MPE/iX Shell and Utilities Reference Manual, Vol 2

Directories
This section provides an overview of implementation considerations you must understand when creat-
ing and managing MPE/iX directories through MPE/iX
Shell and Utilities.
You can find additional information about MPE/iX directories in New Features of MPE/iX: Using the
Hierarchical File System (32650-90351).
MPE/iX Directories
MPE/iX hierarchical directory services present an integrated view of the file system. You can create
files and hierarchical directories anywhere in the file system.
MPE/iX accounts and groups are special directories that serve as hierarchical directories while continu-
ing to serve as classic MPE accounts and groups.
MPE/iX Shell and Utilities can access any file in the file system hierarchy using hierarchical file name
syntax. This includes files in the classic MPE directory structure. For example, both of the following
fully qualified file name specifications refer to the same file.
/MYACCT/MYGROUP/MYFILE
MYFILE.MYGROUP.MYACCT
MPE/iX Directory Features
The following sections describe special features of the MPE/iX
root directory, MPE/iX account and group
directories, hierarchical directories, and the dot and dot-dot directories. You need to understand these
special features to create and manage directories through
MPE/iX Shell and Utilities.
Root Directory Features
• You cannot rename, copy, or remove the MPE/iX root directory (/).
• Only users with SM capability can create objects directly under the root directory.
• Access permissions for the root directory are read and execute access for all users and write
access for none. Attempts to use chmod to remove or change access permissions of the root direc-
tory result in a system error (see syserror(3)).
• Names of files and hierarchical directories created directly under the root directory cannot exceed
16 characters in length.
• The root directory, MPE/iX account directories, and hierarchical directories and files at all levels
under the root directory are restricted to the MPE/iX system volume set.
• The root directory does not contain explicit dot (.) and dot-dot (..) directories; however, dot and
dot-dot directory behavior is supported. You can open the dot and dot-dot directories just like any
A-10 MPE/iX Implementation Considerations