题解 | #netstat练习2-查看和3306端口建立的连接#

#! /usr/bin/env bash

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#
#
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function solution_1() {
    grep ESTABLISHED nowcoder.txt | grep 3306 | awk -F":" '{print $2}' | awk '{print $2}' | sort | uniq -c | awk '{print $1,$2}' | sort -nr -k1
}

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#
#
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function solution_2() {
    awk '{
        if($6 = /ESTABLISHED/ && $5 ~ /3306/) a[substr($5,1,index($5,":")-1)]++
    } END {
        for(k in a) {
           print a[k],k
       }
    }' nowcoder.txt | sort -nrk1
}

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#
#
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function solution_3() {
    local condition_index=${1}
    local target_index=${2}

    declare -A map
    local array=""
    local str=""
    while read line; do
        array=(${line})
        str="${arr[${target_index}]}"
        if [[ "${array[${condition_index}]}" = "ESTABLISHED" ]]; then
            str=${str:(-4)}
            if [[ "${str}" = "3306" ]]; then
                ((map["${str}"]++))
            fi
        fi
    done < nowcoder.txt
    echo "map keys: ${!map[@]}"
    echo "map values: ${map[@]}"
    
    local tmp=(${map[@]})
    local size=${#tmp[@]}
    local int=0
    for (( i = 0; i < ${size}; i++ )); do
        for (( j = $i + 1; j < ${size}; j++ )); do
            [[ ${tmp[$i]} -ge ${tmp[$j]} ]] && continue
            int=${tmp[$i]}
            tmp[i]=${tmp[$j]}
            tmp[$j]=$int
        done
    done

    for (( i = 0; i < size; i++ )); do
        for va in ${!map[*]}; do
            [[ ${tmp[$i]} = ${map[$va]} ]] && printf "${map[$va]} $va\n"
        done
    done
}

#solution_1
solution_2
#solution_3 5 4