Using UNIX™ System Services and the Hierarchical File System
z/OS® UNIX™ System Services (USS) gives the z/OS® operating system an open standards interface. It contains a UNIX™ shell and utilities, which you can use to enter shell commands, write shell scripts, and work with the file system.
z/OS® UNIX™ provides a Hierarchical File System (HFS) for z/OS®. A file within z/OS® UNIX™ is called an HFS file. HFS files are organized in a hierarchy of files and directories in a tree much like UNIX™. A directory can contain files or other subdirectories.
To access the Hierarchical File System:
- Select option 8 (HFS) from the Primary Option Menu.
Z Data Tools displays the Access Hierarchical File System panel.
- On the Access Hierarchical File System panel, select the required option so that Z Data Tools invokes standard ISPF services to enable access to USS and HFS utilities.
If you are familiar with Z Data Tools functions, there is a convenient way to access HFS files. For basic functions, you can specify an HFS file in the same panels and batch commands as an z/OS® data set.
Z Data Tools can access an HFS file as a simulated QSAM/BSAM file. This means that at the I/O level, the file is seen as a single-volume, physical, sequential data set that resides on DASD. It is allocated dynamically or referred using a DD statement (PATH parameter).
The following sections summarize the main features and differences.