Compaq COBOL
Reference Manual
Previous Contents Index

Technical Notes

Additional References

See the OpenVMS Calling Standard for more information.

Examples

  1. Passing arguments by reference: 


    CALL "DATERTN" USING ITEMA ITEMB ITEMC.

  2. On OpenVMS, mixing argument-passing mechanisms: Reference arguments are ITEMA, ITEMD, and "PAYROLL". Descriptor arguments are ITEMB, ITEMC, ITEMD, "TOTALS", and ITEMF. The value arguments are ITEME and "995.99". ITEMD is passed twice---by reference and by descriptor. The content arguments are ITEMG and "SUMMARY FLAG". 


    CALL "NEWPROG" USING ITEMA 
  BY DESCRIPTOR ITEMB ITEMC "TOTALS" 
  BY REFERENCE ITEMD "PAYROLL" 
  BY VALUE ITEME 995.99 
  BY DESCRIPTOR ITEMD ITEMF 
  BY CONTENT ITEMG "SUMMARY FLAG".                        <>

  3. Mixing argument-passing mechanisms: Reference arguments are ITEMA, ITEMD, and "PAYROLL". The value arguments are ITEME and "995.99". The content arguments are ITEMG and "SUMMARY FLAG". 


    CALL "NEWPROG" USING ITEMA 
  BY REFERENCE ITEMD "PAYROLL" 
  BY VALUE ITEME 995.99 
  BY CONTENT ITEMG "SUMMARY FLAG".

  4. Calling a program whose name is selected at run time: 


    MOVE "PROG009" TO PROG-TO-CALL. 
. 
. 
. 
CALL PROG-TO-CALL USING ITEMA.

  5. Receiving a function result: 


    CALL "PROG010" USING ITEMA ITEMB "XYZ" 
  GIVING ITEMC.

6.8.5 CANCEL

Function

The CANCEL statement returns the named program to its initial state.

prog-name

is a nonnumeric literal or the identifier of an alphanumeric data item. It contains the program-name of the program to be canceled.

Syntax Rules

  1. prog-name must be from 1 to 31 characters long. It can contain the characters A to Z, a to z, 0 to 9, dollar sign ($), hyphen (-), and underline (_).
  2. prog-name must be the name of a Compaq COBOL program.

General Rules

  1. Two or more programs in the run unit can have the same prog-name. The scope of names conventions for prog-names resolve the CANCEL statement references to duplicate prog-names. (See the section on Conventions for Resolving Program-Name References.)
  2. Using the scope of names conventions (See Section 6.2.6 ), if prog-name is called again after the CANCEL statement successfully executes, prog-name, and all programs contained within it, are in their initial state.
  3. prog-name must be callable by the program that contains the CANCEL statement.
  4. The program named by prog-name must not refer directly or indirectly to any program that: (a) has been called, and (b) has not yet executed an EXIT PROGRAM statement.
  5. When the CANCEL statement executes, the contents of prog-name are interpreted as follows:
  6. A called program can be canceled in three ways:
  7. When canceling a program these items do not change: (a) the contents of its data items in external data records, and (b) the status and positioning of a file associated with any external file connector.
  8. During the execution of a CANCEL statement, an implicit CLOSE statement without any optional phrases executes for each file in the open mode that is associated with an internal file connector in prog-name.

Additional References

Examples

  1. CANCEL "PROG10".
  2. CANCEL THE-PROG.
  3. CANCEL SUB-PROG-A "PROG12" SUB-PROG-B.

6.8.6 CLOSE

Function

The CLOSE statement ends processing of reels (or units) and files. It can also perform rewind, lock, and removal operations.

file-name

is the name of a file described in the Data Division. It cannot be a sort or merge file.

Syntax Rules

  1. The REEL or UNIT phrase can be used only for sequential and line sequential files.
  2. The words REEL and UNIT are equivalent.

