MainframeMaster

COBOL Tutorial

COBOL POSITION

The POSITION concept in COBOL represents comprehensive data positioning and sophisticated location tracking capabilities within enterprise programming environments, providing advanced string positioning mechanisms for precise data placement, enhanced character location features for text processing operations, and intelligent position management capabilities that enable accurate data positioning, optimal string parsing workflows, and systematic location tracking while maintaining position accuracy, ensuring efficient text processing, and enabling flexible positioning architectures across business applications requiring exact data placement, character-level processing, and reliable position management throughout sophisticated text parsing and data extraction scenarios.

POSITION in String Operations

String Positioning and Location Tracking
cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
*> POSITION usage in string operations
WORKING-STORAGE SECTION.
01 WS-STRING-OPERATIONS.
   05 WS-SOURCE-STRING      PIC X(100) VALUE 
      "JOHN,DOE,MANAGER,75000,CHICAGO,IL,60601".
   05 WS-PARSED-DATA.
      10 WS-FIRST-NAME      PIC X(20).
      10 WS-LAST-NAME       PIC X(20).
      10 WS-TITLE           PIC X(20).
      10 WS-SALARY          PIC X(10).
      10 WS-CITY            PIC X(20).
      10 WS-STATE           PIC X(5).
      10 WS-ZIP-CODE        PIC X(10).
   05 WS-POSITION-DATA.
      10 WS-NAME-POSITION   PIC 9(3).
      10 WS-TITLE-POSITION  PIC 9(3).
      10 WS-SALARY-POSITION PIC 9(3).
      10 WS-CITY-POSITION   PIC 9(3).
      10 WS-STATE-POSITION  PIC 9(3).
      10 WS-ZIP-POSITION    PIC 9(3).
 
01 WS-STRING-POINTER        PIC 9(3) VALUE 1.
01 WS-CURRENT-POSITION      PIC 9(3).
 
PROCEDURE DIVISION.
DEMONSTRATE-STRING-POSITIONING.
    DISPLAY "=== STRING POSITIONING OPERATIONS ==="
    
    *> Parse string with position tracking
    UNSTRING WS-SOURCE-STRING
        DELIMITED BY ","
        INTO WS-FIRST-NAME  DELIMITER IN WS-DELIMITER-1
                           POSITION IN WS-NAME-POSITION
             WS-LAST-NAME   DELIMITER IN WS-DELIMITER-2
                           POSITION IN WS-TITLE-POSITION
             WS-TITLE       DELIMITER IN WS-DELIMITER-3
                           POSITION IN WS-SALARY-POSITION
             WS-SALARY      DELIMITER IN WS-DELIMITER-4
                           POSITION IN WS-CITY-POSITION
             WS-CITY        DELIMITER IN WS-DELIMITER-5
                           POSITION IN WS-STATE-POSITION
             WS-STATE       DELIMITER IN WS-DELIMITER-6
                           POSITION IN WS-ZIP-POSITION
             WS-ZIP-CODE
        WITH POINTER WS-STRING-POINTER
    END-UNSTRING
    
    *> Display parsed data with positions
    DISPLAY "Parsed Data with Positions:"
    DISPLAY "First Name: " WS-FIRST-NAME " (Position: " WS-NAME-POSITION ")"
    DISPLAY "Last Name: " WS-LAST-NAME " (Position: " WS-TITLE-POSITION ")"
    DISPLAY "Title: " WS-TITLE " (Position: " WS-SALARY-POSITION ")"
    DISPLAY "Salary: " WS-SALARY " (Position: " WS-CITY-POSITION ")"
    DISPLAY "City: " WS-CITY " (Position: " WS-STATE-POSITION ")"
    DISPLAY "State: " WS-STATE " (Position: " WS-ZIP-POSITION ")"
    DISPLAY "ZIP: " WS-ZIP-CODE
 
*> Advanced position tracking
TRACK-FIELD-POSITIONS.
    01 WS-RECORD-LAYOUT.
       05 WS-FIELD-POSITIONS OCCURS 10 TIMES.
          10 WS-FIELD-NAME   PIC X(15).
          10 WS-START-POS    PIC 9(3).
          10 WS-END-POS      PIC 9(3).
          10 WS-FIELD-LENGTH PIC 9(3).
    
