#!/bin/bash

set -euo pipefail

echo "开始测试循环..."

data="line1
line2
line3"

echo "数据行数: $(echo "$data" | wc -l)"

echo "进入循环..."
count=0
while IFS= read -r line; do
    ((count++))
    echo "处理第 $count 行: $line"
    if [[ $count -eq 1 ]]; then
        echo "只处理第一行，退出测试"
        break
    fi
done <<< "$data"

echo "循环结束"