Macintosh File Name Translation

Services for Macintosh allows a Windows 2000 and a Macintosh computer to share files; however, conflicts can arise because of the different file naming conventions that are supported by each system.

As shown in Table 13.5, Windows 2000, Macintosh, and MS-DOS systems each follow different file-naming conventions.

Table   13.5 File-Naming Conventions

When a file with a long name (any name over 8.3 MS-DOS standard) is saved on an NTFS partition, the long name is maintained and a short name is created so that MS-DOS users can gain access to the file if they have permission to do so. For example, Macintosh users who create folders or files on an Services for Macintosh volume and use the 31-character limit see the original long names. MS-DOS users, however, see a shortened version of the file name. Furthermore, Windows 2000 system users see the longer Macintosh file names because NTFS has a 256-character file name limit.

Even though NTFS translates long names to short names, it is a good idea for users of systems that do not recognize large file names to name shared files following the 8.3 convention that is used by the FAT file system in MS-DOS. This simplifies file identification for users working on different platforms. This section explains how file translations work on Windows 2000–based servers that are running Services for Macintosh. For more information about file name translation, see Windows 2000 Server Help.

Naming Differences

In general, the FAT file naming system, which is used on MS-DOS systems, is more restrictive than the Macintosh system. The two systems differ in the following ways:

• Macintosh file names and folder names can have as many as 31 characters and can include blank spaces. FAT file names and directory names can have as many as eight characters, followed by an optional extension (signaled by a period and up to three additional characters), and they cannot include blank spaces.

• Macintosh file names and folder names can include any Macintosh character except a colon. MS-DOS file names and directory names have more exceptions, such as the following:
  / [ ] ; = " \ : | , * .

• Both Macintosh and MS-DOS file names and folder names (or directory names) can include extended characters; however, the Macintosh and MS-DOS extended character sets are different.

FAT file names and directory names are acceptable as Macintosh file names and folder names unless they contain extended characters not found in the Macintosh character set. In such cases, Macintosh users see valid characters substituted for the invalid ones.

Overview of Macintosh-to-8.3 Translation

When a file is created on a Macintosh and saved on a computer that is running Windows 2000 Server, the File Server for Macintosh first checks it for illegal NTFS characters. Then NTFS takes over the file translation process.

Services for Macintosh Functionality

When a Macintosh file name is saved on a computer that is running Windows 2000 Server, File Server for Macintosh component of Services for Macintosh does the following:

• If required, File Server for Macintosh changes illegal NTFS characters to the available range of Unicode characters, which are then mapped to the ANSI default character, a question mark (?). The result is that the file can be seen, but a use or client does not have access to it.

  • The following are the illegal NTFS characters:

  " / \ * ? < > | :

NTFS Functionality

When NTFS receives a legal NTFS name from File Server for Macintosh, it translates the name as follows:

• Macintosh names that are valid MS-DOS names do not change: The long name and short name are the same. For example, "Sample.art" remains "Sample.art."

• Long names are truncated to six characters, followed by a tilde and a unique number, for a total of eight characters (not including any extension).

• The last period (if any) in a long name signals the extension, which is retained.

• If the short name is a duplicate of another name (long or short), NTFS automatically modifies the short name of the new file or folder by truncating the name to six characters and adding a tilde an a number until it creates a unique name.

Note

If a Macintosh user gives a file or a folder a valid MS-DOS name, which makes translation to a short name unnecessary, the user might see a message that states that the name already exists and that the user must choose a new name. For example, this message appears if the user creates a file named Sales.dat when another file in the folder already has that name.

Mapping of Extended Characters

If Macintosh extended characters are used in file names or folder names that are saved to the computer that is running Windows 2000 Server by Macintosh users, the File Server for Macintosh translates these extended characters to the equivalent Unicode characters so that Windows 2000 users can see them.

If MS-DOS extended characters are used in file names or directory names that are saved to the computer that is running Windows 2000 Server by Windows 2000 users, the File Server for Macintosh also translates these extended characters to the equivalent Macintosh ANSI characters so that Macintosh users can see them.