Question on COMP in COBOL program

1. Sign storage in COMP-3 field,

The sign indicator is always stored at the last bit.
If your number is +100, it stores hex 0C in the last byte.
If your number is -101, it stores hex 1D in the last byte.

2. Sign stored in COMP field.

The Sign is stored in the Most significant bit.
Bit is ON if -ve.
Bit is OFF if +ve.

3. difference between COMP & COMP-3.

COMP is a binary storage format.
COMP-3 is a Packed decimal format.

4. difference between COMP-1 & COMP-2.

COMP-1 - Represented as Single floating point. Uses 4 bytes.
COMP-2 - Represented as Double floating point. Uses 8 bytes.

5. S9(7) COMP-3 field occupy?

According to the formula  INT((n + 1)/2) 
n=7
INT((7+1)/2)) = 4.
This will take 4 bytes.

6. S9(8) COMP field occupy?

4 bytes. As the number of bytes are divided by 2.

7. S9(7) SIGN TRAILING SEPARATE field occupy?

8 bytes as the sign will remain as 1 byte due to trailing separate.

Simple android program using onTouchEvent

This is the MainActivity which calls the TouchToView class,

package com.example.paintouch;

import android.app.Activity;
import android.os.Bundle;


public class MainActivity extends Activity {

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
     //   setContentView(R.layout.activity_main);
        setContentView(new TouchToView(this));
    }

}

Here we have used onTouchEvent which will capture the motion of your finger when touching the screen and also we have defined the Paint and Path with its style, colour and width to get displayed.
The X and Y axis will be mapped with using the paint and path.

package com.example.paintouch;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Join;
import android.graphics.Paint.Style;
import android.graphics.Path;
import android.view.MotionEvent;
import android.view.View;

public class TouchToView extends View{
private Paint alphanum = new Paint();
private Path trace = new Path();

public TouchToView(Context context) {
super(context);
// TODO Auto-generated constructor stub
alphanum.setAntiAlias(true);
alphanum.setStrokeWidth(6f);
alphanum.setColor(Color.RED);
alphanum.setStyle(Style.STROKE);
alphanum.setStrokeJoin(Join.ROUND);
}

protected void onDraw(Canvas canvas) {
canvas.drawPath(trace, alphanum);
}

@SuppressLint("ClickableViewAccessibility")
public boolean onTouchEvent(MotionEvent event) {
Float eventX = event.getX();
Float eventY = event.getY();

switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
trace.moveTo(eventX, eventY);
break;
case MotionEvent.ACTION_MOVE:
trace.lineTo(eventX, eventY);
break;
case MotionEvent.ACTION_UP:
// trace.lineTo(eventX, eventY); do nothing
break;
case MotionEvent.ACTION_OUTSIDE:
// trace.lineTo(eventX, eventY); do nothing
break;
default:
return false;
}
invalidate();
return true;

}

}

How to find special character in String using COBOL program

How to check special character in a string and replace with spaces using COBOL program.


01  TEMP-VAR                            PIC X(10) VALUE " INS#PECT ".
01  TEMP-VAR-LEN                   PIC 9(02) VALUE ZERO.
01  TEMP-VAR-COUNT             PIC 9(02) VALUE ZERO.
01  TEMP-CHAR-COUNT          PIC 9(02) VALUE ZERO.
01  TEMP-CHAR                         PIC X(10) VALUE SPACES.
01  TEMP-CHK-VAR                  PIC X(10) VALUE SPACES.


MOVE LENGTH OF TEMP-VAR TO TEMP-VAR-LEN.      

MOVE 0                   TO TEMP-VAR-COUNT.      
      
PERFORM VARYING TEMP-CHAR-COUNT FROM 1 BY 1                
            UNTIL TEMP-CHAR-COUNT > TEMP-VAR-LEN        

  MOVE  TEMP-VAR(TEMP-CHAR-COUNT:1) TO TEMP-CHAR  

  ADD 1                  TO TEMP-VAR-COUNT                

  EVALUATE TEMP-CHAR                                  
     WHEN ‘#’                                  
        MOVE SPACES TO TEMP-CHG-VAR(WS-VAR-COUNT:1)
     WHEN OTHER
        MOVE TEMP-CHAR TO TEMP-CHK-VAR(WS-VAR-COUNT:1)
  END-EVALUATE

END-PERFORM.


Here the logic is:
To get the length of the string and perform until the complete string has been checked, each word is checked using the EVALUATE and if the special character is found it will be replaced with spaces or the same character will be moved into the variable using reference modification. 

How to remove spaces in a String

How to remove front and back spaces in a variable and write it in middle of two variable,

01  VAR-SPACE            PIC X(10) VALUE '   DATA   '.
01  LEAD-SPACE         PIC 9(04)  COMP.
01  TRAIL-SPACE        PIC 9(04)  COMP.
01  LENG-SPACE         PIC 9(04)  COMP.
01  FIRST-VAR             PIC X(07) VALUE 'VALID -'.
01  TRAIL-VAR            PIC X(10) VALUE '- REQUIRED'.
01  FINAL-VAR            PIC X(21) VALUE SPACES.


INSPECT              VAR-SPACE
      TALLYING     LEAD-SPACE          
      FOR LEADING SPACES    
                 
INSPECT    FUNCTION REVERSE(VAR-SPACE)
     TALLYING    TRAIL-SPACE          
     FOR LEADING SPACES      
                
COMPUTE  SPACE-LENG =                        
                  LENGTH OF  VAR-SPACE - LEAD-SPACE - TRAIL-SPACE     
          
ADD    1                    TO   LEAD-SPACE    

STRING FIRST-VAR DELIMITED BY SIZE  
       VAR-SPACE (LEAD-SPACE:SPACE-LENG)
                                DELIMITED BY SIZE
       TRAIL-VAR   DELIMITED BY SIZE  
       INTO FINAL-VAR.    

