CICS quick notes


  1. 2 types of application systems
a) Batch (Eg. Monthly Sales report) b) Online (Eg. Airline Reservation system)

  1. 3 different types of batch & online processing mode
  1. For Batch – Single task, Single thread, Priority in job scheduling
  2. For online – Multitask, Multithread, Priority processing

  1. CICS components are,
  1. Data communication functions
  2. Data handling functions
  3. Application program services
  4. System services
  5. Monitoring functions

  1. IEWL is used to link edit CICS programs

  1. There are 5 ways to initiate a CICS transaction initiation

  1. By press Enter key
  2. By Pseudo conversation
  3. By start command
  4. By Automatic Task Initiation
  5. By an Attention Identifier

  1. RETURN command is used to terminate and return the control to CICS region

  1. Multitasking means that the operating system allows more than one task to be executed concurrently, regardless of whether the tasks use the same program or different programs.

  1. Multithreading is a program is shared by several tasks concurrently.

  1. Reentrant program is a program which does not modify itself so that is can reenter to itself and continue processing after an interruption by the operating system

  1. A non-reentrant program is a program, which modifies itself so that it cannot reenter to itself.

  1. A quasi-reentrant program is a reentrant program under CICS environment.

  1. Response code for a CICS command is shown in EIBRCODE field.

  1. HANDLE CONDITION is used to transfer control to the specified label specified if the exceptional condition specified occurs.

Syntax: EXEC CICS HANDLE CONDITION
Condition (label)
[Condition (label)]
[ERROR (label)]
END-EXEC


  1. HANDLE CONDITION request has been made, it remains active until the end of the program or another HANDLE CONDITION request overrides it.

  1. The IGNORE condition command causes no action to be taken if the condition specified occurs in the program. No more than 12 conditions are allowed in this command.

Syntax:
EXEC CICS IGNORE CONDITION
Condition
[Condition]
END-EXEC

  1. If a negative value or out-of-range value is specified in the length field of SEND command, LENGERR will be displayed.

  1. The PUSH and POP commands are used to suspend and reactivate respectively, all HANDLE CONDITION (&HANDLE AID) requests currently in effect.

  1. Difference between HANDLE CONDITION & HANDLE AID

Handle condition will incorporate all the ABENDS.
Handle Aid condition will be useful only Attention keys

  1. Two other alternatives for HANDLE CONDITION command are NOHANDLE option and RESP option.

  1. NOHANDLE – will cause no action to be taken for any exceptional condition occurring during the execution of HANDLE condition

  1. RESP option – CICS places a response code at a completion of the HANDLE CONDITION command.

  1. GETMAIN – is used to obtain a certain amount of storage

Syntax:
EXEC CICS GETMAIN
SET (pointer-ref)
LENGTH (data-value) | FLENGTH (data-value)
INITIMG (data-value)
[NOSUSPAND]
END-EXEC

  1. FREEMAIN – is used to release the storage, which has been acquired.

Syntax:
EXEC CICS FREEMAIN
DATA (data-value)
END-EXEC

  1. The name of the program must be registered in the processing program table(PPT)

  1. A task is unit of work which is scheduled by operating system

  1. Transaction is an entity to initiate a task. The length of a transaction identifier is 1 to 4 char. It must be registered in the PCT.

  1. LINK – to pass control to another program at the lower level, expecting to be returned

Syntax:
EXEC CICS LINK
PROGRAM (name)
[COMMAREA (data-value)]
[LENGTH (data-value)]
END-EXEC


  1. XCTL – to pass control another program at the same level, not expecting to be returned. Performance is relatively better in comparison to LINK command.

Syntax:
EXEC CICS XCTL
PROGRAM (name)
[COMMAREA (data-value)]
[LENGTH (data-value)]
END-EXEC

  1. COMMAREA – Data can be passed to a called program using the commarea operation of the LINK or XCTL command. The length is specified in the LENGTH parameter of the LINK or XCTL. The maximum length is (S9(4) comp) is 65,536 bytes.

  1. RETURN – is used to return control to the next higher logical level.

Common Exceptional Condition: INVREQ & NOAUTH

Syntax:
EXEC CICS
[TRANSID (name)]
[COMMAREA (data-area)]
[LENGTH (data-value)]
END-EXEC

  1. The LOAD command - load a program or a table which is independently compiled or assembled, link-edited and registered in PPT. Useful for loading a table dynamically. Table can be coded in Assembler.

