IBM Mainframes

Starting with REXX

2013-01-03T10:12:00.000-08:00

Sample rexx program:

/* rexx */
Say 'hello world'

Save this in a pds member and just before the member give 'ex'... It would execute this rexx routine and give output as 'hello world'

Note: all rexx should begin with /* rexx */ in the comments... You can prefix or suffix any comment to it....

Say is equivalent to display in cobol...

PL/1 Interview Questions

2012-12-29T09:48:00.001-08:00

1. What is the difference between Based and Define?
2. What are the different storage classes in PL/1?
3. What are the file formats supported in PL/1?
4. Why do you need Translate?
5. How do you include an copybook?
6. What are the ways through which you pass value to an program from JCL?
7. Difference between main program and a sub program in PL/1?
8. Pseudo Variables in PL/1?
9. Difference between Do While and Do Until?
10. What are the different datatypes in PL/1?
11. How do you handle exception in PL/1?
12. Picture clause of TIME in PL/1?
13. Explain REENTRANT?
14. What are the different options in OPTIONS?
15. What is meant by REORDER option in PL/1?

!! Important Mainframe Interview Questions !!

2012-11-10T09:25:00.001-08:00

Some of the important Mainframe Interview Questions are listed below!!

1. Difference between STEPLIB and JOBLIB?

2. What is the use of MSGLEVEL in the job card?

3. In Which step timestamp is generated in the DB2-COBOL program compilation?

4. What is the picture clause of TIMESTAMP?

5. Difference between COMP and COMP-3?

6. What is the use of INSPECT statement?

7. How do you compare two files in COBOL?

8. What is Indexing?

9. What is the maximum time limit in TIME parameter?

10. How to extract the duplicate records in a file?

11. How to copy only 100 records from 200th record?

12. What are the mandatory DDNAMEs required using IDCAMS utility?

13. What is the specialty of IEFBR14 utility?

14. Which utility is used to load and unload records from DB2 tables?

15. What are the ways to pass data to a COBOL program?

16. What is the use of SPLIT command in SORT utility?

17. What is the use of SUM=NONE command in SORT?

18. Difference between INREC and OUTREC?

19. Expand COBOL?

20. Explain DB2-COBOL program compilation steps?

21. While using cursor, in which command the query is executed?

22. Use of cursors?

23. What is SQLCA?

24. Difference between STOPRUN and GOBACK.

25. How do you set max-cc from a COBOL program?

ISPF – List Last 25 COMMAND LINE Commands

2012-04-22T06:02:00.003-07:00

What are all the last 25 COMMAND LINE commands that you have issued from ISPFpanel ?

Solution:

Just use the command RETP. This will open the “ISPF Retrieve Panel” and will show you the commands you’ve issued.
This is an easy way to not only check what you’ve been doing but also to re-run a command without having to type it all over again.

ISPF - TIP #006

2012-04-22T05:59:00.000-07:00

We usually search for members in a PDS by the first string of the members.
Consider this situation:
I have a PDS and I want to search it for member only by middle string of the members.
e.g. there are some members like BESTJCL1,RESTJCL2,PESTCBL1, BESTCBL2,WESTCBL3,TESTASM1,BESTASM2...etc

I want to find members which have CBL in them.How can I search and find these members?

Answer:
Use ISPF 4.12 option.
Specify the dataset to be searched and the pattern of the string.
Specify the LANG type as COB
And select the browse option.

IDCAMS - Repro Command

2011-09-12T03:20:00.000-07:00

Copying A Data Set:

Note :
The CFILE utility, which was used to copy sequential and ISAM data sets, is not supported. Neither are ISAM data sets. All users with ISAM data sets should convert them to VSAM.

This article describes how to use IDCAMS/REPRO to copy a data set. It is intended as a replacement for CFILE and is not intended as complete documentation on VSAM data sets or the IDCAMS utility.

IDCAMS is an IBM utility that allows you to create and manipulate VSAM data sets. It has several commands. You can use the REPRO command of IDCAMS to copy VSAM and non-VSAM data sets, VSAM clusters, and alternate indexes.

