NB-076
71 lines
2.6 KiB
Markdown
71 lines
2.6 KiB
Markdown
# 29-ascii-ebcdic: ASCII to EBCDIC Encoding Conversion
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## 电信业务场景
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ASCII→EBCDIC主机编码转换。通过内建转换表将ASCII编码的CDR数据转换为EBCDIC编码，用于与大型主机系统交换数据。
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## Description
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Reads an ASCII-encoded sequential file and converts each byte to its
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EBCDIC equivalent using an internal conversion table defined via
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REDEFINES. The output file contains the EBCDIC-encoded data.
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**Note:** GnuCOBOL internally uses ASCII encoding. This program
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demonstrates a manual encoding conversion algorithm for scenarios
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where EBCDIC output is required for legacy system compatibility.
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## Conversion Table
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The 128-entry ASCII-to-EBCDIC table is initialized from REDEFINES
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data at program start. It covers:
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- Control characters (X'00'-X'3F') mapped to their EBCDIC equivalents
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- Printable characters (X'20'-X'7F') mapped per standard conversion
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- Characters >= X'80' are passed through unchanged
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## Record Layout
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### Input / Output (80 bytes fixed-length)
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| Structure | Type | Description |
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|-----------|----------|--------------------------------------|
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| IN-BYTE | OCCURS | Individual bytes for conversion |
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## Files
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| File | Purpose |
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|-------------------------|--------------------------------|
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| main-29-ascii-ebcdic.cbl | Main COBOL program |
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| data-gen.sh | Generate ASCII test data |
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| run.sh | Compile, run, verify |
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| README.md | This file |
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## Tests
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| Test Case | Description |
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|----------------------------|------------------------------------|
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| Uppercase A-Z | Letters mapped to EBCDIC |
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| Lowercase a-z | Lowercase mapped to EBCDIC |
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| Digits 0-9 | Numeric characters converted |
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| Printable symbols | Symbols like !@#$% converted |
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| Mixed content | Combination of letters/numbers |
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| Control characters | Preserved through conversion |
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| Space-padded record | Padding character handling |
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| All printable chars | Full ASCII printable range test |
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## Usage
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```bash
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cd 29-ascii-ebcdic
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bash data-gen.sh
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bash run.sh
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```
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## Expected Behavior
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- Input and output are the same size (8 records x 80 bytes each).
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- ASCII character 'A' (X'41') maps to EBCDIC X'C1'.
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- ASCII character '0' (X'30') maps to EBCDIC X'F0'.
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- Control characters (X'00'-X'1F') are converted per EBCDIC mapping.
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- Non-ASCII bytes (>= X'80') pass through unchanged.
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