CEC: NOAUTH, PGMIDERR

Syntax:
EXEC CICS LOAD
PROGRAM (name)
[SET (pointer-ref)]
[LENGTH (data-value) | FLENGTH (data-area)]
[ENTRY (pointer-ref)]
[HOLD]
END-EXEC

  1. RELEASE – to release a program or table

EXEC CICS RELEASE
PROGRAM (name)
END-EXEC


  1. PPT – to register all CICS application programs and BMS maps.

  1. PCT – to register the control information of all CICS transactions. Used for identifying and initializing the transactions.

  1. READ command with INTO option is used to read a specific record specified by the key

Syntax: CEC – DUPKEY, NOTFND, LENGERR
EXEC CICS READ
DATASET (name) | FILE (name)
INTO (data-area)
RIDFLD (data-area)
LENGTH (data-value)
END-EXEC

  1. READ command with GENERIC option – to read a nonspecific record based on the generic key. When the complete information of the key is not available.

  1. READ with UPDATE command and REWRITE commands are used to update a record.

  1. UNLOCK – is used to release the exclusive control from the record.

Syntax
EXEC CICS UNLOCK
DATASET (name)
END-EXEC

40) WRITE – To write a record directly into the file. CEC: DUPREC, NOSPACE, and LENGERR

EXEC CICS WRITE
DATASET (name) | FILE (name)
FROM (data-area)
LENGTH (data-value)
RIDFLD (data-area)
MASSINSERT
END-EXEC

41) MASSINSERT in WRITE command is used to add a group of records whose keys in ascending order into a file.

  1. DELETE command is used to delete one record or a group of records from a file.

Syntax:
EXEC CICS DELETE
DATASET (name)
RIDFLD (data-area)
KEYLENGTH (data-value)
GENERIC
END-EXEC

  1. Delete after READ/UPDATE
  2. Direct delete
  3. Group record delete

  1. STARTBR – to establish a browse starting position for a file.

EXEC CICS STARTBR
DATASET (name) | FILE (name)
RIDFLD (data-area)
GTEQ
END-EXEC

CEC: DSIDERR, NOTFND


  1. READNEXT – To read a record of a file sequentially forward
CEC: DUPKEY, ENDFILE, and LENGERR

Syntax:
EXEC CICS READNEXT
DATASET (name) | FILE (name)
INTO (data-area)
LENGTH (data-value)
RIDFLD (data-area)
REQID (data-value) – for multiple browse operation
END-EXEC

  1. READPREV – To read a record of a file backward
CEC: NOTFND, INVREQ
Syntax:
EXEC CICS READPREV
DATASET (name) | FILE (name)
INTO (data-area)
LENGTH (data-value)
RIDFLD (data-area)
END-EXEC

  1. RESETBRTo reestablish another starting point within the same browse operation against the same file. Without issuing of the ENDBR only the RESETBR makes it possible to reposition the dataset for a new browse operation. The syntax is similar to STARTBR. CEC: INVREQ

  1. ENDBR – To terminate the browse operation which is initiated by the prior STARTBR command. There must ENDBR for each STARTBR.

Syntax:
EXEC CICS ENDBR
DATASET (name)
END-EXEC

  1. REQID parameter is used for multiple browse operation.

  1. RBA (Relative Byte Address) option is used to read a VSAM/ESDS file sequentially forward and backward.

  1. FCT – To register control information of all files which are used under CICS.

  1. TCP – provides communication services between user-written application programs and terminals using the information defined in the TCT.






  1. ISSUE PRINT - used to make a hard copy print of a screen on a printer

Syntax
EXEC CICS ISSUE
PRINT
END-EXEC

  1. ISSUE COPY – used to copy a screen image of the terminal into another terminal.

Syntax
EXEC CICS ISSUE
COPY
TERMID (name)
END-EXEC


  1. AID (Attention Identifier) – indicates which method the terminal operator has used to initiate the transfer of information from the terminal device to CICS.

  1. HANDLE AID – To specify the label (i.e. Paragraph name) to which control is to be passed when the specified AID is received.

