File naming

Strings of 1 or more characters may be used to name a regular file, directory file or special file. The characters may be any from the set of all character values excluding ``null'' and ``slash'', ``/''. The following are examples of legal directory or file names:

   	memo	MEMO	section2	ref:list
   	file.d	chap3+4	item1-10	outline

A regular file, special file or directory may have any name that conforms to the following rules:

• All characters other than / are legal.

• Non-printing characters including space, tab and backspace, are best avoided. If you use a space or tab in a directory or filename, you must enclose the name in quotation-marks on the command-line.

• Note that it is generally unwise to use ``*'', ``?'', ``!'', ``['' or ``]'' as part of filenames because of the special meaning given these characters for filename expansion by the command interpreter (see system(3S)). Other characters to avoid are the hyphen, ``<'', ``>'', backslash, single and double quotes, accent grave, vertical bar, caret, curly braces and parentheses.

• Avoid using a ``+'', ``-'' or ``.'' as the first character in a filename.

• Upper case and lower case characters are distinct to the UNIX system. For example, the system considers a directory (or file) named draft to be different from one named DRAFT.