Filenames

Different operating systems have different restrictions on file names:

• Mac filenames can be up to 31 characters long, and can have any character in them except ':'. They are case-sensitive.
• Unix filenames can be up to 255 characters long. They can contain any character, although space characters, '*', '?', '/' and others have special meanings and may cause problems. They are case-sensitive.
• Windows 95 and Windows NT filenames can be up to 255 characters long. They can contain almost any character but you can easily get into trouble by using spaces and other odd characters. They try to act as though they are case-sensitive but they're not. Older applications (16-bit) require the more restrictive DOS filenames even if they're being used under Windows 95 or NT.
• Filenames under Windows 3 and DOS may contain only letters and digits, the underscore (_) and hyphen (-) characters, and a single period (.) to indicate the file type. Filenames are not case sensitive. The file type cannot be more than 3 characters long, and the rest of the filename cannot be more than 8 characters long.
• VMS filenames may contain letters and digits; the underscore (_), hyphen (-) and dollar ($) characters; and a single period (.) to indicate the file type. Filenames are not case sensitive. The parts before and after the period may each be up to 39 characters long.

A conservative approach is to restrict yourself to filenames with

• moderate length
• lower-case letters
• digits
• the characters '_' and '-'
• a single '.'

If you stick with the DOS length restrictions (8.3) then your filenames will be acceptable just about anywhere.

Last modified: Tue, 2007 Mar 6 20:10:38