shell 脚本计算距离最近的坐标

坐标数据文件geo.log格式如下：

beijing(116.405285,39.904989)
tinajin(117.190182,39.125596)
hebei(114.502461,38.045474)
shanxi(112.549248,37.857014)
neimenggu(111.670801,40.818311)
liaoning(123.429096,41.796767)
jilin(125.3245,43.886841)
heilongjiang(126.642464,45.756967)
shanghai1(121.472644,31.231706)
jiangsu(118.767413,32.041544)
zhejiang(120.153576,30.287459)
anhui(117.283042,31.86119)
fujian(119.306239,26.075302)
jiangxi(115.892151,28.676493)
shandong(117.000923,36.675807)
henan(113.665412,34.757975)
hubei(114.298572,30.584355)
hunan(112.982279,28.19409)
guangdong(113.280637,23.125178)
guangxi(108.320004,22.82402)
hainan(110.33119,20.031971)
chongqing(106.504962,29.533155)
sichuan(104.065735,30.659462)
guizhou(106.713478,26.578343)
yunnan(102.712251,25.040609)
xizang(91.132212,29.660361)
shanxi3(108.948024,34.263161)
gansu(103.823557,36.058039)
qinghai(101.778916,36.623178)
ningxia(106.278179,38.46637)
xinjiang(87.617733,43.792818)
taiwan(121.509062,25.044332)
xianggang(114.173355,22.320048)
aomen(113.54909,22.198951)

编写脚本文件 coordinate.sh

#!/bin/bash

# 计算两点之间的距离
function distance {
    x1=$1
    y1=$2
    x2=$3
    y2=$4
    echo "scale=2; sqrt(($x2 - $x1)^2 + ($y2 - $y1)^2)" | bc
}

# 检查参数是否传入
if [ -z "$1" ] || [ -z "$2" ]; then
    echo "Usage: $0 <coordinates file> <point name>"
    exit 1
fi

# 从文件中读取坐标点并计算最近的点
while IFS='(' read -r name rest; do
    name=$(echo $name | tr -d ' ')  # 去除空格
    rest=$(echo $rest | tr -d ')')  # 去除右括号
    IFS=',' read -r x y <<< "$rest"
    if [ "$name" = "$2" ]; then
        xA=$x
        yA=$y
    else
        dist=$(distance $xA $yA $x $y)
        if [ -z "$minDistance" ] || (( $(echo "$dist < $minDistance" | bc -l) )); then
            minDistance=$dist
            closestPoint=$name
        fi
    fi
done < "$1"  # 从传入的文件中读取坐标点

echo "距离 $2 最近的点是 $closestPoint，距离为 $minDistance"