Syntax
EXEC CICS HANDLE AID
Option (label)
END-EXEC

  1. NMDS (NATIVE MODE DATA STREAM) – mixture of Buffer control characters and text data

  1. NMDS – both device dependent and format dependent.

  1. BMS (Basic Mapping Support) – used to define the screen.

  1. Two types of maps – Physical (stored in load library) & symbolic maps (stored in copy library).

  1. Representation of one screen format is called MAP. A group of maps, which are linkedited together, is called MAPSET.

  1. Map definition macros

DFHMSD – To define a mapset

TYPE= To define the map type
DSECT For symbolic map
MAP For Physical map
&SYSPARM For special assembly procedure
FINAL To indicate the end of a mapset coding

MODE=
IN For the input map
OUT For the output map
INOUT For the input/output map

LANG= To define the language (COBOL, ASM, PLI or RPG)

STORAGE=AUTO To acquire a separate symbolic map area for each mapset

TIOAPFX=YES

CNTL=
FREEKB To unlock the keyboard
FRSET To reset MDT to zero. Useful when the same map is repeatedly
Sent to terminal for the data entry
ALARM To set an alarm at screen display time
PRINT To indicate the mapset to be send to printer

TERM=type

SUFFIX=nn

DFHMSI – To define a map

SIZE=(LL, CC), LINE=N, COLUMN=M, JUSTIFY=LEFT

DFHMSF – To define a field
ASKIP - AUTOSKIP. Data cannot be entered into the field
PROT - Protect a field
UNPROT - Unprotect a field

NUM - Numeric field

BRT - Bright display
NORM - Normal display
DRK - Dark display. Password field

IC - Insert cursor. IC is specified in more than one field of a map, the cursor will be placed in the last field.

FSET - Field set

  1. MDT (Modified Data Tag) – one bit of attribute character. 0 – field has not been modified by the terminal operator. 1 – field has been modified by the operator. MDT reduces the amount of data traffic in the communication line.

  1. Format of symbolic map

Name+L - Output for dynamic cursor positioning
Name+F - Flag byte
Name+A - Attribute byte for both i/p and o/p
Name+I - Input field
Name+O - Output field

  1. Skipper – unlabeled 1-byte field with the autoskip attribute
Stopper – unlabeled 1-byte field with the protect attribute

  1. RECEIVE MAP – used to receive a map from a terminal

EXEC CICS RECEIVE
MAP (name)
MAPSET (name)
END-EXEC

Validity checking after the completion of the RECEIVE MAP command:
  • check the fieldname+L (for zero or positive value)
  • check the fieldname+I (for low values or space)



  1. SEND MAP – used to send a map to a terminal

EXEC CICS SEND
MAP (name)
MAPSET (name)
[CURSOR]
[ERASE]
END-EXEC

Options: ERASE – To erase the current map before the map specified appears on the screen.
ERASEUP – To erase all the unprotected fields.
FREEKB – To free the keyboard
ALARM – To make an alarm sound
FRSET – To reset MDT to zero

DATAONLY – Only application pgm data in the symbolic map is to be sent to the
Terminal
MAPONLY – Only the default data from the physical map is to sent to the terminal

  1. SEND CONTROL command is used by an application program dynamically establishes the device control options without actually sending a map.

EXEC CICS SEND
CONTROL
[CURSOR (data-value)]
[ERASE | ERASEUP]
[FREEKB]
[ALARM]
[FRSET]
END-EXEC

  1. FEATURE= (UCTRAN, ----) – specify in TCT, CICS translates all lower-case characters into upper-case characters.

  1. TERMINAL ASIS in RECEIVE command is used to translates all lower-case to upper case characters.

  1. SEND TEXT – used to send a single-stream text to a terminal. Used only for a single page screen. ACCUM option is used send to more than one page screen.

EXEC CICS SEND TEXT
FROM (data-value)
LENGTH (data-value)
[HEADER (data-value)]
[TRAILER (data-value)]
[ACCUM]
[ERASE]
END-EXEC

  1. Transient Data Queue (TDQ) – 1 to 4 char destination id registered in Destination control table.

Intrapartition TDQ – a group of sequential records which are produced and processed by the same and/or different transactions within a CICS region. TDQs are stored in only one physical file in a CICS region.

