mainframe Online Quiz - 147

In JCL, the DD (Data Definition) statement with DCB (Data Control Block) parameters uses the DD keyword to begin specifying the DCB subparameters. The DD parameter marks the start of the DCB specification which contains information about record format, block size, and other data organization attributes for the dataset.

Internal subroutines shield their variables from the main EXEC when defined with the PROCEDURE clause. This creates a local variable scope where variables defined inside the subroutine are not accessible to the calling EXEC. The correct syntax is SUBROUT1: PROCEDURE which defines the start of the subroutine with variable shielding.

To solve this question, the user needs to have knowledge of Job Control Language (JCL).

The maximum length of a single line of JCL is an important consideration while writing mainframe JCL. JCL statement can be continued onto the next line by inserting a hyphen (-) in column 72 of the JCL statement. This is referred to as JCL continuation.

Now, let's go through each option and explain why it is right or wrong:

A. 71 bytes: This option is correct. The maximum length of a single line of JCL is 71 bytes. Any JCL statement that exceeds this limit should include a continuation character (-) in column 72.

B. 60 bytes: This option is incorrect. The maximum length of a single line of JCL is greater than 60 bytes.

C. 55 bytes: This option is incorrect. The maximum length of a single line of JCL is greater than 55 bytes.

D. 80 bytes: This option is incorrect. Although 80 bytes is a common length for lines of code in other programming languages, it is not the maximum length of a single line of JCL.

The Answer is: A. 71 bytes

The DD DUMMY statement in JCL is used to allocate no space and perform no disposition processing. It's typically used to satisfy JCL syntax requirements when no actual dataset allocation is needed, or to bypass certain data definition requirements without creating physical datasets.

When a RETURN clause is used in a subroutine, the value passed back can be alphanumeric (text or numeric). This value is returned to the calling EXEC but is not stored in RC or RCODE system variables as those are used for return codes from programs, not subroutine return values. The RETURN clause supports flexible data types.

In JCL statements, the fields that contain specific values to direct and control the execution are called parameters. These include positional parameters (identified by position) and keyword parameters (identified by name). They provide the specific instructions needed for statement execution.

In REXX, PULL reads from input and stores in a variable. Then PARSE VALUE parses that variable's contents into multiple named variables. Option B correctly shows pulling into DATE then parsing DATE into DAY, MONTH, YEAR. Option A uses PARSE PULL which reads input directly but doesn't handle the parsing pattern correctly for this date format.

The ADDRESS clause in REXX directs commands to a specific host environment. ADDRESS TSO sends subsequent commands to the TSO environment. HOST TSO, HSTADDRS TSO, and EXEC TSO are not valid REXX syntax for this purpose.

In REXX, TRACE ?R enables interactive tracing/debugging mode. The '?' prefix makes trace interactive, allowing you to step through execution. TRACE R alone enables normal trace without interaction. TRACE IR and INTTRACE R are not valid REXX trace commands.

EXECIO requires the dataset to be sequential or PDS member (A is required), must be allocated to a DD name (B is required), and TSO/MVS environment (D is required). However, exclusive enqueue (DISP=OLD/NEW) is NOT required - EXECIO can work with datasets that have DISP=SHR. Option C correctly identifies the non-prerequisite.

JES2 (Job Entry Subsystem 2) uses XMIT to transmit jobs to other nodes and XEQ as a command identifier for job execution. ROUTEXEQ and OPERATOR are not standard JES2 commands in this context - OPERATOR is a console command, not a JES2-specific feature.

The S322 abend occurs when a job step exceeds its allocated CPU time parameter. The TIME parameter in the JOB or EXEC statement specifies the maximum processor time a step can use, and improper handling (setting it too low) causes this timeout-related abend.

In JES2, the LINES parameter specifies output line limits and can be used with values like DUMP (dump output), CANCEL (cancel output), and WARNING (issue warning message). ABEND is not used with LINES - it's a separate job termination action.

In JCL (Job Control Language) for IBM mainframes, the LIKE parameter copies dataset attributes (space allocation, record format, etc.) from an existing dataset. COPY and COPIES are not valid parameters for this purpose - LIKE is the standard JCL keyword.

In IBM JCL, the EXPDT parameter supports the formats yyddd (two-digit year and three-digit day) and yyyy/ddd (four-digit year and three-digit day). yyyyddd and yy/ddd are not valid formats.

In JCL, the expiration date parameter EXPDT uses the Julian date format. February 2, 1996 is the 33rd day of the leap year 1996. The valid syntax for a 4-digit year with a slash separator is EXPDT=yyyy/ddd, making EXPDT=1996/033 the correct choice.

In JCL, the RD (Restart) parameter controls automatic job restart after system failures. RD=NC (No Check) means automatic and deferred restart are disabled - the job will not restart under any circumstances without manual intervention.

RD parameter controls restart behavior: 'NC' means No Commit, which prevents both automatic and deferred restart in any form. This is the strictest setting. Other options like RNC might allow certain types of restarts under specific conditions.

For Variable Spanned (VS) records, the LRECL can exceed the BLKSIZE, but for a single block, the segment size constraints apply. The 'K' syntax is valid for specifying sizes in thousands of bytes.