Introduction › SCL Statement Syntax Conventions › Rules for Coding Syntax › Long File and Path Name Syntax › HFSFile Syntax Rules

HFSFile Syntax Rules

A filename can be up to 255 characters long. To be portable, the filename should use only the characters in the POSIX portable filename character set:

• Uppercase or lowercase letters A through Z
• Numbers 0 through 9
• Period (.)
• Underscore (_)
• Hyphen (-)

Note: Do not include any nulls or slash characters in a filename.

Doublebyte characters are not supported in a filename and are treated as singlebyte data. Using doublebyte characters in a filename may cause problems. For instance, if you use a doublebyte character in which one of the bytes is a . (dot) or / (slash), the file system treats this as a special delimiter in the pathname.

The shells are case-sensitive, and distinguish characters as either uppercase or lowercase. Therefore, FILE1 is not the same as file1.

A filename can include a suffix, or extension, that indicates its file type. An extension consists of a period (.) and several characters. For example, files that are C code could have the extension .c, as in the filename dbmod3.c. Having groups of files with identical suffixes makes it easier to run commands against many files at once.