CICS Overview by Pai

7/27/2019 CICS Overview by Pai

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CICS

Customer Information Control

System


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Version 2.1


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Day-wise Schedule

Day 1 Introduction To CICS

System Components

Data Communication Operation in CICS

Characteristics of CICS

Command Level Programming

CICS COPY BOOKS

Day 2 BMS Programming Considerations

Exceptional Conditions

Terminal Control Operations


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Day-wise Schedule

Day 3 Interval Control Operations

Program Control Operations

File Control Operations

Day 4 Advanced File Control Operations

Temporary Storage Control

CICS transactions

Day 5 CICS transactions continued

Assignment Completion


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Introduction To CICSFeature Batch On-Line

Data Collection Off-Line On-LineInput Sequential In Batch Random

Job Schedule At specific intervals Instantaneous

Resources Not Sharable Sharable

Response Time Not Critical Critical

Output In Printed Format On the Terminal

Security Simple Complex

Recovery Simple Complex

Information Not always current Always current

Updation In Batch Immediate


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Introduction To CICS

Interactive Programs Data Entry Program

Inquiry Program

File Maintenance Program

Menu Program

Interactive System Considerations

Shared Files

Response Time Security

Recovery


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CICS acts as an interface between the Operating

system and application programs

Application

Program

CICS

Op. System


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CICS System Concept

Data-Communication Functions

Data Handling Functions

Application Program Services

System Services

Monitoring Functions


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Operating System (MVS/XA)

Database Data Access Telecommunication

Access Method Method Access Method

(DL/I, DB2) (VSAM, (VTAM, TCAM,Data Storage BDAM) BTAM)

CICS/MVS Terminals

System Services

Data-handling Monitoring Data-Comm.

Functions Functions Functions

Application

Program Services

CICS Application programs (COBOL, PL/I, Assembler)

Other

Systems


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Features Of CICS

DB/DC

Multiprogramming Multitasking

Scheduling


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System Components

Management Modules

Tables

Control Blocks


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System Components

Management Modules Are the CICS/MVS program that interface between the

operating system and the application program.

Each management module performs a particular function.

Tables

Defines the CICS/MVS systems environment.

The tables are functionally associated with the managementmodules.


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System Components

Control Blocks

Contain system type information


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Management Modules

TerminalControlBasic

MappingSupport

ProgramControl

TaskControl

IntervalControl

TransientData

ControlTemporaryStorageControl

JournalControl

StorageControl

DumpControl

TraceControl

FileControl

Nucleus


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Management Modules

Terminal Control program Management

Module (TCP)

TCP is CICS interface to telecommunication access methods

(VTAM/TCAM)

Transfers data between the application program and the

terminal

Handles hardware communication requirement

Requests initiation of the new tasks

BMS is an interface between application program and

Terminal Control program management module.


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Management Modules

Task control Program Management Module(KCP)

Creates a task for the transaction requested

Checks the validity of the transaction-id and the authority of

the operator.

Allocates processor time among the tasks

Keeps control of the status of all CICS tasks being

processed concurrently

Transaction request can be made either

By entering transaction Id at the terminal

By another CICS transaction


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Management Modules

Program Control Program ManagementModule (PCP)

Manages the flow of control within task

Responsible for locating application program and if necessaryload them into storage for execution.

Also responsible for transferring control to the program and

returning control back to CICS

Uses PCT and PPT table to perform its actions.

PCP knows if there are any tasks currently using the same

program, from the value of USE COUNTER in PPT.


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Management Modules

File Control program Management Module

(FCP)

Manages file processing activities of each application

program FCP makes use of a table called File Control Table (FCT)

FCT includes an entry for each file that is to be used during

the operation of CICS.

Thereby freeing application programmer from defining thephysical organization and other file attributes.

Provides exclusive control during the updation of a record by

a task


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Management Modules

Storage Control Program Management

Module (SCP)

Maintains full control over the virtual storage

Acquires, controls and releases dynamic storage during

execution of a task

Allocation of main storage is automatic Controls requests for the main storage


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Tables

The tables define the resources that CICS controls

Each table is associated with corresponding

management modules

The tables are brought into storage when CICS is

initialized.


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Tables

Some of the important tables in CICS/MVSare:

FCT: File Control Table PCT: Program Control Table

PPT: Processing Program Table

TCT: Terminal Control Table

DCT: Destination Control Table

SIT: System Initialization Table


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Control Blocks

Dynamically created by CICS when needed

Accessed by CICS modules during execution of tasks

Released when no longer needed

Example: Execute Interface Block (EIB), Task ControlArea


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Data Communication Operation In

CICS Terminal Control Program Management Module

(TCP)

Basic Mapping Support (BMS)

Batch Data Interchange (BDI)

Data Comm nication Operation In


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Data Communication Operation In

CICS Terminal Control Program Management Module (TCP)

Is the basic method for communicating with devices

BMS and BDI use terminal control facilities when invoked by an application

program

Basic Mapping Support (BMS)

Interface between TCP and application program

Provides commands and options that can be used to format data in a standard

manner It converts data streams provided by the application program to conform to the

requirements of devices.

