用 Codex 把 COBOL 老代码迁到 Java/Python：GPT-6.1 Sol 实测步骤、推理强度怎么选、金额舍入坑

model_provider = "aicodewith"
model = "gpt-6.1-sol"
model_reasoning_effort = "low"

[model_providers.aicodewith]
name = "aicodewith"
base_url = "https://api.aicodewith.ai/chatgpt/v1"
wire_api = "responses"
experimental_bearer_token = "sk-你的Key"

       IDENTIFICATION DIVISION.
       PROGRAM-ID. INTEREST.
       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
           SELECT ACCT-FILE ASSIGN TO "accounts.dat"
               ORGANIZATION IS LINE SEQUENTIAL.
           SELECT TXN-FILE ASSIGN TO "txns.dat"
               ORGANIZATION IS LINE SEQUENTIAL.
       DATA DIVISION.
       FILE SECTION.
       FD  ACCT-FILE.
       01  ACCT-REC.
           05 A-ID          PIC X(4).
           05 A-RATE        PIC 9V9999.
       FD  TXN-FILE.
       01  TXN-REC.
           05 T-ID          PIC X(4).
           05 T-AMT         PIC 9(7)V99.
       WORKING-STORAGE SECTION.
       01  WS-EOF           PIC X VALUE "N".
       01  WS-N             PIC 99 VALUE 0.
       01  WS-I             PIC 99.
       01  WS-FOUND         PIC X.
       01  WS-TABLE.
           05 WS-ENT OCCURS 20 TIMES.
              10 WS-ID      PIC X(4).
              10 WS-RATE    PIC 9V9999.
       01  WS-INT           PIC 9(7)V99.
       01  WS-TOTAL         PIC 9(9)V99 VALUE 0.
       01  WS-MISS          PIC 99 VALUE 0.
       01  D-AMT            PIC Z,ZZZ,ZZ9.99.
       01  D-INT            PIC Z,ZZZ,ZZ9.99.
       01  D-TOT            PIC ZZZ,ZZZ,ZZ9.99.
       PROCEDURE DIVISION.
           OPEN INPUT ACCT-FILE
           PERFORM UNTIL WS-EOF = "Y"
               READ ACCT-FILE
                   AT END MOVE "Y" TO WS-EOF
                   NOT AT END
                       ADD 1 TO WS-N
                       MOVE A-ID TO WS-ID(WS-N)
                       MOVE A-RATE TO WS-RATE(WS-N)
               END-READ
           END-PERFORM
           CLOSE ACCT-FILE
           MOVE "N" TO WS-EOF
           OPEN INPUT TXN-FILE
           PERFORM UNTIL WS-EOF = "Y"
               READ TXN-FILE
                   AT END MOVE "Y" TO WS-EOF
                   NOT AT END PERFORM PROCESS-TXN
               END-READ
           END-PERFORM
           CLOSE TXN-FILE
           MOVE WS-TOTAL TO D-TOT
           DISPLAY "TOTAL INTEREST " D-TOT
           DISPLAY "MISSING ACCTS  " WS-MISS
           STOP RUN.
       PROCESS-TXN.
           MOVE "N" TO WS-FOUND
           PERFORM VARYING WS-I FROM 1 BY 1
                   UNTIL WS-I > WS-N OR WS-FOUND = "Y"
               IF WS-ID(WS-I) = T-ID
                   MOVE "Y" TO WS-FOUND
                   COMPUTE WS-INT = T-AMT * WS-RATE(WS-I)
                   ADD WS-INT TO WS-TOTAL
                   MOVE T-AMT TO D-AMT
                   MOVE WS-INT TO D-INT
                   DISPLAY T-ID " " D-AMT " INT " D-INT
               END-IF
           END-PERFORM
           IF WS-FOUND = "N"
               ADD 1 TO WS-MISS
               DISPLAY T-ID " MISSING ACCOUNT - SKIPPED"
           END-IF.

accounts.dat
A0010035
A0020125
A0030399

txns.dat
A001000123456
A002000099999
A009000050000
A003001234567
A001000000099

sudo apt-get install -y gnucobol
cobc -x INTEREST.cbl
./INTEREST > expected_output.txt

A001     1,234.56 INT        43.20
A002       999.99 INT       124.99
A009 MISSING ACCOUNT - SKIPPED
A003    12,345.67 INT     4,925.92
A001         0.99 INT         0.03
TOTAL INTEREST       5,094.14
MISSING ACCTS  01

codex exec "把 INTEREST.cbl 迁移成 Python 3（interest.py），要求输出和原 COBOL 程序逐字节一致（包括定点运算截断、金额格式、缺失账户处理）。expected_output.txt 是用 GnuCOBOL 编译运行原程序得到的真实输出。再写一个 test_parity.py：运行 interest.py，把 stdout 和 expected_output.txt 逐字节比较，并额外构造几条会暴露“四舍五入 vs 截断”差异的测试数据，用 cobc 编译原程序跑出期望值做对比。最后运行测试并报告结果。"

amount = number(record[4:13])
# No ROUNDED clause: discard fractional cents before adding to total.
# Assignment to unsigned PIC fields also discards excess high digits.
interest = (amount * rates[account] // 10_000) % 1_000_000_000
total = (total + interest) % 100_000_000_000