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Capturing Operator Command Output with CMDLIST

OpCon Command-type events issue a z/OS operator command via the LSAM's internal MGCRE interface but do not capture the response — the only feedback the user sees is "Command Issued" or "Command Failed" on the event. When you need to see what the command actually produced (for example, the output of D T, D A,L, or $D Q), schedule the command as a REXX-type event that runs the CMDLIST sample exec instead. CMDLIST activates an Extended MCS console, issues the command, harvests the responses, and writes them to SYSTSPRT — which is retrievable through the standard JORS interface alongside the event.

Where to Get It​

CMDLIST ships as a sample, not as an installed module. Copy samples/cmdlist.rexx from the LSAM source distribution into a library that is concatenated to the LSAM's SYSEXEC DD (the same library used for any other dynamic REXX event — typically OPCON.ver.INSTLIB or a customer-owned exec library).

note

The exec must be named CMDLIST (or whatever name you choose to invoke from OpCon). REXX names are case-insensitive on z/OS.

note

If your LSAM release package does not include a samples directory, contact Continuous support to obtain cmdlist.rexx.

How It Works​

CMDLIST is 51 lines of REXX:

  1. Activates an Extended MCS console for the REXX session via console activate.
  2. Sets a console profile that suppresses solicited/unsolicited display routing (consprof soldisplay(no) unsoldisplay(no)) so responses come back through the message queue, not the operator console.
  3. Issues each command via address console <cmd>.
  4. Drains the response queue with the REXX built-in getmsg("resp.",,,,1) (1-second poll, looped until idle).
  5. says each captured line — which lands in SYSTSPRT.
  6. Deactivates the console.

Because each REXX event runs in its own XPSEVENT address space, its console is private to that run.

Invocation Modes​

Mode 1 — Inline Command​

Use this for ad-hoc commands defined entirely within the OpCon event.

Form:

CMDLIST % <z/OS command>

The % argument tells CMDLIST to skip the command dataset and use the rest of the parm as a single command.

OpCon event definition:

FieldValue
Job TypeREXX (R)
ProcedureCMDLIST
Parameters% D T

Resulting SYSTSPRT:

D T
 IEE136I LOCAL: TIME=14.23.07 DATE=2026.134  UTC: TIME=18.23.07 DATE=2026.134

The first line is echoed from the exec's say cmdstring; the second line is the captured response.

Mode 2 — Command List in a Dataset​

Use this when you want a single event to issue several commands, or when the command text is too long or sensitive to keep in the event definition.

Form:

CMDLIST <member>

CMDLIST reads opcon.commands(<member>) and issues each line whose first word is MVSCMD. Lines without that prefix are ignored, so you can mix comments in.

Default command dataset:

The exec hardcodes the command dataset name as:

cmddsn = 'opcon.commands'

The TSO ALLOC command wraps the value in single quotes, so it is treated as fully qualified — TSO does not prepend the running userid. By default the exec opens OPCON.COMMANDS(<member>) literally. To use a different name, edit the exec — there is no parameter for it.

Example member contents (opcon.commands(DAILYCHK)):

* Daily system check
MVSCMD D T
MVSCMD D A,L
MVSCMD D ASM
MVSCMD $D Q

OpCon event definition:

FieldValue
Job TypeREXX (R)
ProcedureCMDLIST
ParametersDAILYCHK

Retrieving the Captured Output​

Output goes to the REXX event's SYSTSPRT, which is allocated as a SYSOUT dataset under the class set by the MSGCLASS parameter in XPSPRMxx (default A). The event's spool output is retrievable through the standard JORS interface — OpCon users see the captured response lines next to the event in the job-output viewer with no extra configuration.

Authorization​

Commands routed through address console are subject to standard z/OS SAF checks. Two classes typically apply:

ClassResourceRequired Access
OPERCMDSThe specific MVS or JES command being issued (e.g., MVS.DISPLAY.TIME)READ (or higher for action commands)
OPERCMDSMVS.MCSOPER.consnameREAD (granted automatically for dynamically-named consoles in most shops)

Which USERID Runs CMDLIST​

CMDLIST runs in a dynamic address space whose USERID is assigned by SAF from the STARTED class. With XPSDYNAM=IEESYSAS (default), the matched key is CMDLIST.CMDLIST; if XPSDYNAM names a customer proc, the key is procname.CMDLIST.

To assign different USERIDs to different command categories — for example, a low-authority USERID for DISPLAY commands and a higher-authority USERID for action commands — deploy copies of CMDLIST under distinct names (such as CMDLDISP and CMDLOPER) and define a separate STARTED-class profile for each. The OpCon event definition references the chosen name as the REXX procedure.

For the full mechanism — including the XPSDYNAM table — that applies to every REXX and Operator Command event, see STARTED class — dynamic event address space USERID.

Limitations​

  • Quiet-period heuristic. getmsg returns when the response queue is idle for 1 second. Commands that produce delayed output (some START, async DB2/IMS commands) may exit before all lines arrive. Edit the exec to increase the timeout or add a hard wait if needed.
  • No WTOR capture. Commands that issue a Write-To-Operator-with-Reply (WTOR) are not handled — the reply prompt goes to the operator console, not to the EMCS message queue.
  • Line-by-line, not screen-formatted. Responses are captured in the order they are routed by MCS. Commands like D A,L preserve line order but not the console-screen geometry that interactive operators see.
  • Single USERID per exec name. All invocations of a given REXX procedure run under the same USERID — the one assigned by the SAF STARTED-class lookup for that exec. To vary the USERID by purpose, deploy aliases under different names (see Authorization).
  • Dataset path is hardcoded. Mode 2 always opens OPCON.COMMANDS as a fully qualified name. To use a site-specific name, edit the exec.

Customizing​

The sample is intentionally minimal so you can fork it. Common customizations:

  • Increase the getmsg timeout (5th argument) for commands with delayed output.
  • Filter responses (e.g., drop heading lines, summarize counts).
  • Chain conditional commands (issue command B only if command A's output contains a string).
  • Loop over a range of values.
  • Change cmddsn to a site-standard library, or accept it as a parameter.

Copy cmdlist.rexx to a new name in your SYSEXEC library before modifying — keep the shipped sample untouched so future LSAM upgrades don't overwrite your changes.

Example — Display system time at a scheduled point
  1. Copy cmdlist.rexx into the LSAM's SYSEXEC library.
  2. In OpCon, define a REXX event:
    • Procedure: CMDLIST
    • Parameters: % D T
  3. Schedule the event.
  4. After it runs, retrieve the event's SYSTSPRT through JORS to see the IEE136I response.

See Also​