Facilitates development of device & format independent programs


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Basic Mapping Support

BMS removes the responsibility of formatting the

screen from the application program.

BMS places the data with necessary controlcharacters in a TIOA.

It allows repositioning of fields without modifying

application program BMS makes the application program Format

Independent and Device Independent


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Format Independence

Application programs are written without concern for

physical position of data fields within a display

In an application program symbolic labels are used to

refer the fields

BMS relates the label to the actual position in the

display


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Device Independence

Application programs can be developed without any

concern for physical characteristics of the terminals

BMS prepares the message based on the terminal type

being used


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BMS Maps

A Screen defined through BMS is called a

map.

A mapset contains a single or multiple maps

defined for one terminal type.

Two ways of defining maps

CICS supplied macros

Screen Definition Facility (SDF)

Map represents BMS coding for a screen, and

Mapset represents a load module


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Map Generation

Design Screen

Code Map

Assemble

Symbolic MapPhysical Map

-Load Library

-Contains Literals

-Source Library

-Contains Data-fields


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Physical Map

Describes display format for a given terminal type It includes

The format of input & output data

The fixed data such as page headings

Symbolic names of variable data-fields

The device type to which map relates.

Physical Map Generation

BMS macro coding Assembly Link-edit

Load Module LOADLIB To be used by CICS


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Symbolic Map

Defines all variable data fields

Ensures device and format independence

Used by application program which issues a COBOL COPY statementin order to include a symbolic map in the program.

Symbolic Map Generation:

BMS macro coding Assembly Symbolic map definition

COPYLIB Copied into CICS application program


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Map and Mapset

Map A representation of one screen format is called a map

One or group of maps makes up a mapset

Mapset

A group of maps, which are linkedited together is called mapset

Each mapset must be registered in PPT


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Map and Mapset

Mapset The mapset name consists of two parts as follows:

Generic Name: 1 to 7 characters

Suffix : 1 character

Application program uses only the generic name. The suffix isrequired at the mapset definition time in order to distinguish the

device types if the same mapset is used for different types of

terminals.

CICS automatically inserts the suffix depending on the terminal inuse, thereby ensuring the device independence to the application

program


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Components Of A Screen

CICS identifies screen into three components:

Mapset

Maps

Physical Map

Symbolic Map

Fields

Unnamed (Literals)

Named (Data fields)

Stopper


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Attribute Byte Format

The attribute character is always thefirst character of a field.

It occupies a character position on thescreen but appears as a blank

0 1 2 3 4 5 6 7

ProtectionIntensity MDT

Attribute Byte Bit Position :`


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Positions Functions Bit Settings

0-1 Information about bits 2 thru 7

2-3 protection 00 = Unprotected alphanumeric

01 = Unprotected numeric

10 = Protected

11 = skip

4-5 Intensity 00 = Normal

01 = Normal

10 = Bright

11 = No-display6 Must be 0

7 MDT 0 = Field has not been modified

1 = Field has been modified



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Field Protection

Unprotected

Protected

Auto-skip

Field Intensity

Normal

Bright No-display

Shift


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Modified Data Tag (MDT)

MDT is the one bit of the attribute character

If it is zero, it indicates that this field has not been modified by the

terminal operator

If it is one, it indicates that this field has been modified by the operator.

Only when it is ON, will data of the field be sent by the terminal to

the application program.

Effective use of MDT reduces the data traffic in the communication

line, thereby improving performance significantly


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Modified Data Tag (MDT)

Following are the three ways to set MDT ON:

By data-entry

By setting attribute byte in the physical map

By moving MDT attribute in the application program


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Map Definition Macros

Available Macros

DFHMSD

DFHMDI

DFHMDF

General Format

Col1 Col 10 Col16 Col17 Col72

Symbolic Opcode Parameter(s) Contd

Name Additional parameters Char.


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Example

1 10 16 17 72

MENU DFHMSD TYPE=&SYSPARM X

MODE=INOUT,

LANG=COBOL..


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Order of Map-Code

PRINT NOGEN ----> Assembler Command

Label DFHMSD ----> Mapset Definition

Label DFHMDI ----> Map Definition

DFHMDF ----> Field Definition

Label DFHMDF ----> Field Definition

Map1 |

|

|

DFHMDF

Map2 DFHMDI

DFHMDF

||

DFHMDF

DFHMSD Type = Final --> Mapset Definition

END -------------------> Assembler command


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DFHMSD Macro

End of Mapset Definition

DFHMSD TYPE=FINAL


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DFHMDF Macro

Function

The DFHMDF macro is used to define a field in map and its characteristics. The DFHMDF macro can be issued as many times as you wish within

one DFHMDI macro.

Label DFHMDF POS=(line | column)

[, LENGTH=number]

[, JUSTIFY=([LEFT | RIGHT])

[, ATTRB=(ASKIP | PROT | UPROT [, NUM]][, BRT | NORM | DRK]

[, IC][, FSET]) ]

[, HILIGHT=OFF | BLINK | REVERSE | UNDERLINE]

[, VALIDN=([MUSTFILL | MUSTENTER])

[, OCCURS=number]

*, INITIAL=value+

*, PICIN=value+*, PICOUT=value+

f b l


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Format Of Symbolic Map

A COBOL program must contain a COBOL COPY statement for eachsymbolic map definition in working storage section.