    MOVE "FIRST_NAME" TO WS-FIELD-NAME(1)
    MOVE WS-NAME-POSITION TO WS-START-POS(1)
    COMPUTE WS-END-POS(1) = WS-TITLE-POSITION - 1
    COMPUTE WS-FIELD-LENGTH(1) = WS-END-POS(1) - WS-START-POS(1) + 1
    
    MOVE "LAST_NAME" TO WS-FIELD-NAME(2)
    MOVE WS-TITLE-POSITION TO WS-START-POS(2)
    COMPUTE WS-END-POS(2) = WS-SALARY-POSITION - 1
    COMPUTE WS-FIELD-LENGTH(2) = WS-END-POS(2) - WS-START-POS(2) + 1
    
    DISPLAY "Field Layout Analysis:"
    PERFORM VARYING FIELD-INDEX FROM 1 BY 1 UNTIL FIELD-INDEX > 2
        DISPLAY "Field: " WS-FIELD-NAME(FIELD-INDEX)
        DISPLAY "  Start: " WS-START-POS(FIELD-INDEX)
        DISPLAY "  End: " WS-END-POS(FIELD-INDEX)
        DISPLAY "  Length: " WS-FIELD-LENGTH(FIELD-INDEX)
    END-PERFORM
String Processing
Position Tracking
Data Location

Advanced Position Operations

Complex Positioning and Data Extraction
cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
*> Advanced position operations for data processing
01 WS-XML-PROCESSING.
   05 WS-XML-STRING         PIC X(500) VALUE
      "12345John Doe1500.75".
   05 WS-TAG-POSITIONS OCCURS 10 TIMES.
      10 WS-TAG-NAME        PIC X(20).
      10 WS-START-TAG-POS   PIC 9(3).
      10 WS-END-TAG-POS     PIC 9(3).
      10 WS-CONTENT-START   PIC 9(3).
      10 WS-CONTENT-END     PIC 9(3).
   05 WS-EXTRACTED-VALUES.
      10 WS-CUSTOMER-ID     PIC X(10).
      10 WS-CUSTOMER-NAME   PIC X(30).
      10 WS-CUSTOMER-BALANCE PIC X(15).
 
01 WS-CSV-PROCESSING.
   05 WS-CSV-RECORD        PIC X(200) VALUE
      '"Product A","Electronics","$299.99","In Stock","Warehouse A"'.
   05 WS-QUOTE-POSITIONS OCCURS 20 TIMES.
      10 WS-QUOTE-START    PIC 9(3).
      10 WS-QUOTE-END      PIC 9(3).
   05 WS-CSV-FIELDS.
      10 WS-PRODUCT-NAME   PIC X(30).
      10 WS-CATEGORY       PIC X(20).
      10 WS-PRICE          PIC X(15).
      10 WS-STATUS         PIC X(15).
      10 WS-LOCATION       PIC X(20).
 
PROCEDURE DIVISION.
PROCESS-XML-POSITIONS.
    DISPLAY "=== XML POSITION PROCESSING ==="
    
    *> Find and extract XML tag positions
    MOVE 1 TO WS-SEARCH-POSITION
    MOVE 1 TO WS-TAG-COUNT
    
    *> Find customer ID
    PERFORM FIND-XML-TAG-POSITION
        USING "" "" "ID" 1
    
    *> Find customer name  
    PERFORM FIND-XML-TAG-POSITION
        USING "" "" "NAME" 2
    
    *> Find customer balance
    PERFORM FIND-XML-TAG-POSITION
        USING "" "" "BALANCE" 3
    
    *> Extract values based on positions
    PERFORM EXTRACT-XML-VALUES
    
    DISPLAY "Extracted XML Data:"
    DISPLAY "  ID: " WS-CUSTOMER-ID
    DISPLAY "  Name: " WS-CUSTOMER-NAME
    DISPLAY "  Balance: " WS-CUSTOMER-BALANCE
 
FIND-XML-TAG-POSITION.
    USING START-TAG END-TAG TAG-NAME TAG-INDEX.
    