Extrapartition TDQ - a group of sequential records which interfaces between the transactions of the CICS region.



  1. WRITEQ TD – To sequentially write a record in a TDQ. Valid for both the TDQ.

EXEC CICS WRITEQ TD
QUEUE (name)
FROM (data-area)
LENGTH (data-value)
END-EXEC

  1. READQ TD – To sequentially read a record in a TDQ. Valid for both the TDQ.

EXEC CICS READQ TD
QUEUE (name)
INTO (data-area)
LENGTH (data-value)
END-EXEC

  1. DELETEQ TD - To delete an Intrapartition TDQ. Not valid for the Extrapartition TDQ.

EXEC CICS DELETEQ TD
QUEUE (name)
END-EXEC

  1. Automatic Task Initiation (ATI) is a facility through which a CICS transaction can be initiated automatically. TDQ is read destructive.

  1. Temporary Storage Queue (TSQ) – queue of stored records (data). Created and deleted dynamically by the application program. Queue id 1 to 8 bytes. Written in main or auxiliary storage.

  1. WRITEQ TS – To write or rewrite a record (item) in a TSQ.

EXEC CICS WRITEQ
QUEUE (TSQ name)
FROM (data-name)
LENGTH (length)
ITEM (item name)
MAIN/AUX
END-EXEC

  1. READQ TS – To read a particular record (item) of a particular TSQ.

EXEC CICS WRITEQ
QUEUE (TSQ name)
INTO (data-name)
LENGTH (length)
ITEM (item name)
END-EXEC

  1. WRITEQ with REWRITE option is used to rewrite a record (item) of a TSQ, which has been read.

EXEC CICS WRITEQ
QUEUE (TSQ name)
FROM (data-name)
LENGTH (length)
ITEM (item name)
REWRITE
MAIN
END-EXEC


  1. TSQ with the MAIN option are nonrecoverable after a system crash or transaction ABEND.

  1. Scheduled Transaction Initiation (STI) – certain CICS transactions can be initiated automatically at the scheduled time or interval.

  1. DELAY – To delay the processing of a task of the specified time interval or until the specified time.

EXEC CICS DELAY
INTERVAL (time)
END-EXEC

  1. SUSPEND command is used to suspend a task.
EXEC CICS SUSPEND
END-EXEC

  1. ENQ – used to gain exclusive control over a resource.
DEQ – used to free the exclusive control from the resource.

EXEC CICS ENQ
RESOURCE (QID)
END-EXEC

EXEC CICS DEQ
RESOURCE (QID)
END-EXEC

  1. SYNCPOINT command – used to terminate the task automatically

EXEC CICS SYNCPOINT
Option
END-EXEC

  1. Cold Start – CICS and system control tables will be completely initialized irrespective of the previous system activities.

  1. Warm Start – CICS will start itself with certain system information and resources carried over from the previous CICS execution, which has been completed normally.

  1. Emergency Start – CICS execution has been abnormally terminated, an emergency system restart will take place. All these are specified in SIT as START=C/W/E.

  1. Addressing mode Address Space
24-bit addressing 15 MB
31-bit addressing 2 GB


  • CESN – To sign on into the cics region

  • CESF - To sign off from the cics region. (Press pf10)

  • NEWC pgmname

  • XPED pgmname

  • Shift + pagedown to Online to batch region.

  • CEMT I tra() – To trace Transid

  • CEMT I Prog() – To trace a program

  • CEMT I file(file name) – To identify file details

  • CECI SEND MAP mapname.

  • CECI READ DATASET (name) – To check the syntax command

  • CEBR – is a CICS supplied transaction, which browses TSQ.

  • n$in – To verify the Transid and programs

  • XPSP – to release the program from xped.
Opt: 9 & P.
Or ceci rel prog ()

MAPR commands


91) To copy a map from production to corresponding region

COMMAND === TSO MAPRCOPY

92) To view, modify and test a map

From MISOT3 region, in the command prompt type MAPR

93) To compile & create a map file (i.e. symbolic map)

From command prompt

====== TSO MOMAPR


No comments :

Post a Comment

Note: Only a member of this blog may post a comment.