有人说想要个拆分Shell命令和参数的工具，转义只需要支持\" \'

ShellArgs.java

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

enum State {
    NORMAL,SPACE,SINGLE,DOUBLE,ESCAPE
}

class Extractor {
    private State state; // 当前状态
    private String input; // 纸带
    private int index; // 位置
    private StringBuilder buffer; // 缓冲区
    private List<String> result; // 运行结果
    private State preState; // 转义之前的状态

    // 初始化状态机
    private Extractor(String input) {
        state = State.NORMAL;
        preState = State.NORMAL;
        this.input = input;
        index = 0;
        buffer = new StringBuilder();
        result = new ArrayList<>();
    }

    // 正常状态
    private void normalState() {
        switch (input.charAt(index)) {
            case ' ':
                state = State.SPACE;
                result.add(buffer.toString());
                buffer = new StringBuilder();
                break;
            case '\'':
                state = State.SINGLE;
                break;
            case '\"':
                state = State.DOUBLE;
                break;
            case '\\':
                preState = state;
                state = State.ESCAPE;
                break;
            default:
                state = State.NORMAL;
                buffer.append(input.charAt(index));
        }
    }

    // 空格状态
    private void spaceState() {
        switch (input.charAt(index)) {
            case ' ':
                state = State.SPACE;
                break;
            case '\'':
                state = State.SINGLE;
                break;
            case '\"':
                state = State.DOUBLE;
                break;
            case '\\':
                preState = state;
                state = State.ESCAPE;
                break;
            default:
                state = State.NORMAL;
                buffer.append(input.charAt(index));
        }
    }

    // 单引号状态
    private void singleState() {
        switch (input.charAt(index)) {
            case '\'':
                state = State.NORMAL;
                break;
            case '\\':
                preState = state;
                state = State.ESCAPE;
                break;
            case ' ':
            case '\"':
            default:
                state = State.SINGLE;
                buffer.append(input.charAt(index));
        }
    }

    // 双引号状态
    private void doubleState() {
        switch (input.charAt(index)) {
            case '\"':
                state = State.NORMAL;
                break;
            case '\\':
                preState = state;
                state = State.ESCAPE;
                break;
            case ' ':
            case '\'':
            default:
                state = State.DOUBLE;
                buffer.append(input.charAt(index));
        }
    }

    // 转义字符状态
    private void escapeState() {
        state = preState;
        buffer.append(input.charAt(index));
    }

    // 运行
    public static List<String> convert(String command) {
        Extractor extractor = new Extractor(command);
        for (int i = 0; i < command.length(); i++) {
            // 走带
            extractor.index = i;

            // 触发状态
            switch (extractor.state) {
                case NORMAL:
                    extractor.normalState();
                    break;
                case SPACE:
                    extractor.spaceState();
                    break;
                case SINGLE:
                    extractor.singleState();
                    break;
                case DOUBLE:
                    extractor.doubleState();
                    break;
                case ESCAPE:
                    extractor.escapeState();
            }
        }
        // 写入最后一个结果
        extractor.result.add(extractor.buffer.toString());

        // 如果引号未闭合
        if (extractor.state == State.SINGLE || extractor.state == State.DOUBLE) {
            System.out.println("检测到未闭合的引号，请检查该命令是否合法: " + extractor.input);
        }

        return extractor.result;
    }
}

public class ShellArgs {
    public static void main(String[] args) {
        while (true) {
            Scanner sc = new Scanner(System.in);
            System.out.print("nindeDianNao:~ nin$ > ");
            String command = sc.nextLine();
            System.out.println(Extractor.convert(command));
        }
    }
}