character). A standardised multibyte charset is unicode, info available at www.unicode.org. Big advantage of using a multibyte charset is that you only need one; no need to make sure two computers use the same charset when they are communicating. Old windows clients used to use single-byte charsets, named 'codepages' by microsoft. However, there is no support for negotiating the charset to be used in the smb protocol. Thus, you have to make sure you are using the same charset when talking to an old client. Newer clients (Windows NT, 2K, XP) talk unicode over the wire. As of samba 3.0, samba can (and will) talk unicode over the wire. Internally, samba knows of three kinds of character sets: unix charset This is the charset used internally by your operating system. The default is ASCII, which is fine for most systems. display charset This is the charset samba will use to print messages on your screen. It should generally be the same as the unix charset. dos charset This is the charset samba uses when communicating with DOS and Windows 9x clients. It will talk unicode to all newer clients. The default depends on the charsets you have installed on your system. Run testparm -v | grep "dos charset" to see what the default is on your system.