It starts with the 01 level definition of FILLER PC X(12), which is the

TIOA prefix created by TIOPFX=YES of the DFHMSD macro.

Each symbolic map field consists of sub-fields. Each sub-field has a

different suffix.


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Format Of Symbolic Map

nameL: Indicates length of the data entered in the field.

nameF: It sets to ON when field gets modified

nameA: The attribute byte for input/output field

nameI: The input data field.

nameO: The output data field.

Example
http://localhost/var/www/apps/conversion/tmp/scratch_3/MAPS.CPYhttp://localhost/var/www/apps/conversion/tmp/scratch_3/MAPS.CPY


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Characteristics Of CICS

Multithreading

Quasi-Reentrancy

Pseudo-Conversational Programming

Transaction Driven

Quasi-Reentrant Program


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Q g

VirtualStorage

Program A

Object Code

Program A

Working

Storage

(User1)

Program A

Working

Storage

(User2)

User 1

Running

Program A

User 2

Running

Program A


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CICS Program Development

Macro Level Programming


CICS C d F


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CICS Command Format

CICS commands are embedded into the Host language, e.g. in the Procedure

Division of COBOL program.

CICS commands in a COBOL program are delimited by

EXEC CICSEND-EXEC.

EXEC CICS is coded in margin B of COBOL program.

The command level translator replaces these statements by COBOL MOVE

statements followed by COBOL CALL statement.

The translated module is compiled & linked to produce an executable load

module.

The translator also includes copy books into program.


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CICS Command Format

EXEC CICS Function[option(argument)

option(argument)

--------

--------

]

END-EXEC.

C d L T l t


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Command Language Translator

COBOL Source

Program

Translator

Translated Source

Program

COBOL Compiler

Object Module Link Edit Load Module


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COBOL/CICS Program Structure

IDENTIFICATION DIVISION.PROGRAM-ID.

ENVIRONMENT DIVISION.

DATA DIVISION.

WORKING-STORAGE SECTION.

Variable declaration

File layoutSymbolic map

Copy books

DFHEIVAR

LINKAGE SECTION.

DFHCOMMAREA

EIBBLOCK

BLL CELLS

PROCEDURE DIVISION.

COBOL/CICS P St t


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COBOL/CICS Program Structure

The following COBOL statements are prohibited ina CICS application program:

ACCEPT, CURRENT-DATE, DATE DAY, DISPLAY, EXHIBIT,

STOP RUN, TRACE

Any I/O statements (OPEN, CLOSE, READ, WRITE,

REWRITE, DELETE, START

REPORT WRITER Feature

SORT Feature

ass ng e a a us ng


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ass ng e a a us ngCOMMAREA

Passing of data from one program to another is achieved by

COMMAREA defined in working-storage section.

The receiving program will receive the data in its linkage section,

under DFHCOMMAREA.

May be used in functions like RETURN/XCTL/LINK

The length of COMMAREA must be specified in the LENGTH

parameter of the LINK or XCTL command in the calling program.

The LENGTH parameter must be defined as a half-word binary

fields (S9(04) COMP).

Called program can find length of data passed using the EIB field

EIBCALEN


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CICS COPY BOOKS

Exec Interface Block (EIB) In Linkage Section

Keeps record of system related information.

One EIB is created per task.

EIB for a task contains information about the task, which is initiated.

Copy of DFHEIBLK as EIB is automatically included in linkage section of application

program during translation.

Program can only access data using EIB field names.

User should not update data in EIB fields.

CICS COPY BOOKS


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CICS COPY BOOKS

Some of the EIB fields are EIBAID

EIBCALEN

EIBCPOSN

EIBDATE

EIBTIME

EIBDS

EIBRCODE

EIBREQID

EIBRESP

EIBTRMID

EIBTRNID

EIBTASKN


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CICS COPY BOOKS Standard Attribute Byte List

DFHBMSCA

Constants Meaning

DFHBMPEM Printer end-of-message

DFHBMPNL Printer new line

DFHBMASK Auto-Skip

DFHBMUNP UnprotectedDFHBMUNN Unprotected & num

DFHBMPRO Protected

DFHBMPRY Bright

DFHBMDAR Dark

DFHBMFSE MDT setDFHBMPRF Protected and MDT set

DFHBMASF Auto-Skip & MDT set

DFHBMASB Auto-Skip & bright

CICS COPY BOOKS


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CICS COPY BOOKS

Installation Defined

01 Field-Attribute-Definition.

05 FAC-UNPROT PIC X VALUE ' '.

05 FAC-UNPROT-MDT PIC X VALUE 'A'.

05 FAC-UNPROT-BRT PIC X VALUE 'H'.

05 FAC-UNPROT-BRT-MDT PIC X VALUE 'I'.

05 FAC-UNPROT-DARK PIC X VALUE '


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CICS COPY BOOKS

Installation Defined Message File

01 WS-MESSAGES.05 WS-FATAL-ERROR-MSG PIC X(30) VALUE 'YOU CAN ONLY START

FROM MENU'.

