如何用Bash字典实现Bash历史命令计数器？求修正报错代码

问题说明 #

我尝试编写一个Bash脚本，用关联数组存储命令（键）和对应的使用次数（值），统计Bash历史中最常用的命令，但当前代码无法正常运行。以下是相关代码和输出示例：

错误的Bash代码 #

#!/bin/bash
clear

Counter() {
    declare -A dict

    while read line; do
        if [[ -n "${dict[$line]}" ]]; then
            ((${dict[$line]}+1))
        else
            dict["$line"]=1
        fi
    done < /home/$USER/.bash_history

    echo ${!dict[@]} ${dict[@]}
}

Counter

参考Python代码 #

def Counter(file):
    dict = {}
    for line in file.read().splitlines():
        if line not in dict:
            dict[line] = 1
        else:
            dict[line] += 1

    for k, v in sorted(dict.items(), key=lambda x: x[1]):
        print(f"{k} was used {v} times")

with open("/home/igor/.bash_history") as bash:
    Counter(bash)

参考输出格式 #

echo $SHELL was used 11 times
sudo apt-get update was used 14 times
ls -l was used 14 times
ldd /opt/pt/bin/PacketTracer7 was used 15 times
zsh was used 17 times
ls was used 26 times

正确的Bash脚本 #

#!/bin/bash

Counter() {
    declare -A cmd_counts

    # 读取bash历史，跳过空行
    while IFS= read -r line; do
        [[ -z "$line" ]] && continue
        # 计数自增，不存在则自动初始化为0再加1
        ((cmd_counts["$line"]++))
    done < "$HOME/.bash_history"

    # 将关联数组转换为"次数 命令"格式，排序后输出
    for cmd in "${!cmd_counts[@]}"; do
        echo "${cmd_counts[$cmd]} $cmd"
    done | sort -n | awk '{count=$1; $1=""; printf "%s was used %d times\n", substr($0,2), count}'
}

Counter

关键修改说明 #

1. 计数逻辑修复：原代码中的((${dict[$line]}+1))仅执行算术运算，未将结果存回数组。改用((cmd_counts["$line"]++))，会自动为不存在的键初始化为0并完成自增，无需额外判断。
2. 空行处理：增加[[ -z "$line" ]] && continue跳过历史文件中的空行，避免统计无效条目。
3. 排序与格式化输出：将键值对转换为"次数 命令"的单行格式，用sort -n按数字排序，最后通过awk调整为参考输出的格式。

内容的提问来源于stack exchange，提问作者IgorTheOverlord