DISPLAY "The result will be: " FINAL-VAR.


The result will be: VALID -DATA- REQUIRED.

Here the spaces which are present in front and back of 'VAR-SPACE' variable has to be removed.
So we have used INSPECT function to check for number of spaces in front and back using TALLYING function.
Then using reference modification only the DATA is moved after removing the leading and trailing spaces.

How to check whether a file is empty using JCL?

We can check whether a file is empty using the below methods,

USING IDCAMS

//STEP01 EXEC PGM=IDCAMS                          
//SYSPRINT DD  SYSOUT=*                            
//SYSOUT   DD  SYSOUT=*                            
//DDIN     DD  DSN=&TEST.DATA.FILE,DISP=SHR
//SYSIN    DD*
    PRINT INFILE(DDIN) COUNT(1) CHAR
/*    


IF RETURN CODE IS EQUAL TO 4 THE FILE IS EMPTY


USING SELCOPY

//STEP01 EXEC PGM=SELCOPY                          
//SYSPRINT DD  SYSOUT=*                            
//SYSOUT   DD  SYSOUT=*                            
//DDIN     DD  DSN=&TEST.DATA.FILE,DISP=SHR
//DDOUT    DD  DUMMY
//SYSIN    DD*
     READ DDIN
     WRITE DDOUT
/*    

IF THE RETURN CODE IS = 16 THEN THE FILE IS EMPY

USING ICETOOL

//STEP01 EXEC PGM=ICETOOL                          
//TOOLMSG  DD  SYSOUT=*                            
//DFSMSG   DD  SYSOUT=*                            
//DDIN     DD  DSN=&TEST.DATA.FILE,DISP=SHR
//TOOLIN   DD  DATA
     COUNT FROM(DDIN) EMPTY
/*    

IF THE RETURN CODE IS = 0 THEN THE FILE IS NOT EMPY ELSE EMPTY


USING IKJEFT01

//STEP01  EXEC PGM=IKJEFT01,DYNAMNBR=25

COUNTS THE NUMBER OF RECORDS IN THE FEED FILE

IF RETURN CODE IS LESS THEN 4 THE FILE IS EMPTY ELSE THE FILE HAS DATA.

COND in JCL

COND=(0,EQ) OR COND=(0,EQ,STEP01) OR COND=ONLY OR COND=EVEN

0             = RETURN CODE 
EQ         = LOGICAL OPERATOR (WE CAN GIVE CONDITIONS LIKE (GT - GREATER THEN,                  LT - LESSER THEN, GE - GREATER THEN OR EQUAL TO, LE - LESSER THEN OR                  EQUAL TO, EQ - EQUAL TO, NE - NOT EQUAL TO)
STEP01 = STEP NAME WHICH RETURN CODE HAS TO BE CONSIDERED.


EQUAL TO & NOT EQUAL TO

Eg:
//STEP01  EXCE  PGM=IKJEFT01
//
//STEP02  EXEC  PGM=IDCAMS,     
//              COND=(0,EQ,STEP01)


HERE THE STEP02 WILL BE BY PASSED IF THE STEP01 ENDS WITH RETURN CODE 0
IF THE CONDITION IS TRUE THEN THE STEP WILL GET BY PASSED IF THE CONDITION IS FALSE THEN THE STEP WILL GET EXECUTED.

Eg:
//STEP01  EXEC  PGM=IKJEFT01
//
//STEP02  EXEC  PGM=IDCAMS,     
//              COND=(0,NE,STEP01) 

HERE THE STEP02 WILL GET EXECUTED IF THE STEP01 ENDS WITH RETURN CODE > 0

LESS THEN & GREATER THEN

Eg:
//STEP01  EXEC  PGM=IKJEFT01
//
//STEP02  EXEC  PGM=IDCAMS,     
//              COND=(04,LT,STEP01)


HERE THE STEP02 WILL BE BY PASSED IF THE STEP01 ENDS WITH RETURN CODE 0
IF THE CONDITION IS TRUE THEN THE STEP WILL GET BY PASSED IF THE CONDITION IS FALSE THEN THE STEP WILL GET EXECUTED.

Eg:
//STEP01  EXEC  PGM=IKJEFT01
//
//STEP02  EXEC  PGM=IDCAMS,     
//              COND=(0,GT,STEP01) 

HERE THE STEP02 WILL GET EXECUTED IF THE STEP01 ENDS WITH RETURN CODE < 0

EVEN & ONLY
Eg:
//STEP01  EXEC  PGM=IKJEFT01
//
//STEP02  EXEC  PGM=IDCAMS,     
//              COND=EVEN 

HERE THE STEP02 WILL GET EXECUTED EVEN IF THE PREVIOUS STEP ABENDS OR SUCCESSFUL

Eg:
//STEP01  EXEC  PGM=IKJEFT01
//
//STEP02  EXEC  PGM=IDCAMS,    
//              COND=ONLY 

HERE THE STEP02 WILL GET EXECUTED ONLY IF THE PREVIOUS STEPS ABENDS

Overriding only one dataset in 3 concatenated datasets

Mention the override step with specific DD names with spaces for which we are not going to specify with any overrides from JCL.

For eg:

//STEP1.PRC   DD DSN=
//DDF1              DD DSN=MLOGI.DATA.FILE2,DISP=SHR
//DDF2              DD DSN=

Do not specify DD names with DUMMY as the datasets will be considered as DUMMY.

For eg:

//STEP1.PRC   DD DUMMY
//DDF1              DD DSN=MLOGI.DATA.FILE2,DISP=SHR
//DDF2              DD DUMMY