05 WS-NORMAL-EXIT-MSG PIC X(30) VALUE 'SESSION ENDS HAVE A

NICE DAY'.

05 WS-INVALID-KEY-MSG PIC X(30) VALUE 'INVALID AID KEY

PRESSED'.

05 WS-NOT-UNIQUE-MSG PIC X(30) VALUE 'ISSUE NOTE NO EXISTING'.

05 WS-ITEM-NOT-FND-MSG PIC X(30) VALUE 'ITEM NOT FOUND'.

05 WS-INVALID-QTY-MSG PIC X(30) VALUE 'INVALID QUANTITY ENTERED'.05 WS-DUP-REC-MSG PIC X(30) VALUE 'DUPLICATE RECORD'.


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CICS COPY BOOKS

Attention Identifier (AID) Attention Identifier indicates which method the terminal operator

has used to initiate the transfer of information from the terminal

device to CICS

AID keys are: PF keys, PA keys, ENTER key, and CLEAR key. The EIBAID field in EIB contains the AID code of the most

recently used AID.

CICS provides the standard AID list in a form of copy library

member(DFHAID), so that a program can use this list byspecifying in the program: COPY DFHAID

CICS COPY BOOKS


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CICS COPY BOOKS

The DFHAID member contains such AID codes as:

DFHENTER: ENTER key

DFHCLEAR: CLEAR key

DFHPA1-3: PA1 TO PA3 keys

DFHPF1-24: PF1 TO PF24 keys

Example

IF EIBAID = DFHPF3

PERFORM 2100-END-ROUTINE

ELSE IF EIBAID = DFHPA1

PERFORM 2200-CANCEL-ROUTINE

ELSE IF EIBAID = DFHENTER

PERFORM 2300-NORMAL-ROUTINE

ELSE

PERFORM 2400-WRONG-ROUTINE.

Application Program


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pp gHousekeeping


An abnormal situation during execution of a CICS command is

called an exceptional condition.

Exceptional conditions can be handled using any ofthe following:

HANDLE CONDITION command

IGNORE CONDITION command

NOHANDLE option


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HANDLE CONDITION Command

EXEC CICS HANDLE CONDITION

condition(label)

*condition(label).+

[ERROR(label)]

END-EXEC.

The condition represents an exceptional condition. If a label is specified,

control will be passed to the labeled paragraph when the condition specified

occurs.

If no label is specified, it has the effect of canceling the previously set HANDLE

CONDITION request and the default action will be taken.


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The general error condition (ERROR) can be specified

within the same list to specify that all other conditions

cause control to be passed to the label specified.

Not more than 16 conditions can be specified in a singleHANDLE CONDITION command.

You can specify more than one HANDLE CONDITIONcommand in the program.



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Example:2110-RECEIVE-CHOICE SECTION.EXEC CICS HANDLE CONDITION

MAPFAIL(2110-MAP-FAIL)

END-EXEC.

EXEC CICS RECEIVE MAPSET('MENUMAP')

MAP('MENUMAP')

INTO(MENUMAPI)

END-EXEC.

GO TO 2110-EXIT.

2110-MAP-FAIL.

MOVE 'MAP FAIL SESSION ENDED' TO WS-END-SESSION-MESSAGE.

MOVE 'Y' TO WS-END-SESSION.

IGNORE CONDITION Command


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Causes no action to be taken if the condition specified occurs in the program. Control will returned to the next instruction following the command, which

encountered the exceptional condition.

The request by the IGNORE CONDITION command is valid until the subsequent

HANDLE CONDITION command for the same condition.

Format

EXEC CICS IGNORE CONDITION

condition

[condition]

END-EXEC.



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IGNORE CONDITION Command Example

EXEC CICS IGNORE CONDITION

LENGERR

END-EXEC.

EXEC CICS RECEIVE MAP(MAP1)

MAPSET(MAP1)

INTO(MAP1I)

LENGTH(80)

END-EXEC.

NOHANDLE Option


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NOHANDLE Option

This option can be specified in any CICS command, and it will cause

no action to be taken for any exceptional condition occurringduring execution of this command

Example

EXEC CICS SEND

MAP(----)MAPSET(------)

FROM(------)

LENGTH(---)

NOHANDLE

END-EXEC.


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NOHANDLE Option

RESP option If RESP option is specified in a command, CICS places a response

code at a completion of the command

The application program can check this code, then proceed to the

next processing. If the RESP option is specified in a command, the NOHANDLE

option is applied to this command. Therefore, the HANDLE

CONDITION requests will have no effect in this case.

NOHANDLE Option


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NOHANDLE Option

Example:

EXEC CICS RECEIVE

MAP(----)

MAPSET(------)

INTO(------)LENGTH(---)

NOHANDLE

RESP(WS-RESP-FIELD)

END-EXEC.

IF WS-RESP-FIELD = DFHRESP(NORMAL)

-----------

ELSE IF WS-RESP-FIELD = DFHRESP(MAPFAIL)

-----------

HANDLE AID Command


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HANDLE AID Command

This command is used to specify the label to which control is to be passed when

the specified AID is received. This is one way of substituting the EIBAID checking approach.

