1

我正在读取输入文件并将其写入输出文件直到达到 EOF 但我的程序的问题是在输出文件中写入记录直到达到 EOF 输出文件包含与输入文件相比额外的一条记录，即如果输入文件包含 10 条记录，则输出文件包含 11 条记录。并且输出文件中的额外记录与最后一条记录相同，即最后一条记录重复两次。

所以你能告诉我我的代码有什么问题吗？

我的程序代码。

?SYMBOLS
?INSPECT

 IDENTIFICATION DIVISION.
 PROGRAM-ID. InsertRecords.
 AUTHOR. XYZ.


 ENVIRONMENT DIVISION.
 INPUT-OUTPUT SECTION.
 FILE-CONTROL.
      SELECT StudentRecords
             ASSIGN TO "=MKFIL1"
             ORGANIZATION IS SEQUENTIAL
             ACCESS       IS SEQUENTIAL
             FILE STATUS IS WS-FILE-STATUS.

      SELECT NEWStudentRecords
             ASSIGN TO "=MKFIL2"
             ORGANIZATION IS SEQUENTIAL
             ACCESS       IS SEQUENTIAL
             FILE STATUS IS WS-FILE-STATUS.

 DATA DIVISION.
 FILE SECTION.
 FD StudentRecords.
 01 StudentRecord.
   05 Student              PIC X(431).


 FD NewStudentRecords.
 01 NewStudentRecord        PIC X(431).


 WORKING-STORAGE SECTION.

 01 WS-DETAIL-RECORD          PIC X(431).

 01  EOF                      PIC X(3)  VALUE  "NO".

 01 WS-FILE-STATUS            PIC XX VALUE ZEROES.

 01 WS-SOURCE.
   05 PIC X(16) VALUE X"000102030405060708090A0B0C0D0E0F".
   05 PIC X(16) VALUE X"101112131415161718191A1B1C1D1E1F".
   05 PIC X(16) VALUE X"202122232425262728292A2B2C2D2E2F".
   05 PIC X(16) VALUE X"303132333435363738393A3B3C3D3E3F".
   05 PIC X(16) VALUE X"404142434445464748494A4B4C4D4E4F".
   05 PIC X(16) VALUE X"505152535455565758595A5B5C5D5E5F".
   05 PIC X(16) VALUE X"606162636465666768696A6B6C6D6E6F".
   05 PIC X(16) VALUE X"707172737475767778797A7B7C7D7E7F".
   05 PIC X(16) VALUE X"808182838485868788898A8B8C8D8E8F".
   05 PIC X(16) VALUE X"909192939495969798999A9B9C9D9E9F".
   05 PIC X(16) VALUE X"A0A1A2A3A4A5A6A7A8A9AAABACADAEAF".
   05 PIC X(16) VALUE X"B0B1B2B3B4B5B6B7B8B9BABBBCBDBEBF".
   05 PIC X(16) VALUE X"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF".
   05 PIC X(16) VALUE X"D0D1D2D3D4D5D6D7D8D9DADBDCDDDEDF".
   05 PIC X(16) VALUE X"E0E1E2E3E4E5E6E7E8E9EAEBECEDEEEF".
   05 PIC X(16) VALUE X"F0F1F2F3F4F5F6F7F8F9FAFBFCFDFEFF".

 01 WS-TARGET.
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"202122232425262728292A2B2C2D2E2F".
   05 PIC X(16) VALUE X"303132333435363738393A3B3C3D3E3F".
   05 PIC X(16) VALUE X"404142434445464748494A4B4C4D4E4F".
   05 PIC X(16) VALUE X"505152535455565758595A5B5C5D5E5F".
   05 PIC X(16) VALUE X"606162636465666768696A6B6C6D6E6F".
   05 PIC X(16) VALUE X"707172737475767778797A7B7C7D7E20".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".
   05 PIC X(16) VALUE X"20202020202020202020202020202020".


 PROCEDURE DIVISION.
 BEGIN.
    OPEN INPUT StudentRecords
    OPEN OUTPUT NewStudentRecords

    PERFORM UNTIL EOF = "YES"
    READ StudentRecords
       AT END MOVE "YES" TO EOF
    END-READ
          MOVE Student TO WS-DETAIL-RECORD
          INSPECT WS-DETAIL-RECORD CONVERTING WS-SOURCE TO WS-TARGET
              WRITE NewStudentRecord FROM WS-DETAIL-RECORD
    END-PERFORM
    CLOSE StudentRecords
    CLOSE NewStudentRecords
    STOP RUN.
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2 回答 2

2

COCOL在您尝试读取最后一条记录之前，您不知道您已达到 EOF 。

因此，当您读取最后一条记录时，EOF是 ((not** 设置为YES，因此下一个记录是“读取”。该读取失败并EOF设置为YES- 但您已经开始循环，因此缓冲区中的数据为又写了。

因此，您需要对EOF状态进行处理。就个人而言，我会将处理移至另一段并使用

PERFORM UNTIL EOF = "YES"
READ StudentRecords
   AT END MOVE "YES" TO EOF
END-READ
IF EOF = "NO" PERFORM NEW-PARAGRAPH
END-PERFORM
于 2014-11-03T15:59:46.307 回答
1

@Magoo 是正确的。

您已经FILE STATUS在您SELECT的 s 上进行了编码，使用它可以使事情变得更清晰。

为避免混淆，您应该对两个单独的FILE STATUS字段进行编码。

在FILE STATUS输入文件的字段中，将 a 编码88 (condition name)为 a VALUEof "10"。

OPEN input file, check file status is zero (another 88)
OPEN output file, check file status is zero (another 88)
Initial Processing
READ input file, check file status: if 10 (88) you have an empty file, 
     do something reasonable, else if non-zero, report it.
Loop until FILE STATUS field for input file is "10" (88)
  process input record
  Read input file
End-Loop
Final Processing check file status is zero (88)
CLOSE input file, check file status is zero (88)
All Done

这种技术，第一个READ被称为“启动读取”，可以防止使用AT END/NOT AT END或立即测试AT END刚刚设置的内容的纠结。

于 2014-11-03T17:35:03.257 回答