EXEC Interface Block (EIB)
EIB (EXEC Interface Block) is a control block automatically created by CICS for every transaction. It contains important system-related information about the currently running transaction, such as: Transaction ID, Terminal ID, Task number, Cursor position, AID key pressed and Response codes.
Since EIB is automatically available in every CICS program, programmers can use it to retrieve important details about transaction execution and system status.
Below are the list of EIB fields available for each transaction –
| Name | Type | Length | Full Form | Description |
|---|---|---|---|---|
| DFHEIBLK | Structure | 0 | EXEC INTERFACE BLOCK | |
| EIBAID | Char | 1 | ATTENTION IDENTIFIER | Contains the last attention identifier received from terminal. |
| EIBATT | Char | 1 | ATTACH RECEIVED | Indicates the RU contains attach header data (X'FF'). |
| EIBCALEN | Half word | 2 | COMMAREA LENGTH | Contains the length of the communication area. |
| EIBCOMPL | Char | 1 | DATA COMPLETE | Indicates whether the data end reached during retrieval. |
| EIBCONF | Char | 1 | CONFIRM REQUESTED | Indicates that a CONFIRM request has been received for an APPC conversation. |
| EIBCPOSN | Half word | 2 | CURSOR POSITION | Contains the cursor position associated with the last terminal. |
| EIBDATE | 4 | DATE IN 0CYYDDD+ FORMAT, where C is the century (0=1900, 1=2000), YY is the year, DDD is the day number | Contains the date the task is started. | |
| EIBDS | Char | 8 | DATASET NAME | Contains the symbolic identifier of the last data set referred in a file control request. |
| EIBEOC | Char | 1 | EOC RECEIVED | Indicates that an end-of-chain indicator. |
| EIBERR | Char | 1 | ERROR RECEIVED | Indicates that an error has been received on an APPC conversation. |
| EIBERRCD | Char | 4 | ERROR CODE RECEIVED | When EIBERR is set, contains the error code that has been received. |
| EIBFMH | Char | 1 | FMHS RECEIVED | Indicates that the user data received or retrieved contains an FMH. |
| EIBFN | Char | 2 | FUNCTION CODE | Contains a code that identifies the last CICS command issued by the task. |
| EIBFREE | Char | 1 | FREE REQUESTED | Indicates that the application program cannot continue using the facility. |
| EIBNODAT | Char | 1 | NO APPL DATA RECEIVED | Indicates that no data has been sent by the remote application. |
| EIBRCODE | Char | 6 | RESPONSE CODE | Contains the CICS response code returned after some specific function gets executed. |
| EIBRECV | Char | 1 | RECEIVE REQUIRED | Indicates that the application program is to continue receiving data from the facility by executing RECEIVE commands. |
| EIBREQID | Char | 8 | REQUEST IDENTIFIER | Contains the request identifier assigned to an interval control command by CICS. |
| EIBRESP | Full word | 4 | INTERNAL CONDITION NUMBER | Contains a number corresponding to the RESP condition that occurred. |
| EIBRESP2 | Full word | 4 | MORE DETAILS ON SOME RESPONSES | Contains more detailed information that can help explain why the RESP condition occurred. |
| EIBRLDBK | Char | 1 | ROLLED BACK | Indicates rollback. |
| EIBRSRCE | Char | 8 | RESOURCE NAME | Contains the symbolic identifier of the resource being accessed by the latest executed command. |
| EIBSIG | Char | 1 | SIGNAL RECEIVED | Indicates that SIGNAL has been received. |
| EIBSYNC | Char | 1 | SYNCPOINT REQUESTED | Indicates that the application program must take a sync point or terminate. |
| EIBSYNRB | Char | 1 | SYNC ROLLBACK REQ'D | Indicates that the application program should issue a SYNCPOINT ROLLBACK command. |
| EIBTASKN | 4 | TASK NUMBER | Contains the task number assigned to the task by CICS. | |
| EIBTIME | 4 | TIME IN 0HHMMSS FORMAT | Contains the time at which the task is started. | |
| EIBTRMID | Char | 4 | TERMINAL IDENTIFIER | Contains the symbolic terminal identifier of the principal facility associated with the task. |
| EIBTRNID | Char | 4 | TRANSACTION IDENTIFIER | Contains the symbolic transaction identifier of the task. |
Short Examples -
Scenario - COBOL program example demonstrates how to use CICS HANDLE AID to process user input based on AID keys.
...
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WS-TRANS-ID PIC X(4).
01 WS-TERMINAL-ID PIC X(4).
01 WS-TASK-NUMBER PIC 9(7).
..
PROCEDURE DIVISION.
MOVE EIBTRNID TO WS-TRANS-ID.
MOVE EIBTERMID TO WS-TERMINAL-ID.
MOVE EIBTASKN TO WS-TASK-NUMBER.
...
...Retrieves the transaction ID (EIBTRNID) and stores it in WS-TRANS-ID. Retrieves the terminal ID (EIBTERMID) and stores it in WS-TERMINAL-ID. Retrieves the task number (EIBTASKN) and stores it in WS-TASK-NUMBER.