AID keys are PA keys, PF keys, ENTER and CLEAR key.

CLEAR and any of the PA keys do not transmit data.

Format:

EXEC CICS HANDLE AID

Option(label)

END-EXEC.

HANDLE AID Command


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Commonly used Options Any key name (PA1 to PA3, PF1 to PF24, ENTER, CLEAR

ANYKEY (Any of the above except ENTER key)

Example:

EXEC CICS HANDLE AID

PF3(2100-END-ROUTINE)

PA1(2100-CANCEL-ROUTINE)ENTER(2100-NORMAL-ROUTINE)

ANYKEY(2100-WRONG-KEY-ROUTINE)

END-EXEC.

EXEC CICS RECEIVE MAP(MAP1)

MAPSET(MAP1)INTO (MAP1I)

LENGTH(WS-MAP-LENGTH)

END-EXEC.


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Disadvantage of Using HANDLEAID Command

EIBAID
http://localhost/var/www/apps/conversion/tmp/scratch_3/handle_aid.txthttp://localhost/var/www/apps/conversion/tmp/scratch_3/handle_aid.txthttp://localhost/var/www/apps/conversion/tmp/scratch_3/handle_aid.txthttp://localhost/var/www/apps/conversion/tmp/scratch_3/handle_aid.txt


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EIBAID

The 3270 terminal transmits the AID characterto the EIBAID field of EIBAID field of EIB, at the

time of task initiation.

EIBAID can be used to find which AID key hasbeen pressed by user

CICS copy book DFHAID fields are used to

identify the key pressed

IF EIBAID = DFHAID(ENTER)

BMS Programming


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Considerations

Dynamic attribute Character Assignment

Cursor Positioning Techniques

Dynamic Attribute Character


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Assignment

COPY DFHBMSCA in Working Storage section ofthe application program.

You can assign a default attribute character in aBMS map.

For a dynamic attribute character assignment youplace the predefined attribute character to thefieldname+A of the field to which you wish todynamically assign the attribute character.

Dynamic Attribute Character


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Assignment Example


-------

COPY 'MAPSETA'.

-------

COPY 'DFHBMSCA'.

-------

PROCEDURE DIVISION.-------

MOVE DFHBMBRY TO CUSTNO-A.

MOVE DFHDMPRO TO CUSTNAME-A.

MOVE DFHDMPRO TO AMOUNT-A.

EXEC CICS SEND

MAP ('MAPNAME')

MAPSET('MAPSETA')

FROM(MAPSETAI)

END-EXEC.

h


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Static Cursor Positioning

Dynamic/Symbolic Cursor Positioning

Relative Cursor Positioning

h


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Static Cursor Positioning In this approach, you define a cursor position in a map by

placing IC in the ATTRB parameter of the DFHMDF macro

for a particular field.

When the map is sent, the cursor will appear in this field

If there are more than one field with IC specified in one map, the

last IC would be honored.

Example:

DFHMDF POS=(3,16),

ATTRB=(UNPROT, FSET, IC) LENGTH=8

C P iti i T h i


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Symbolic Cursor Positioning

In this approach, you dynamically position a cursor

through an application program using a symbolic name of

the symbolic map by placing1 into the fields length

field (i.e., filename+L) of the field where you wish to

place the cursor.

The SEND MAP command to be issued must have the

CURSOR option (without argument).

ExampleMOVE1 TO CHOICEL.

EXEC CICS SEND MAP(MAP1)

MAPSET(MAP1)

CURSOR



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Relative Cursor Positioning

In this approach, you dynamically position a cursor through an

application program using the CURSOR(data-value) option in

the SEND MAP command.

The map will be displayed with the cursor at the specified

position, overriding the static cursor position defined at the

map definition time

Data-value is calculated as: (row-1) * 80 + (column1)

Example

EXEC CICS SEND

MAP(------)

MAPSET(-------)

T i l C t l O ti


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Terminal Control Operations

RECEIVE MAP:Formatted data transfer. To receivea map.

SEND MAP:Formatted data transfer. To send amap.

RECEIVE:Unformatted data transfer. To receive a

text.

RECEIVE MAP Command (Formatted Data Transfer)


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( )

Function

This command is used to receive a map from a terminal.

At the completion of the command, the symbolic map of the

specified map will contain the data from the terminal in the

following fields per each field defined by the DFHMDF macro.

Fieldname+L

Fieldname+F

Fieldname+I



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( )

Format

EXEC CICS RECEIVE MAP(map name)

[MAPSET(mapset name)][INTO(data-area)]

END-EXEC.

d ( d f )


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Common Exceptional Conditions

MAPFAIL

If the data to be mapped has the length of zero.

If user presses the ENTER without typing data.

If map is received by pressing CLEAR or any of the PA keys.

SEND MAP Command (Formatted Data Transfer)


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Function This command is used to send a map to a terminal.

Before issuing this command, the application program must

prepare the data in the symbolic map of the map to be sent,

which has following fields per each field defined by theDFHMDF macro.

