If you are used to the green screen world of 5250 sessions and CL commands but want to tap into open-source tools like MariaDB on your Power Systems box, understanding SSH and shells is a must. These let you run commands remotely or in a command-line interface right on IBM i, making installs and scripting smoother alongside your RPG, COBOL, or DB2 work. In this lesson, we will demystify the buzzwords like SSH, IFS, Bash, and more, with a focus on how they fit into your IBM i programming workflows.
We will use SSH in examples here, setting the stage for things like a MariaDB setup. Let's break it down step by step so you can get comfortable and productive.
What is SSH and Why Use It on IBM i?
SSH stands for Secure Shell, a protocol for securely connecting to a remote computer like your IBM i server. It encrypts your session, which is key for safe command execution over networks. On IBM i, SSH lets you log in from your PC to run PASE commands, access the Integrated File System (IFS), or manage open source packages without relying solely on 5250 emulators.
Confusingly, people often call any client program that uses this protocol "SSH" too. Once connected, you type commands on the host (your IBM i) and see results in your local terminal. For programmers, this means quick access to bash scripts, Yum installs, or debugging PHP apps integrated with your RPG code. IBM i supports SSH natively in PASE, so enable it with CFGTCPAPP *SSHD if it is not already running.
Understanding Shells: BSH and BASH
A shell is your command-line interface to the operating system, where you enter commands and get output. On IBM i, you have options like QShell (STRQSH) for a Unix-like experience, but for open source work, we often use Bourne Shell variants.
BSH, or Bourne Shell, is the classic shell program. It provides basic command interpretation and is also a language for writing shell scripts, those handy automation files ending in .sh. Think of it as a way to batch CL-like commands but in a Unix style, useful for looping through IFS files or calling RPG programs from scripts.
BASH, or Bourne Again Shell, is the enhanced version. It adds features like better history recall, tab completion, and programmable prompts. On IBM i, Bash comes with the open source environment via Yum, making it ideal for complex scripts that tie into your programming tasks, like deploying web apps or querying DB2 with SQL tools.
To start a shell on IBM i, use QP2TERM from a 5250 session for a PASE terminal, or SSH in for remote access. From there, type bash to switch to BASH if needed.
Tools for SSH Access: PuTTY, VS-Code, and IBM i Terminal
You need a client to connect via SSH. PuTTY is a popular free Windows tool that opens an SSH session to your IBM i. Just enter your host IP, port 22 (default), and credentials like QSECOFR or your user profile. It is simple for quick tasks, but lacks integration with code editors.
For a more programmer-friendly option, try VS-Code with its integrated QShell terminal. Install the IBM i extension pack, connect to your system, and run PASE commands, scripts, or tools right in the editor. This keeps your workflow tight: edit RPG source, then SSH to test a Bash script or install packages, all without switching windows.
In this lesson series, especially for MariaDB installs, we will stick with the built-in IBM i SSH terminal from the green screen (or your emulator's white screen). Start it with CALL QP2TERM, then use ssh localhost or ssh your-ibm-i-ip to connect. It is straightforward and keeps you in the IBM i ecosystem, perfect for learning without extra PC setup.
Tying It All Together for IBM i Programming
SSH and shells open doors for modernizing your IBM i apps. Use them to navigate the IFS (STRIFS or cd / in shell), install open source via Yum, or script deployments that call your CL or RPG programs. For example, in a MariaDB setup, SSH into PASE to run mysqld commands or edit configs in /QOpenSys.
Practice by SSHing in, starting Bash, and running simple commands like ls /QOpenSys/pkgs/bin to list open source tools. This blends seamlessly with your programming, letting you build hybrid apps with PHP frontends and DB2 backends.
There you have it, a solid intro to SSH and shells on IBM i. This sets you up for advanced tasks like database installs or API scripting.