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z/OS UNIX Shells and now SSH Terminals

By Claire Nelson posted Fri March 13, 2020 12:00 AM

IBM Explorer for z/OS lets you use z/OS UNIX shells to remotely execute UNIX programs and commands. If you need to run some basic commands, scripts or programs, or if you want to manage files, examine environment variables or do a grep search, this feature can come in handy. These shells interpret command output, allowing for seamless integration with z/OS UNIX files. Because resources are identified in the shell, you can do things like open files in editors and use content assist to navigate the file system.

As nice as some of z/OS UNIX shell features are, there are some limitations. Because this shell is not a TTY, you can't use it to run commands or programs that prompt for input. Tools requiring terminal emulation, like vi, won't work at all!

Enter SSH

SSH (Secure Shell) is one of the most ubiquitous protocols for accessing remote systems in the computing world. A secure replacement for telnet, rlogin, rexec and other protocols, SSH is an industry standard. Tools like Ansible and Git make use of SSH for remote access. In the UNIX world, pretty much everyone uses it.

And now, as of IBM Developer for z/OS 14.2.2, along with other products on the Aqua stack, you'll have the option to use SSH Terminals with your z/OS connections. The latest z/OS Explorer server has a host option that lets you use z/OS SSH Terminals with your Remote Systems Explorer connections. To enable it, your sysprog will need to uncomment the following in the rse.env host configuration file.


Initially, you won't see the new subsystem in the Remote Systems view, but the first time you connect to a server with the option enabled, z/OS SSH Terminals will show up alongside the other subsystems under your connection. As with z/OS UNIX Shells, you can start terminals from the subsystem or from a folder under z/OS UNIX Files.

z/OS SSH Terminals

Shells or Terminals?

So, which should you use? Each has advantages and disadvantages. Remote Shells give you integration with z/OS UNIX files. SSH terminals are fast and support TTY emulation. If you're already savvy with SSH clients, you'll most likely prefer z/OS SSH Terminals. Like many things in life, the answer depends on your preferences and the task at hand.


As the mainframe evolves, the influence of UNIX expands throughout the ecosystem. More than ever before, developers are taking advantage of UNIX tools and services on the mainframe. With z/OS UNIX Shells and now z/OS SSH Terminals, provided in IBM Explorer for z/OS Aqua, you're well equipped to exploit these tools and services.