General Rules

  1. A CLOSE statement can execute only for an open file.
  2. Executing a CLOSE statement updates the value of the FILE STATUS data item associated with the file.
  3. The TERMINATE statement must be executed before a CLOSE statement can reference a report file.
  4. If an optional file is not present, standard end-of-file processing does not occur.
  5. The WITH NO REWIND and FOR REMOVAL phrases have no effect at execution time if they do not apply to the file's storage medium, except as specified in General Rule 2.
  6. When the CLOSE statement applies to an output or extend file described with the LINAGE clause, end-of-page processing occurs before the file is closed.
  7. After successful CLOSE statement execution (without the REEL or UNIT phrase), the file's record area is no longer available. After unsuccessful execution, record area availability is undefined.
  8. After successful CLOSE statement execution (without the REEL or UNIT phrase), the file is no longer: (a) in the open mode or (b) associated with the file connector.
  9. If the CLOSE statement has more than one file-name, the statement executes as if there were a separate CLOSE statement for each file-name.
  10. In the file-sharing environment, CLOSE statement execution unlocks all locks for file-name.
  11. If both the REEL/UNIT and WITH NO REWIND phrases are specified in the same CLOSE statement, the WITH NO REWIND phrase is ignored.
  12. To show the effects of CLOSE statements, all files are categorized as follows:
  13. For files specified with a MULTIPLE FILE TAPE clause the NO REWIND phrase, if any, is ignored.
  14. Table 6-12 summarizes CLOSE statement results. Symbol definitions follow the table.
    Where definitions differ for input, output, and input-output files, separate definitions appear. Otherwise, a definition applies to files in all open modes.

    Table 6-12 Effects of CLOSE Statement Formats on Files by Category
      File Category
    CLOSE
    Statement
    Format     		Nonreel Sequential
    Single-Reel     		Sequential
    Multireel     		Nonsequential
    CLOSE C C,G C,G,A C
    CLOSE WITH LOCK C,E C,G,E C,G,E,A C,E
    CLOSE WITH NO REWIND C,H C,B C,B,A X
    CLOSE REEL F F,G F,G X
    CLOSE REEL FOR REMOVAL F F,D,G F,D,G X

    1. Previous reels unaffected
      For input and input-output files: All reels in the file before the current reel are processed according to the standard reel swap procedure. However, reels controlled by an earlier CLOSE REEL/UNIT statement are not affected. If other reels in the file follow the current reel, they are not processed.
      For output files: All reels in the file before the current reel are processed according to the standard reel swap procedure. However, reels controlled by an earlier CLOSE REEL/UNIT statement are not affected.
    1. No rewind of current reel
      The position of the current reel remains the same.

    1. Close file
      The file is closed.
    1. Reel/unit removal
      The current reel rewinds and is logically removed from the run unit However, the run unit can access the reel again in its proper order of reels in the file. To do this, the executable image must subsequently execute the following:
      • A CLOSE statement without the REEL/UNIT phrase for the file
      • An OPEN statement for the file
    1. File lock
      The executable image cannot open the file again in its current execution.
    1. Close reel/unit
      For input and input-output files, if the current reel is the last or only reel for the file:
      • A reel swap does not occur.
      • The Current Volume Pointer remains the same.
      • The File Position Indicator denotes that there is no next logical record.

      If another reel follows the current reel for the file:
      • A reel swap occurs.
      • The Current Volume Pointer points to the next reel for the file.
      • The File Position Indicator points to the next record in the file. If there are no records for the current volume, another reel swap occurs.

      For output files (reel/unit media), a reel swap occurs. The Current Volume Pointer points to the new reel.
      Executing the next WRITE statement for the file transfers a logical record to the new reel of the file.
      For output files (nonreel/unit media), execution of this statement is considered successful. The file remains in the open mode and no action takes place, except as specified in General Rule 2.
    1. Rewind
      The current reel (or device) is positioned to its physical beginning.
    1. Optional phrases ignored
      The CLOSE statement is executed as if none of the optional phrases are present.
    1. Invalid
      This is an invalid combination of CLOSE option and file category. It results in FILE STATUS data item value 30.

Technical Note

CLOSE statement execution can result in these FILE STATUS data item values:
File Status Meaning
00 Successful
07 CLOSE statement with NO REWIND, REEL/UNIT, or FOR REMOVAL phrase referenced a file on a nonreel/unit medium
30 Any other CLOSE error
42 File never opened, already closed, or not currently open

Additional Reference

See Section 6.6.8, I-O Status for more information.

6.8.7 COMPUTE

Function

The COMPUTE statement evaluates an arithmetic expression and stores the result in one or more data items.

rsult

is the identifier of an elementary numeric item or elementary numeric edited item. It is the resultant identifier.

arithmetic-expression

is an expression as described in Section 6.4, Arithmetic Expressions.

stment

is an imperative statement executed when a size error condition has occurred.

stment2

is an imperative statement executed when no size error condition has occurred.

General Rules

  1. The arithmetic expression is evaluated. Its value then replaces the current value of each occurrence of rsult, from left to right.
  2. If the arithmetic-expression consists of a single identifier or literal, the COMPUTE statement behaves like a MOVE statement with the single identifier or literal acting as the source operand and each result operand acting as a destination operand.
  3. For any rsult specification that includes the word rounded, the value of the expression is rounded before being moved to rsult.

