Shift_JIS series means a locale that is equivalent to Shift_JIS, used as a standard on Japanese Windows. In the case of Shift_JIS, for example, if a Japanese filename consists of 0x8ba4 and 0x974c (a 4-bytes Japanese character string meaning “share”) and “.txt” is written from Windows on Samba, the filename on UNIX becomes 0x8ba4, 0x974c, “.txt” (an 8-byte BINARY string), same as Windows.

Since Shift_JIS series is usually used on some commercial-based UNIXes; hp-ux and AIX as the Japanese locale (however, it is also possible to use the EUC-JP locale series). To use Shift_JIS series on these platforms, Japanese filenames created from Windows can be referred to also on UNIX.

If your UNIX is already working with Shift_JIS and there is a user who needs to use Japanese filenames written from Windows, the Shift_JIS series is the best choice. However, broken filenames may be displayed, and some commands that cannot handle non-ASCII filenames may be aborted during parsing filenames. Especially, there may be “\ (0x5c)” in filenames, which need to be handled carefully. It is best to not touch filenames written from Windows on UNIX.

Note that most Japanized free software actually works with EUC-JP only. It is good practice to verify that the Japanized free software can work with Shift_JIS.

EUC-JP series means a locale that is equivalent to the industry standard called EUC-JP, widely used in Japanese UNIX (although EUC contains specifications for languages other than Japanese, such as EUC-KR). In the case of EUC-JP series, for example, if a Japanese filename consists of 0x8ba4 and 0x974c and “.txt” is written from Windows on Samba, the filename on UNIX becomes 0xb6a6, 0xcdad, “.txt” (an 8-byte BINARY string).

Since EUC-JP is usually used on open source UNIX, Linux, and FreeBSD, and on commercial-based UNIX, Solaris, IRIX, and Tru64 UNIX as Japanese locale (however, it is also possible on Solaris to use Shift_JIS and UTF-8, and on Tru64 UNIX it is possible to use Shift_JIS). To use EUC-JP series, most Japanese filenames created from Windows can be referred to also on UNIX. Also, most Japanized free software works mainly with EUC-JP only.

It is recommended to choose EUC-JP series when using Japanese filenames on UNIX.

Although there is no character that needs to be carefully treated like “\ (0x5c)”, broken filenames may be displayed and some commands that cannot handle non-ASCII filenames may be aborted during parsing filenames.

Moreover, if you built Samba using differently installed libiconv, the eucJP-ms locale included in libiconv and EUC-JP series locale included in the operating system may not be compatible. In this case, you may need to avoid using incompatible characters for filenames.

UTF-8 means a locale equivalent to UTF-8, the international standard defined by the Unicode consortium. In UTF-8, a character is expressed using 1 to 3 bytes. In case of the Japanese language, most characters are expressed using 3 bytes. Since on Windows Shift_JIS, where a character is expressed with 1 or 2 bytes is used to express Japanese, basically a byte length of a UTF-8 string the length of the UTF-8 string is 1.5 times that of the original Shift_JIS string. In the case of UTF-8, for example, if a Japanese filename consists of 0x8ba4 and 0x974c, and “.txt” is written from Windows on Samba, the filename on UNIX becomes 0xe585, 0xb1e6, 0x9c89, “.txt” (a 10-byte BINARY string).

For systems where iconv() is not available or where iconv()'s locales are not compatible with Windows, UTF-8 is the only locale available.

There are no systems that use UTF-8 as the default locale for Japanese.

Some broken filenames may be displayed, and some commands that cannot handle non-ASCII filenames may be aborted during parsing filenames. Especially, there may be “\ (0x5c)” in filenames, which must be handled carefully, so you had better not touch filenames written from Windows on UNIX.

In addition, although it is not directly concerned with Samba, since there is a delicate difference between the iconv() function, which is generally used on UNIX, and the functions used on other platforms, such as Windows and Java, so far is concerens the conversion between Shift_JIS and Unicode UTF-8 must be done with care and recognition of the limitations involved in the process.

Although Mac OS X uses UTF-8 as its encoding method for filenames, it uses an extended UTF-8 specification that Samba cannot handle, so UTF-8 locale is not available for Mac OS X.

CAP encoding means a specification used in CAP and NetAtalk, file server software for Macintosh. In the case of CAP encoding, for example, if a Japanese filename consists of 0x8ba4 and 0x974c, and “.txt” is written from Windows on Samba, the filename on UNIX becomes “:8b:a4:97L.txt” (a 14 bytes ASCII string).

For CAP encoding, a byte that cannot be expressed as an ASCII character (0x80 or above) is encoded in an “:xx” form. You need to take care of containing a “\(0x5c)” in a filename, but filenames are not broken in a system that cannot handle non-ASCII filenames.

The greatest merit of CAP encoding is the compatibility of encoding filenames with CAP or NetAtalk. These are respectively the Columbia Appletalk Protocol, and the NetAtalk Open Source software project. Since these software applications write a file name on UNIX with CAP encoding, if a directory is shared with both Samba and NetAtalk, you need to use CAP encoding to avoid non-ASCII filenames from being broken.

However, recently, NetAtalk has been patched on some systems to write filenames with EUC-JP (e.g., Japanese original Vine Linux). In this case, you need to choose EUC-JP series instead of CAP encoding.

vfs_cap itself is available for non-Shift_JIS series locales for systems that cannot handle non-ASCII characters or systems that share files with NetAtalk.

To use CAP encoding on Samba-3, you should use the unix charset parameter and VFS as in the VFS CAP smb.conf file.

You should set CP932 if using GNU libiconv for unix charset. With this setting, filenames in the “cap-share” share are written with CAP encoding.