Fieldname+L

Fieldname+A

Fieldname+O



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Format

EXEC CICS SEND MAP(map name)

MAPSET(mapset name)

[FROM(data-area)][CURSOR/CURSOR(data-value)]

[ERASE/ERASEAUP]

[FREEKB] [ALARM][FRSET]

[DATAONLY | MAPONLY]

-



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( )

Example


---------------

COPY MAPA.

--------------

PROCEDURE DIVISION.

--------------

EXEC CICS HANDLE CONDITION

INVMPSZ(BIG-MAP)

END-EXEC.

---------------

EXEC CICS SEND MAP MAP(MAPA)

MAPSET(MAPA)

FROM(MAPAI)-

RECEIVE C d (U f tt d D t T f )


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RECEIVE Command (Unformatted Data Transfer)

Function This command is used to receive an unformatted message from the

terminal.

In this data transfer maps are not involved.

Format

EXEC CICS RECEIVE INTO(data-area)

LENGTH(data-value)

END-EXEC.


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Interval Control Operations

ASKTIME Command

FORMATTIME Command

ASKTIME Command


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ASKTIME Command

Function This command is used to request the current date and

time.

Also updates the EIBDATE and EIBTIME fields.

Format

EXEC CICS ASKTIME

[ABSTIME(data-area)]

END-EXEC.

FORMATTIME Command


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Function

This command is used to receive the information of dateand time in various formats.

Format

EXEC CICS FORMATTIME ABSTIME(data-area)[YYDDD(data-area)]

[YYMMDD(data-area)]

[YYDDMM(data-area)]

[MMDDYY(data-area)][DDMMYY(data-area)]

[DATESEP(data-value)]

[DAYOFWEEK(data-area)]

[DAYOFMONTH(data-area)]



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RETURN: To return to the next higher-level programor CICS.

LINK: To pass control to another program at lowerlevel.

XCTL: Tp pass control to another program at thesame level.

LOAD: To load a ro ram.

RETURN Command


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RETURN Command

Format

EXEC CICS RETURN

[TRANSID(name)

[COMMAREA(data-

area)

[LENGTH(data-

value)]]]

END-EXEC.


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LINK and XCTL Command


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Format Of LINK Command

EXEC CICS LINK

PROGRAM(name)

[COMMAREA(data-area)]

[LENGTH(data-value)]END-EXEC.



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Function of XCTL Command

Used to pass control from one application program to another

application program at the same logical level.

Format Of XCTL Command

EXEC CICS XCTL

PROGRAM(name)

[COMMAREA(data-area)]

[LENGTH(data-value)]

END-EXEC.

LINK d XCTL C d


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Common Exceptional Conditions

NOTAUTH

PGMIDERR

XCTL vs LINK


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Calling program is releasedfrom the main memory

Control is transferred to the

same logical level

Return can be to CICS or tothe application program

COMMAREA option can be

used to pass data to the

invoked program

Calling program is not released

from the main memory

Control is transferred tosame

logical level Return is always to the

application program

COMMAREA option is not

required in RETURN because

the invoked program does pass

pointer to the communication

area of the calling program.

XCTL LINK

File Control Operations (Random

)


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Access)

Supported Access Methods CICS File Control supports the VSAM and BDAM data

access method under CICS.

There are three types of VSAM file, all of which are

supported by CICS. These are as follows:

Key-Sequenced Dataset (KSDS)

Entry-Sequenced Dataset (ESDS)

Relative-Record Dataset (RRDS)

File Control Operations (RandomAccess)


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Access)

Available Commands

READ: To read a record directly

WRITE: To newly write a record

REWRITE: To update an existing record

DELETE: To delete a record

UNLOCK: To release exclusive control acquired for update

File Control Operations (RandomA )


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Access)

Special services of File Control Program

Data Independence

Exclusive control during updates

File Open/Close

READ Command Using Full Key


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Function

The READ command with the INTO option using the full

key of a record is used to read a specific record by the fullkey.

The data content of the record will be moved into the

specified field defined in the working-storage section of theprogram



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Format

EXEC CICS READ

DATASET(name)

INTO(data-area)

RIDFLD(data-area)


END-EXEC.



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Common Exceptional conditions

DUPKEY

NOTFND

LENGERR

NOTOPEN

READ Command Using GTEQOption


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Option Function

The READ command with the GTEQ option is used to

read a nonspecific record whose key is equal to or greater

than the full key data specified

Format/Example

MOVE 35 TO WK-LEN.

MOVE NY003 TO REC-KEY. =must be afull key

EXEC CICS READ

DATASET(FILE2)

INTO(FILE-IOAREA)

READ/UPDATE and REWRITECommands


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Commands Function

A combination of the READ command with theUPDATE option and the REWRITE command is used toupdate a record.

Format/Example

MOVE 35 TO WK-LEN.MOVE NY001 TO REC-A-KEY.

EXEC CICS READDATASET(FILE2)INTO(FILE-IOAREA)RIDFLD(REC-A-KEY)

UPDATE

UNLOCK Command


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The READ command with the UPDATE option

normally maintains exclusive control over the

record read until:

The record is updated by the REWRITE command.

