DIR - Directory
In the z/OS environment, a directory primarily refers to a special type of file within the z/OS UNIX System Services (USS) hierarchical file system that contains entries for other files and subdirectories. It serves to organize and provide a logical structure for storing data and programs, similar to directories in other UNIX-like operating systems. Additionally, the term can refer to the internal directory structure of a Partitioned Data Set (PDS) or Partitioned Data Set Extended (PDSE), which manages its members. In the context of z/OS, a "directory" primarily refers to the internal index structure of a Partitioned Data Set (PDS) or Partitioned Data Set Extended (PDSE) that lists its individual members. More broadly, it can also refer to a directory within the UNIX System Services (USS) Hierarchical File System (HFS) or zFS, which organizes files and subdirectories in a hierarchical structure.
Key Characteristics
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- Hierarchical Structure (USS): USS directories form a tree-like structure, starting from the root (
/), allowing for nested organization of files and other directories, enabling complex application architectures. - Entry Management (USS): A directory entry contains the name of a file or subdirectory and a pointer to its
inode, which holds metadata like permissions, ownership, and physical location on the underlyingzFSorHFSfile system. - Permissions and Ownership (USS): Like other USS files, directories have associated permissions (read, write, execute) for the owner, group, and others, controlling who can list, create, or delete entries within them.
- Mount Points (USS): z
- Hierarchical Structure (USS): USS directories form a tree-like structure, starting from the root (