# 28-sysin — SYSIN Reading Simulation

## 电信业务场景

批量参数SYSIN读取。从SYSIN文件读取月次批处理参数(账期、报表类型、输出格式等)，控制批处理行为。

## Purpose
Demonstrates reading parameter cards from a SYSIN file (LINE SEQUENTIAL) in PARAM=VALUE format and using them to control program behavior.

## Test Coverage
1. **Normal parameters** — Read SORT-KEY, OUTPUT-FMT, MAX-RECORDS, etc.
2. **Multi-card reading** — Process multiple parameter cards sequentially
3. **Comments** — Lines starting with * or # are skipped
4. **Empty SYSIN** — File with no content uses defaults
5. **Format errors** — Missing '=', malformed cards are detected and counted
6. **Default values** — Parameters not specified retain their defaults

## Key Techniques
- LINE SEQUENTIAL file ORGANIZATION for SYSIN
- FUNCTION TRIM for whitespace handling
- FUNCTION UPPER-CASE for case-insensitive matching
- EVALUATE for parameter dispatch
- FILE STATUS checking (10 = end of file)