The transaction is normally or abnormally completed.

Format/Example

EXEC CICS UNLOCK

DATASET(FILE2)

-

WRITE Command


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Function

This command is used to write a record directly into a file

based on the key specified.

Format

EXEC CICS WRITEDATASET(name)

FROM(data-area)

LENGTH(data-value)

RIDFLD(data-area)

END-EXEC.

WRITE Command


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Example

MOVE 35 TO WK-LEN.

MOVE NY004 TO REC-A-KEY.

Move symbolic map fields to the recordarea

EXEC CICS WRITE

DATASET(FILE2)FROM(FILE-IOAREA)

RIDFLD(REC-A-KEY)

-

WRITE Command


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WRITE Command


DUPREC

NOSPACE

LENGERR


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WRITE Command with MASSINSERTOption


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Option Format/Example

PROCEDURE DIVISION..

MOVE TX000 TO REC-A-KEY.

MASS-INS-LOOP SECTION.

ADD 1 TO REC-A-KEY-SEQ.

.

(Prepare the record content)

.

EXEC CICS WRITEDATASET(FILE2)

FROM(FILE-IOAREA)

RIDFLD(REC-A-KEY)

LENGTH(WK-LEN)

DELETE Command


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Function

The DELETE command is used to delete one record or a

group of records from a file.

There are three approaches to using the DELETE command

DELETE after READ/UPDATE Approach

Direct DELETE Approach

Group Record DELETE Approach

DELETE after READ/UPDATEApproach


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Approach

In this approach, the DELETE command is used

without the record key information, after the

READ command with the UPDATE option has

been completed.

The record which was read by the READ/UPDATE

command will be deleted from the file

DELETE after READ/UPDATEApproach


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Approach Format/Example

MOVE 35 TO WK-LEN.

MOVE NY001 TO REC-A-KEY.

EXEC CICS READ

DATASET(FILE2)

INTO(FILE-IOAREA)

RIDFLD(REC-A-KEY)

UPDATE

LENGTH(WK-LEN)

Direct DELETE Approach


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In this approach, the DELETE command isissued with the full key information in theRIDFLD field.

The record specified will be directly deletedfrom the file.

Format/Example

MOVE NY001 TO REC-KEY.

EXEC CICS DELETE

Group Record DELETE Approach


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In this approach, DELETE command is issued with

the GENERIC option.

A group of records, which satisfy generic key

specified, will be deleted from the file.

Format/Example

PROCEDURE DIVISION...

MOVE NY TO RE-A-KEY.

EXEC CICS DELETE

File Control Operations (Seq.

A )


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Access)

Under CICS any of the VSAM datasets can beaccessed randomly as well as sequemntially.

Available Commands: STARTBR : To establish the position of the BROWSE operation

READNEXT : To read a next record (Forward)

READPREV : To read a previous record (backward)

RESETBR : To reestablish another position for a new browse

ENDBR : To complete a browse operation.

STARTBR Command


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Function This command is used to establish a browse starting position

for a file.

Format

EXEC CICS STARTBR

DATASET(name)

RIDFLD(data-area)

[GTEQ/EQUAL]

[KEYLENGTH(data-area)

GENERIC]

STARTBR Command


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Example

WORKING-STORAGE SECTION.01 WK-LEN PIC S9(4) COMP.01 FILE-IO-AREA.

05 REC-A-KEY.10 REC-A-KEY-CITY PIC X(02).10 REC-A-KEY-SE PIC

9(03).05 REC-A-DETAIL PIC X(30).

PROCEDURE DIVISION.:

MOVE NY000 TO RE-A-KEY.

EXEC CICS STARTBR

STARTBR Command


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DSIDERR

NOTFND

READNEXT Command


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Function

The READNEXT command is used to read a record of a filesequentially forward.

Format

EXEC CICS READNEXT

DATASET(name)

INTO(data-area)


RIDFLD(data-area)

[RBA/RRN]

READNEXT Command


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Exceptional Conditions DUPKEY

ENDFILE

LENGERR

READPREV Command


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Function

This command is used to read a record of a file backward.

Format/Example


NOTFND

INVREQ

Skip Sequential Read
http://localhost/var/www/apps/conversion/tmp/scratch_3/readprev.txthttp://localhost/var/www/apps/conversion/tmp/scratch_3/readprev.txt


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This technique is used to skip records while

continuing the browse operation established

by the prior STARTBR command

For the READNEXT command, the new key for

skipping must be in the forward direction from

the current record.

Similarly, for the READPREV command, the new

key for skipping must be in the backward

Changing Direction of Browse


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g g

After the STARTBR command, the direction ofbrowse can be changed from forward to backward

by simply switching the READNEXT command to

the READPREV command, or vice versa.

The first READPREV (or READNEXT) command

after the direction change will read the samerecord as th elast READNEXT (or READPREV)

command


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ENDBR Command


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Function At physical end of file or logical end of file, the

browser operation is terminated using this command.

Format/Example

EXEC CICS ENDBRDATASET(FILE2)

END-EXEC.

