Working on IBM i
IBM i users work on a 5250 green screen or its web and client tools. Commands follow a verb-plus-object pattern, such as WRKACTJOB (work with active jobs), and F4 prompts any command. Objects live in libraries, a library list decides where the system looks, and work runs as jobs in subsystems such as QBATCH and QINTER.
The screen
IBM i uses the 5250 terminal data stream, its equivalent of the mainframe's 3270. Most people use IBM i Access Client Solutions for 5250 emulation, and IBM Navigator for i in a browser. Like a 3270, a 5250 screen sends input when you press Enter or a function key: F3 exits, F12 cancels and F4 prompts the current command, showing every parameter.
CL commands
Commands are written in CL (Control Language) and named by joining short verbs and nouns, so you can often guess them:
| Command | Meaning | Nearest z/OS idea |
|---|---|---|
| WRKACTJOB | Work with active jobs | SDSF DA panel or D A,L |
| WRKSPLF | Work with spooled files (your output) | SDSF output queues |
| DSPJOBLOG | Display job log | The job's JESMSGLG and JESYSMSG |
| SBMJOB | Submit a job to a job queue | Submitting JCL |
| WRKOBJ / DSPLIB | Work with objects / display a library | ISPF data set list |
| DSPMSG QSYSOPR | Display messages in the system operator message queue | The operator console |
Libraries and the library list
Objects live in libraries. Libraries do not nest: every library is itself an object in the system library QSYS. A job's library list (*LIBL) is the ordered list of libraries searched when a program names an object without a library, much like a STEPLIB or a search path. Changing the library list, for example with ADDLIBLE or EDTLIBL, changes which version of a program or file is found.
Jobs, subsystems and queues
- Work runs as jobs inside subsystems: QINTER for interactive sessions, QBATCH for batch, QSPL for spooled output, and others defined by the site.
- Batch jobs wait on a job queue (*JOBQ) until their subsystem can run them; output goes to an output queue (*OUTQ).
- Messages needing an answer go to message queues; QSYSOPR is the system operator's queue.
Which function key prompts the current CL command, showing its parameters? (for example F1)
Show a hint
The same key prompts commands in many IBM i screens.
Show the solution
F4.
Common mistakes
Type the command name and press F4: IBM i shows every parameter with help.
The same program name can exist in several libraries. The library list decides which one runs.
Ending a job (option 4) is like cancelling one on z/OS: check what it is and agree it with the owner.
What you will see at work
- Operators on IBM i watch QSYSOPR and WRKACTJOB much as z/OS operators watch the console and SDSF.
- Developers often work in RPG, CL and SQL, using VS Code or IBM's Rational Developer for i as well as the green screen.
- Night batch on IBM i also uses schedulers, including the built-in job scheduler or products such as Robot Schedule.
Key terms
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