SVCSCREEN

In a non-CICS environment, z/OS® Debugger requires SVC screening for the following situations:

  • Invoking z/OS Debugger by using EQANMDBG to debug programs that start outside Language Environment® including non-Language Environment COBOL programs.
  • Debugging programs that do not run in Language Environment and are started by programs that begin in Language Environment.
  • Debugging LangX COBOL programs.
  • Detecting services such as MVS LINK, LOAD, DELETE and ATTACH.

If you need to run z/OS Debugger in any of the following situations, you must specify the actions that z/OS Debugger must take regarding SVC screening:

  • Start z/OS Debugger by using EQANMDBG in an environment that already uses SVC screening.
  • Run z/OS Debugger when debugging programs that do not run in Language Environment and are started by programs that begin in Language Environment.
  • Run z/OS Debugger when debugging LangX COBOL programs.
  • Run z/OS Debugger when you need to detect services such as MVS LINK, LOAD and DELETE.
  • Run z/OS Debugger when you debug subtasks within a multi-tasked application, where subtasks are started by using the ATTACH assembler macro.
  • Run z/OS Debugger in a situation that requires SVC screening and SVC screening is already in use by a program with which z/OS Debugger supports MERGE SVC screening as described by the MERGE operand that follows.

The following diagram describes the syntax of the SVCSCREEN command:

Read syntax diagramSkip visual syntax diagramEQAXOPTSVCSCREEN, ONOFF(OFF,QUIET),CONFLICT=OVERRIDENOOVERRIDE,NOMERGEMERGE=(COPE)
ON
Indicates that you want z/OS Debugger to use SVC screening in order to support MVS LOAD, DELETE, and LINK SVCs.
OFF
Indicates that you want z/OS Debugger to not use SVC screening. z/OS Debugger will not know about programs started through MVS LOAD, DELETE, and LINK SVCs. If you start z/OS Debugger by using the EQANMDBG program, the OFF setting is ignored.
QUIET
Suppresses message EQA2458I, which is written to the z/OS Debugger log when SVC screening is disabled by default.
CONFLICT=
Specifies what you want z/OS Debugger to do when ON is specified or defaulted and SVC screening is already used by another program.
OVERRIDE
Indicates that you want z/OS Debugger to override the current SVC screening and take control of SVC screening.
NOOVERRIDE
Indicates that if SVC screening is already in use, z/OS Debugger does not initiate SVC screening and proceeds as if OFF were specified.
NOMERGE
Indicates that SVC screening is not to be merged with SVC screening used by any other product. NOMERGE is the default.
MERGE
Indicates that when SVC screening is already being used by another program when z/OS Debugger starts, z/OS Debugger saves the current SVC screening environment, then enables SVC screening for both z/OS Debugger and the other program. When z/OS Debugger terminates, it restores the original SVC screening environment.

Currently, z/OS Debugger supports the MERGE command with only one other program: COPE.

If you specify the MERGE command and z/OS Debugger does not recognize the program that is using the SVC screening, the MERGE command is ignored and z/OS Debugger starts based on the value of the CONFLICT option.

MERGE=(COPE)
If COPE is active, z/OS Debugger saves the current SVC screening environment, then enables SVC screening for both z/OS Debugger and COPE. When z/OS Debugger terminates, it restores COPE's SVC screening environment.

If COPE is not active, z/OS Debugger starts based on the value of the CONFLICT option.

The default parameters for the EQAOPTS SVCSCREEN command is one of the following situations:

  • If z/OS Debugger is started by using the EQANMDBG program: SVCSCREEN,ON,CONFLICT=NOOVERRIDE,NOMERGE
  • If z/OS Debugger is started by any other method: SVCSCREEN,OFF,CONFLICT=NOOVERRIDE,NOMERGE

Use Table 1 as a guide to select the appropriate suboptions.

Usage notes

  • This command does not support 64-bit programs.

Example

EQAXOPT SVCSCREEN,ON,CONFLICT=OVERRIDE,NOMERGE
EQAXOPT SVCSCREEN,OFF,CONFLICT=NOOVERRIDE,NOMERGE