If we want to change any status then just go to that option and type the first letter. For example if we want to open the file just go to Clo and type O in the place of Clo. The status will change to Ope open provided the Physical file we mentioned in Dsn is existing and has consistent properties with those defined in the region. When we want to allocate a different physical file then follow the below steps:. Change the status of the file to Clo and Disable the file.
When you do this, check the message that pops up on to the right of the file name. It should be normal. Once this is done, go to Dsn and type the name of the physical file name you want to allocate in place of the existing file name.
Now again change the status to Ope and Ena from Clo and Dis. If the file is existing and has consistent properties you will see the message as normal to your right. Note that even if the the file does not exist, the status can be changed to Ena from Dis but it will give an error when you are trying to open the file. Ass tells us that the program is written in Assembler. Pro tells us that this is a program. Ena tells us that this program is enabled. This can also be Dis Disabled.
For us to execute any program its status should be enabled. If you want to see the detailed description, place your cursor on the resource name or its status fields and press Enter. You will be able to see the detailed descriptions for that resource. This is true for all resources. Pri tells us the priority of the transaction.
Higher the value, least is the priority. Pro tells us the name of the program that is associated with this transaction. Ena tell us that the status is enabled. Physical Map is a load module in the load library which contains information about how the map should be displayed.
A Symbolic Map is a Copy book in the library. It has all the named fields. The application programmer uses these fields to read and write data into the map. For an unprotected named field, in a map, if we have specified a length of 10, this means that the name field can take values whose length cannot exceed But when you display this map using CICS and start entering values for this field on the screen, we can enter more than 10 Characters, i.
To prevent this, we use Skipper field or stopper field. A Skipper field would generally be an Unnamed field of length 1, specified after a named field. If we place a skipper field after the named unprotected field, then while entering the value, once the specified length is reached, the cursor will automatically position to the next unprotected field. If we place a stopper field after the named unprotected field, then while entering the value, once the specified length is reached, the cursor will stop its positioning.
The attribute byte of any field stores information about the physical properties of the field. The following diagram and the table explain the significance of each bit. MDT is a flag which holds a single bit. It specifies whether the value is to be transferred to the system or not. The send map command writes formatted output to the terminal.
It is used to send the map to the terminal from the application program. The following table lists the parameters used in a send map command along with their significance. It is the name of the map set that contains the mapname.
The mapset name is needed unless it is the same as the map name. It means that no data from your program is to be merged into the map and only the information in the map is transmitted. We use it to modify the variable data in a display that has already been created. Only the data from your program is sent to the screen. The constants in the map are not sent. Flag Reset turns off the modified data tag in the attribute byte for all the fields on the screen before what you are sending is placed there.
It can be used to position the cursor on the terminal screen. Cursor can be set by moving -1 to the L part of the field and then sending the map. It causes the printer to restore the paper to the top of the next page before the output is printed. Any application program would require an interface to interact with the CICS. EIB contains the information required during the execution of a program.
If we code these COBOL verbs, it will not give any compilation error, but we may get unpredictable results. The EIB is unique to a task and it exists for the duration of the task. It contains a set of system related information corresponding to the task. It contains information about transaction identifier, time, date, etc. While executing non-conversational programs, no human intervention is required. All the necessary inputs are provided when the program is started.
They are similar to batch programs that run in the batch mode. So in CICS, they are rarely developed. Sending a message to the terminal and receiving a response from the user is called a conversation. The time taken by user to respond is known as Think Time. This time is considerably high, which is a major drawback of Conversational programs. As of now, we have covered non-conversion and conversion programs.
Conversion programs have a major drawback as their think time is considerably high. To overcome this problem, pseudo-conversion programming came into the picture. We will now discuss more about pseudo-conversion programs. So we can utilize the resources in a pseudo-conversion program till the user gives the input. When the input is received, it is processed and the output is displayed. The important point to note in pseudo-conversation is passing of data between every task. We will discuss about the techniques for passing data.
It is used to pass data from one program to another program. The programs can exist in the same transaction or in different transaction also. After sending the map, the task ends and waits for the user response. At this stage, the data needs to be saved, because though the task has ended, the transaction has not. When this transaction is to be resumed, it would require the prior status of the task. User enters the input. The resources are best utilized. Resources are released as soon as the program is suspended temporarily.
When the following unconditional return statement is issued, the task and the transaction program is terminated. When the following conditional return, i. The next transaction starts when the user presses an AID key. EIBAID is one byte long and holds the actual attention identifier value used in the input stream. One way is to specify the screen position relative to line and column number in the CURSOR option on the send map command. Other way is to move -1 to the symbolic map variable suffixed with L.
While sending a map, if we want to have different attributes for a field other than that is specified in the map, then we can override that by setting the field in the program. It is provided by CICS.
The attribute required can be chosen from the list and moved to the symbolic field variable suffixed with 'A'. CICS allows us to access file data in many ways. Most file accesses are random in online system as the transactions to be processed are not batched and sorted into any kind of order. It also allows us to access data using database managers.
Form File 2. Visual Basic Text Form 3. ADL Form 5. Fallout Graphics File 6. AccountEdge Form 7. Painter Frame Stack File.
Microsoft Visual Studio Corel WordPerfect Microsoft Visual Basic 6. Microsoft Notepad. Other text editor. Each command could be achieved by executing a series of CICS macros.
This feature of operating system allows more than one task to be executed concurrently. The task may be sharing the same program or using different programs. The CICS schedules the task in its own region. This feature of the operating system allows more than one task to be executed concurrently sharing the same program. For multi-threading to be possible, an application program should be a re-entrant program under the operating system or a quasi-reentrant under the CICS. A re-entrant program is one which does not modify itself and can re-enter in itself and continue processing after an interruption by the operating system.
0コメント