You cannot use REPRO to copy an entire partitioned data set (PDS) because REPRO does not copy the information in the directories. You can, however, use REPRO to copy individual members.

The IBM IEBCOPY utility should be used to copy an entire PDS.

The REPRO Command
The general form of the REPRO command is as follows:

REPRO parameter parameter -
parameter -
parameter

Parameters may be separated by either commas or blanks. You can continue the REPRO statement by coding a hyphen (-) as the last character of a line. The command and parameters may be typed anywhere betweeen columns 2-72.

JCL for Using IDCAMS and REPRO
The below example shows the JCL for a basic job setup to access IDCAMS. The INFILE parameter names the DD statement for the data set that is to be copied. The OUTFILE parameter names the DD statement describing the output or target data set. You would replace "indd" and "outdd" with DD names of your own choosing.

JCL to Use IDCAMS and the REPRO Command
//COPY JOB ,'your name',CLASS=class,TIME=(mm,ss),LINES=lines
/*ROUTE PRINT node.location
// EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=A
//indd DD DSN= ... (describes the input data set)
//outdd DD DSN= ... (describes the output data set)
//SYSIN DD *
REPRO -
INFILE(indd) -
OUTFILE(outdd)
/*

Using REPRO to Copy a VSAM Data Set to A Sequential Data Set
//COPY JOB ,'your name',CLASS=class,TIME=(mm,ss),LINES=lines
/*ROUTE PRINT node.location
// EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=A
//VSAM DD DSN=UF.userid.VSAM.DATASET,DISP=OLD
//SEQ DD DSN=UF.userid.SEQ.BACKUP,UNIT=SYSDA,
// SPACE=(TRK,(10,10)),
// DISP=(NEW,CATLG),
// DCB=(LRECL=104,BLKSIZE=1004,RECFM=VB)
//SYSIN DD *
REPRO -
INFILE(VSAM) -
OUTFILE(SEQ)
/*

REPRO Examples
The below example shows how to use REPRO to copy a VSAM data set to a sequential data set. You could use this to make a sequential backup copy of your VSAM data set. In this example, assume that your VSAM data set has variable-length records. The maximum record size is 100 bytes and you have embedded keys. When you specify your LRECL and BLKSIZE for your output data set, make sure they are at least 4 bytes longer than the longest record in your VSAM data set.

Using REPRO to Backup a VSAM Data Set
//COPY JOB ,'your name',CLASS=class,TIME=(mm,ss),LINES=lines
/*ROUTE PRINT node.location
// EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=A
//OLD DD DSN=UF.userid.VSAM.DATASET,DISP=OLD
//NEW DD DSN=UF.userid.VSAM.BACKUP,DISP=OLD
//SYSIN DD *
REPRO -
INFILE(OLD) -
OUTFILE(NEW)
/*
This example assumes that you have already created the backup data set (using IDCAMS). The OLD DD name defines your original VSAM data set. The NEW DD name defines the output data set.

Optional Keywords for the REPRO Command
Suppose you want only to make a backup of part of your data set. You can use the SKIP(n) and COUNT(m) keywords on the REPRO command to delimit the records to be copied. The following form of the REPRO command would copy the input data set beginning with the 100th record and copy 500 records.

REPRO -
INFILE(VSAM) -
OUTFILE(SEQ) -
SKIP(99) -
COUNT(500)

ISPF - TIP #020

2011-06-30T03:32:00.000-07:00

Here is another tip on ISPF 3.4 option.
From the ISPF 3.4 option listing, I can directly Edit/Browse/view the member without listing all the members and then select the particular member.
Solution:
To do that, In the Line command issue, E / (member)use for Browse (B) and view (V) Command - Enter "/" to select action Message Volume

ISPF - TIP #019

2011-06-30T03:30:00.000-07:00

I have data which is of length 160. For some reasons, I want to wrap the data in each record to 80characters and have the next 80 characters in the next line. So basically what I am looking for is ,“Is there command similar to Wordwrap (as in Notepad or MS WORD) in mainframe?”
Solution:
Yes, with ISPF, one can wrap the data as required.To do that,
1.Open the dataset in ISPF EDIT mode.
2.In the first line, issue the line command: TF80 (as in this case I want to wrap to 80 chars perline)
3.All the subsequent lines will wrap to 80 chars per line.

