30 Input/output library [input.output]

The name of a file.

Filenames dot and dot-dot, consisting solely of one and two period characters respectively, have special meaning.

The following characteristics of filenames are operating system dependent:

• The permitted characters.
  [ Example

  :

  Some operating systems prohibit the ASCII control characters (0x00 – 0x1F) in filenames.

  — end example

   ]
• The maximum permitted length.
• Filenames that are not permitted.
• Filenames that have special meaning.
• Case awareness and sensitivity during path resolution.
• Special rules that may apply to file types other than regular files, such as directories.