Path names requirements

The term path name refers to a file-system name, volume name, directory name, and file name.

Path names for volumes in directly attached devices

In the path name for volumes in directly attached devices, the forward slash (/) is used as a separator character. The path name must begin with a forward slash and contain no more than 294 characters. See the following example for the format of a path name on a directly attached device:
/QOPT/VOL_NAME/DIRECTORY_NAME/SUB_DIR1/.../SUB_DIRn/FILE_NAME
QOPT refers to the optical file system. You must use it to qualify the optical file system when issuing calls to optical support through the HFS API or the Unix-type APIs. The portion of the path following the file system name cannot contain more than 289 characters. For the rules for using path names, see the following items:
  • A path name can consist of any EBCDIC characters, except the characters that are listed below:
    • X'00' through X'3F'
    • X'FF'
    • The quotation mark (")
    • The asterisk (*)
    • The less than (<) and greater than (>) signs
    • The question mark (?)
    • The hyphen (-)
    • The back slash (\)

    When accessing UDF formatted volumes through the integrated file system APIs, the only characters not valid are X’00’ through X’3F’, X’FF’, and back slash.

  • The volume identifier can be a maximum of 32 characters for HPOFS media format, and a maximum of 30 characters for UDF media format. The identifier must contain only alphabetic characters (A through Z), numeric characters (0 through 9), a hyphen (-), an underscore(_), or a period (.). The first character must be alphabetic or numeric, and the identifier cannot contain blanks.
  • You can include one or more directories in the path name, but it is not required. The total number of characters in all of the subdirectories together cannot exceed 256 characters.
  • The file name is the last element in the path. The directory length in the path limits the file name length. The directory name and file name combined cannot exceed 256 characters. The preceding forward slash of the directory name is considered part of this 256 characters.

Path names for volumes in LAN-attached devices

For a path name on an optical volume in a LAN-attached optical device, the forward slash (/) is used as a separator character. The path name must begin with a forward slash and contain no more than 261 characters. See the following example for the format of a path name on an optical volume in a LAN-attached optical device:
/QOPT/VOL_NAME/DIRECTORY_NAME/SUB_DIR1/.../SUB_DIRn/FILE_NAME
QOPT refers to the optical file system, and must be used to qualify the optical file system when issuing calls to optical support through the HFS or integrated file system APIs. The portion of the path following the file system name cannot contain more than 256 characters. For the rules for using path names on LAN-attached devices, see the following items:
  • For the characters that are allowed in path names, see IBM 3995 Optical Library Dataserver Operator Guide for C-Series Models, GA32-0352. To find this publication, go to IBM® Publications Center (http://www.ibm.com/e-business/linkweb/publications/servlet/pbi.wss) and search for the publication number.
  • The volume name is required and can contain a maximum of 32 characters.
  • One or more directories can be included in the path name, but it is not required. The total number of characters in all of the subdirectories together cannot exceed 254 characters.
  • The file name is the last element in the path. The file name length is limited by the volume and directory length in the path. The volume name, directory name, and file name combined cannot exceed 256 characters. The preceding forward slashes of the volume and directory name are considered part of the 256 characters.