ISPF - TIP #018

2011-06-30T03:27:00.000-07:00

Is there an easy way to search a member in Multiple PDS?

Solution:

Go to 3.4 (where all the datasets will be displayed) .

In the Command line type ==> M memname. For example: M sortpgm

This command will not work for the migrated PDS.

So ensure all the PDS are inDisk.Now the message "MEMBER(S): memname found" will apppear in the right side ofthe panel.

ISPF - TIP #017

2011-06-30T03:25:00.000-07:00

I have to compare one input file field with one output file field.
The input file field in is column1 to 10 and the output file field is in column 40 to 50.
How can I do it?
Solution:
1. Use the standard 3.13 ISPF option. In the same screen itself, in the command line issue, E
2. then type,
CMPCOLN 40:50
CMPCOLO 1:10
3. press PF3 and exit
4.In the New dataset , type in the output dataset
5. In the Old dataset , type in the input dataset

ISPF - TIP #016

2011-06-30T03:18:00.000-07:00

Here is a one simple one.....

I want to search a string like 'abc' (including quote).In my pgm there may be more abc strings.

But i don't want to retrieve all of them.i need the abc enclosed with quotes.

How to search is in 3.14 option?

Solution:

In the ISPF 3.14 , search with ‘’’abc’’’ string.(i.e. with 3 quotes at both sides of the string)

Abend s322!!

2011-06-21T09:53:00.000-07:00

Abend is a error that happens while we are running a job. There are so many abends which may come when we are running a job. This article discusses about the Abend code s322.

Abend s322 occurs when the job doesn't end within the given CPU time. CPU time is the time which we specify in the TIME attribute of a job card.

For example, if we give TIME =(5,0) i.e 5 minutes and 0 seconds. If the job doesn't end within 5 minutes, then Abend 322 will occur as a result of it.

Solution:

To avoid this Abend, always specify TIME=NOLIMIT in the job card. This will allow the job to take the maximum CPU time to complete a job.

ISPF - TIP #015

2011-06-10T04:51:00.000-07:00

Tired of typing the often-used datasets repeated?
Use NRETRIEV.
1 Enter KEYS in the command line,KEYS window will popup
2 Set any key to NRETRIEV and exit
3 Now when you are in 3.4 or whichever screen you have set the KEYS option, press theassigned PF keys.
4. Pressing them repeated will bring up one-by-one the last 30 accessed datasets from the reflist

ISPF - TIP #014

2011-06-10T04:04:00.000-07:00

When I issue CUT , I know that the CUT content are placed in a clipboard.
And when I issue PASTE, the clipboard content are pasted.
But is it possible for me to view/edit the clipboard ?
One can view the clipboard after any valid CUT command was issued.
To view the clipboard, issue : CUT DISPLAY.
Clipboard manager will pop up and gives us options to edit or browse thecontent.

ISPF - TIP #013

2011-06-01T04:51:00.000-07:00

How can You find the changes you have made lastly (without getting out of the screen) ?
Well, here is one simple command line command to achieve this
Solution: COMP * X

ISPF - TIP #012

2011-06-01T03:14:00.000-07:00

Here is a tip by which you can avoid ISPF 3.4 Option.
To Open a PS or PDS member, we usually use ISPF 3.4 to open in EDIT or BROWSE MODE.
Here is one way where one can open PS or PDS member in EDIT/VIEW/BROWSE mode from any command line.
Thus, we can avoid using 3.4 option.
Solution: EPDF ‘MYID.MYPS’ .
The Dataset will be opened in EDIT MODEIf you want to open in VIEW mode:
Solution : EPDF ‘MYID.MYPS’ VIEW
Similarly, for opening in BROWSE mode, type BROWSE at the end.