Additional References

Examples

Each of the examples assume these data descriptions and initial values:

INITIAL VALUES 


03  ITEMA  PIC 999V99 VALUE 2.                      2.00 
03  ITEMB  PIC 999V99 VALUE 3.                      3.00 
03  ITEMC  PIC 999V99 VALUE 4.                      4.00 
03  ITEMD  PIC 999V99 VALUE 5.                      5.00

RESULTS

  1. No rounding: 


    COMPUTE ITEMC =                            ITEMC = 2.82 
   (ITEMA + 6) ** (.1 * ITEMD).

  2. With rounding: 


    COMPUTE ITEMC ROUNDED =                    ITEMC = 2.83 
   (ITEMA + 6) ** (.1 * ITEMD).

  3. The ON SIZE ERROR phrase: 


    COMPUTE ITEMB = (ITEMA * ITEMD) ** 3       ITEMB = 3.00 
   ON SIZE ERROR 
     MOVE 100 TO ITEMC.                    ITEMC = 100.00

  4. The NOT ON SIZE ERROR phrase: 


    COMPUTE ITEMB = (ITEMA * ITEMD) ** 2       ITEMB = 100.00 
   ON SIZE ERROR 
     MOVE 100 TO ITEMC 
   NOT ON SIZE ERROR 
     MOVE 200 TO ITEMC.                    ITEMC = 200.00

6.8.8 CONTINUE

Function

The CONTINUE statement indicates that no executable statement is present. It causes an implicit control transfer to the next executable statement.

Syntax Rule

The CONTINUE statement can be used wherever a conditional or imperative statement can be used.

General Rule

The CONTINUE statement causes an implicit control transfer to the next executable statement.

Example 


READ FILE-A 
  INVALID KEY 
    CONTINUE. 
MOVE ...

This example shows how CONTINUE can replace an INVALID KEY imperative statement. Control passes to the MOVE statement whether or not the INVALID KEY condition occurs.

6.8.9 DELETE

Function

The DELETE statement logically removes a record from a mass storage file.

file-name

is the name of a relative or indexed file described in the Data Division. It cannot be the name of a sequential or line sequential file or a sort or merge file.

stment

is one or more imperative statements executed for an invalid key condition.

stment2

is one or more imperative statements executed for a not invalid key condition.

Syntax Rules

  1. There cannot be an INVALID KEY phrase or a NOT INVALID KEY phrase for a DELETE statement that references a file in sequential access mode.
  2. There must be an INVALID KEY phrase if: (a) the file is not in sequential access mode and (b) there is no applicable USE AFTER EXCEPTION procedure.

General Rules

  1. The file must be open in I-O mode when the DELETE statement executes.
  2. For a file in sequential access mode, a successfully executed READ statement must be the last input-output statement executed for the file before the DELETE statement. The I/O system logically removes the record that the READ statement accessed.
  3. For a relative file in random or dynamic access mode, the I/O system logically removes the record identified by the file's RELATIVE KEY data item. If the file does not contain that record, an invalid key condition exists.
  4. For an indexed file in random access mode, the I/O system (logically removes the record identified by the file's primary record key data item. If the file does not contain that record, an invalid key condition exists.
  5. For an indexed file in dynamic access mode, the behavior depends on the DUPLICATES phrase of the RECORD KEY clause of the SELECT statement. If the primary key allows duplicates, Rule 2 applies. If the primary key does not allow duplicates, Rule 4 applies.
  6. After successful DELETE statement execution, the identified record has been logically removed from the file. It is no longer accessible.
  7. DELETE statement execution does not affect the contents of the record area. It also does not affect the contents of the data item referred to in the DEPENDING ON phrase of the file's RECORD clause.
  8. For sequential access files, DELETE statement execution does not affect the File Position Indicator.
  9. For dynamic access files, the File Position Indicator can point to the record to be deleted before the DELETE statement executes. In this case, once the DELETE statement executes, the File Position Indicator:
    In all other cases, the File Position Indicator is not affected by the execution of a DELETE statement.
  10. DELETE statement execution updates the value of the FILE STATUS data item for the file.
  11. If there is an applicable USE AFTER EXCEPTION procedure, it executes whenever an input or output condition occurs that would result in a nonzero value in the first character of a FILE STATUS data item. However, it does not execute if the condition is invalid key, and there is an INVALID KEY phrase. If the condition is not invalid key and no applicable USE AFTER EXCEPTION Declarative procedure exists, the run unit terminates abnormally.

See the rules for the INVALID KEY phrase, Section 6.6.10.

Technical Notes

Additional References

Previous Next Contents Index