Multiple Browse Operations


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p p

The multiple browse operations are used to

perform several concurrent browse operations

against the same file.

One browse operation is to be identified by the

REDQID parameter in the browse command.



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The CICS Temporary Storage Control

Program (TSP) provides the applicationprogram with an ability to store and

retrieve the data in a Temporary Storage

Queue (TSQ). Typically TSQ is used for passing of data

among transactions.

A Temporary Storage Queue is queue ofstored records (data).

It is created and deleted dynamically by an

a lication ro ram without s ecif in in



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A TSQ is identified by the queue id (1 to 8 bytes),and the relative position number called itemnumber identifies a record within a TSQ.

The records in TSQ once written, remainaccessible until the entire TSQ is explicitlydeleted.

The records in TSQ can be read sequentially ordirectly. Also records in TSQ can be updated.

TSQ in MAIN Storage or AuxiliaryStorage


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g TSQ can be written in main storage.

In this case, accessing TSQ is a fast and convenient operation.

But TSQ in this mode are not recoverable.

TSQ can also be written in auxiliary storage in a

VSAM file (DFHTEMP) established by the systemprogrammer.

It is always available to the application program, which implies

that no file open/close is required.

TSQ in this mode is recoverable.

In case of large quantity of data auxiliary storage is

preferred.



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Available Commands

WRITEQ TS: To write or rewrite a record in a TSQ

READQ TS: To read a record in a TSQ

DELETEQ TS: To delete a TSQ

WRITEQ TS Command (NoUpdate)


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p

Function This command is use to write a record (item) in a TSQ.

Format/Example

EXEC CICS WRITEQ TS

QUEUE(AttttM01)

FROM(TSQ-DATA)LENGTH(TSQ-LEN)

ITEM(TSQ-ITEM)

MAIN

WRITEQ TS Command (No

Update)


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Update)

Common Options

NOSUSPEND

AUXILIARY

Exceptional Condition

NOSPACE

READQ TS Command (DirectRead)


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Function

This command is used to read a particular record (item) of aparticular TSQ.

Format/Example

EXEC CICS READQ TSQUEUE(TSQ-QID)

INTO(TSQ-DATA)

LENGTH(TSQ-LEN)

ITEM(TSQ-ITEM)

END-EXEC.

READQ TS Command (DirectRead)


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Commonly Used Options

NUMITEMS

NEXT


QIDERR

ITEMERR

READQ TS Command (SequentialRead)


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Function

The READQ TS command can be used also for reading all records

sequentially in the queue.

But this reading should be performed based on the programmingtechniques, instead of NEXT option of the READQ TS command.

Format/Example

READQ TS Command (Sequential Read)


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*ESTABLISH HANDLE CONDITION.EXEC CICS HANDLE CONDITION

ITEMERR(TSQ-EOF)ERROR(SQ-ERROR)

END-EXEC.LOOP.

ADD 1 TO TSQ-ITEM.MOVE 200 TO TSQ-LEN.

*READ A QUEUE.EXEC CICS READQ TS QUEUE(TSQ-QID)INTO(TSQ-DATA)LENGTH(TSQ-

LENGTH)ITEM(TSQ-ITEM)

END-EXEC.

:(PROCESS A RECORD)

:GO TO LOOP.

TSQ-EOF.(EOF PROCESSING):

READQ TS Command (SequentialRead)


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Read) Note:

The sequential read of TSQ should be done By providing

ITEM.

This is a better approach than specifying the NEXT

option in the READQ TS command. If NEXT option is specified, and if other task have read

several records of the same TSQ after the last read by this

task, then this task would read a skipped record.

Therefore NEXT option should be used very carefully.

WRITEQ TS Command with REWRITEOption


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Opt o

Function

The WRITEQ TS command with REWRITE option is used

to rewrite a record of a TSQ, which has been read.

Format/Example

WRITEQ TS Command with REWRITE Option


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EXEC CICS READQ TS

QUEUE(TSQ-QID)INTO(TSQ-DATA)

LENGTH(TSQ-LEN)

ITEM(TSQ-ITEM)

END-EXEC.

:*Process data in TSQ-DATA

:

EXEC CICS WRITEQ TS

QUEUE(TSQ-QID)

FROM(TSQ-DATA)LENGTH(TSQ-LEN)

ITEM(TSQ-ITEM)

REWRITE

MAIN

END-EXEC.

DELETEQ TS Command


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Function

This command is used to delete a TSQ entirely

Format/Example

EXEC CICS DELETEQ TS

QUEUE(TSQ-ID)

END-EXEC.


QIDERR

CICS Transactions


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CSSN: Sign-On CEBR: Temporary Storage Browse

CECI: Command Level Interface

CEDF: Execution Diagnostic Facility

CEMT: Master Terminal Transaction

CEDA: Resource Definition Online

CSSF: Sign-Off

CICS Transactions

CSSN


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CSSN

Enables CICS to associate user with the terminal

Name and password should be defined in a SignoN Table(SNT)

CEBR

It browses TSQ

Content of TSQ can be displayed

CECI

It performs syntax checking of a CICS command.

If syntax is correct, it will execute the command.


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CICS Overview by Pai

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