ISPF - TIP #011

2011-06-01T03:09:00.000-07:00

If you want to edit a member, which has TAB as a middle string in the PDS SAMPLE.MYPDS.
One shortcut way is to in the ISPF 3.4 listing of the PDS,issue S *TAB* E in the command line.
If we don’t use E at the end, it will open in browse mode.

ISPF - TIP #010

2011-05-25T02:10:00.000-07:00

What are all the last 25 COMMAND LINE commands that you have issued from ISPFpanel ?
How to know this?
Solution:
Type RETP on the Command line.

ISPF - TIP #009

2011-05-25T01:57:00.000-07:00

While Browsing Internet, we have some cool option called address Autocomplete…
we enter some letters in the address bar and the browser auto completes it with the closest guess.
Does MAINFRAME has the same feature??
Solution: Yes! It has “Autocomplete” feature!!!How to use it?
1.Go to ISPF 3.4 ,
2. Enter KEYS in the command line,KEYS window will popup
3. Set any key to AUTOTYPE, save and exit
4. Now type any Dataset partially and press the assigned PFkey!!
Note: It will not retrieve GDGs and VSAM files.

ISPF - TIP #008

2011-05-25T01:52:00.000-07:00

Alternate to SuperCE Option(3.13)
Use the macro COMPARE
Use this when you there is less difference between the two files.
1.Open a DSN in EDIT or VIEW Mode
2. On the Command line , issue COMP 'YOUR.SECOND.COMPARISON.DSN'
3. If you want only the changes to be listed, issue COMP'YOUR.SECOND.COMPARISON.DSN' EXC

ISPF - TIP #007

2011-05-25T01:50:00.000-07:00

How can I find the last 10 datasets that I have accessed ?

Solution:

1.GO TO ISPF 3.4 option.

2. On the top, there is a MENUBAR. Select REFLIST

3. Select Option 1 in it.

Using this option you can find out the last 30 datasets that you have accessed

ISPF - TIP #006

2011-05-25T01:45:00.000-07:00

We usual search for members in a PDS by the first string of the members.
Consider this situation ,I have a PDS and I want to search it for member only by middle string of the members.
for e.g. there are some members like BESTJCL1,RESTJCL2,PESTCBL1, BESTCBL2,WESTCBL3,TESTASM1,BESTASM2...etc.
I want to find members which have CBL in them.How can I search and find these members?

Solution:
1.Use ISPF 4.12 option.
2.Specify the dataset to be searched and the pattern of the string.
3.Specify the LANG type as COB And select the browse option.

ISPF - TIP #005

2011-05-24T03:47:00.000-07:00

While trying to open any member in a PDS, we sometimes come across "member in use" message.
In that situation, if you want to know who is using the membercurrently, press F1 twice.

ISPF - TIP #004

2011-05-24T03:43:00.000-07:00

Any command entered in the COMMAND LINE disappears after the successful execution of itsintended function.If you want to repeat the same command , you got to re-type it or use some PF key to retrieve thelast command entered.
But here is a cool method the make the command entered not to disappear and stay on the screen.Precede commands with '&'
For Example:
COMMAND ===> &C '100-para' '200-PARA' SCROLL ===> CSR****** ************************ TOP OF DATA **************
000001 IDENTIFICATION DIVISION.
000002 PROGRAM-ID. PROGRAM1.
000003 DATE-WRITTEN. MAY 2011.
After the execution of the command, the below command stays on the screen.
This way you can entering the same command or modifying the command a little and using itmultiple times.

ISPF - TIP #003

2011-05-24T03:42:00.000-07:00

Suppose you are in a ISPF Screen and want to know in which TSO Region ( Development,Production, or other TSO regions) you are now .

Solution:Issue on the command line : SAREAISPF STATISTICS Pop-up window will show you the region( and other info too)