    *> Find start tag position
    INSPECT WS-XML-STRING(WS-SEARCH-POSITION:)
        TALLYING WS-CHAR-COUNT FOR CHARACTERS BEFORE INITIAL START-TAG
    COMPUTE WS-START-TAG-POS(TAG-INDEX) = WS-SEARCH-POSITION + WS-CHAR-COUNT
    
    *> Calculate content start position
    COMPUTE WS-CONTENT-START(TAG-INDEX) = 
        WS-START-TAG-POS(TAG-INDEX) + FUNCTION LENGTH(START-TAG)
    
    *> Find end tag position
    INSPECT WS-XML-STRING(WS-CONTENT-START(TAG-INDEX):)
        TALLYING WS-CHAR-COUNT FOR CHARACTERS BEFORE INITIAL END-TAG
    COMPUTE WS-CONTENT-END(TAG-INDEX) = 
        WS-CONTENT-START(TAG-INDEX) + WS-CHAR-COUNT - 1
    
    MOVE TAG-NAME TO WS-TAG-NAME(TAG-INDEX)
    
    DISPLAY "Tag: " TAG-NAME 
    DISPLAY "  Content Position: " WS-CONTENT-START(TAG-INDEX) 
            " to " WS-CONTENT-END(TAG-INDEX)
 
EXTRACT-XML-VALUES.
    *> Extract customer ID
    COMPUTE WS-EXTRACT-LENGTH = 
        WS-CONTENT-END(1) - WS-CONTENT-START(1) + 1
    MOVE WS-XML-STRING(WS-CONTENT-START(1):WS-EXTRACT-LENGTH)
        TO WS-CUSTOMER-ID
    
    *> Extract customer name
    COMPUTE WS-EXTRACT-LENGTH = 
        WS-CONTENT-END(2) - WS-CONTENT-START(2) + 1
    MOVE WS-XML-STRING(WS-CONTENT-START(2):WS-EXTRACT-LENGTH)
        TO WS-CUSTOMER-NAME
    
    *> Extract customer balance
    COMPUTE WS-EXTRACT-LENGTH = 
        WS-CONTENT-END(3) - WS-CONTENT-START(3) + 1
    MOVE WS-XML-STRING(WS-CONTENT-START(3):WS-EXTRACT-LENGTH)
        TO WS-CUSTOMER-BALANCE
 
PROCESS-CSV-POSITIONS.
    DISPLAY " "
    DISPLAY "=== CSV POSITION PROCESSING ==="
    
    *> Find quoted field positions
    MOVE 1 TO WS-SEARCH-POSITION
    MOVE 0 TO WS-QUOTE-COUNT
    
    PERFORM VARYING CHAR-INDEX FROM 1 BY 1 
        UNTIL CHAR-INDEX > FUNCTION LENGTH(WS-CSV-RECORD)
        
        IF WS-CSV-RECORD(CHAR-INDEX:1) = '"'
            ADD 1 TO WS-QUOTE-COUNT
            
            IF WS-QUOTE-COUNT IS ODD
                MOVE CHAR-INDEX TO WS-QUOTE-START((WS-QUOTE-COUNT + 1) / 2)
            ELSE
                MOVE CHAR-INDEX TO WS-QUOTE-END(WS-QUOTE-COUNT / 2)
            END-IF
        END-IF
    END-PERFORM
    
    *> Extract CSV fields based on quote positions
    PERFORM EXTRACT-CSV-FIELDS
    
    DISPLAY "Extracted CSV Data:"
    DISPLAY "  Product: " WS-PRODUCT-NAME
    DISPLAY "  Category: " WS-CATEGORY
    DISPLAY "  Price: " WS-PRICE
    DISPLAY "  Status: " WS-STATUS
    DISPLAY "  Location: " WS-LOCATION
 
EXTRACT-CSV-FIELDS.
    *> Extract each quoted field
    PERFORM VARYING FIELD-INDEX FROM 1 BY 1 UNTIL FIELD-INDEX > 5
        COMPUTE WS-FIELD-START = WS-QUOTE-START(FIELD-INDEX) + 1
        COMPUTE WS-FIELD-LENGTH = 
            WS-QUOTE-END(FIELD-INDEX) - WS-QUOTE-START(FIELD-INDEX) - 1
        
        EVALUATE FIELD-INDEX
            WHEN 1
                MOVE WS-CSV-RECORD(WS-FIELD-START:WS-FIELD-LENGTH) 
                    TO WS-PRODUCT-NAME
            WHEN 2
                MOVE WS-CSV-RECORD(WS-FIELD-START:WS-FIELD-LENGTH) 
                    TO WS-CATEGORY
            WHEN 3
                MOVE WS-CSV-RECORD(WS-FIELD-START:WS-FIELD-LENGTH) 
                    TO WS-PRICE
            WHEN 4
                MOVE WS-CSV-RECORD(WS-FIELD-START:WS-FIELD-LENGTH) 
                    TO WS-STATUS
            WHEN 5
                MOVE WS-CSV-RECORD(WS-FIELD-START:WS-FIELD-LENGTH) 
                    TO WS-LOCATION
        END-EVALUATE
    END-PERFORM

Complete POSITION System

cobol
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
IDENTIFICATION DIVISION.
PROGRAM-ID. POSITION-DEMO.
 
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WS-POSITION-CONTROL.
   05 WS-PROCESSING-COUNT   PIC 9(4) VALUE 0.
   05 WS-POSITION-ERRORS    PIC 9(3) VALUE 0.
   05 WS-EXTRACTION-COUNT   PIC 9(4) VALUE 0.
 
01 WS-LOG-PROCESSING.
   05 WS-LOG-RECORD        PIC X(300) VALUE
      "2023-12-25 14:30:45 [INFO] User john.doe logged in from IP 192.168.1.100".
   05 WS-LOG-COMPONENTS.
      10 WS-LOG-DATE       PIC X(10).
      10 WS-LOG-TIME       PIC X(8).
      10 WS-LOG-LEVEL      PIC X(10).
      10 WS-LOG-MESSAGE    PIC X(100).
      10 WS-LOG-IP         PIC X(15).
 
PROCEDURE DIVISION.
MAIN-POSITION-DEMO.
    DISPLAY "=== COMPREHENSIVE POSITION DEMO ==="
    
    PERFORM PARSE-LOG-ENTRIES
    PERFORM VALIDATE-POSITION-DATA
    PERFORM DISPLAY-EXTRACTION-RESULTS
    
    DISPLAY "=== POSITION DEMO COMPLETE ==="
    STOP RUN.
 
PARSE-LOG-ENTRIES.
    DISPLAY "Parsing log entries with position tracking..."
    
    *> Parse log components using position-aware extraction
    UNSTRING WS-LOG-RECORD
        DELIMITED BY " "
        INTO WS-LOG-DATE
             WS-LOG-TIME
             WS-LOG-LEVEL DELIMITER IN WS-DELIMITER
             WS-LOG-MESSAGE
        COUNT IN WS-FIELD-COUNT
    END-UNSTRING
    
    ADD 1 TO WS-PROCESSING-COUNT
    ADD 1 TO WS-EXTRACTION-COUNT
    
    DISPLAY "✅ Log entry parsed successfully"
 
DISPLAY-EXTRACTION-RESULTS.
    DISPLAY "📊 Position Processing Results:"
    DISPLAY "  Records processed: " WS-PROCESSING-COUNT
    DISPLAY "  Extractions: " WS-EXTRACTION-COUNT
    DISPLAY "  Errors: " WS-POSITION-ERRORS
    DISPLAY " "
    DISPLAY "Extracted log components:"
    DISPLAY "  Date: " WS-LOG-DATE
    DISPLAY "  Time: " WS-LOG-TIME
    DISPLAY "  Level: " WS-LOG-LEVEL
    DISPLAY "  Message: " WS-LOG-MESSAGE

POSITION Features and Capabilities

String Processing
  • • Character position tracking
  • • Field boundary detection
  • • String parsing coordination
  • • Data extraction positioning
Data Location
  • • Tag position identification
  • • Field start/end tracking
  • • Content boundary detection
  • • Layout analysis support

Best Practices

Related Concepts

String Operations

String manipulation and processing

Text Processing

Character and text handling

Data Parsing

Data extraction and analysis