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/*
* wiki-philosophy.js
* How many clicks does it take to get from any word to Philosophy on Wikipedia?
*
* Copyright 2011 Jason A. Donenfeld <Jason@zx2c4.com>
*
*/
var jsdom = require("jsdom");
if (process.argv.length <= 2)
return console.error("Usage: " + process.argv[0] + " " + process.argv[1] + " word [target]");
// Keep track of links we've followed to prevent infinite loops.
var searchedWords = [];
// We use a queue so that we can simulate a BFS of the tree.
var linkQueue = []
var found = false;
var maxParallelRequests = 30;
var currentRequests = 0;
var jQuery = require("fs").readFileSync("./jquery-1.6.2.min.js").toString();
var targetWord = "Philosophy"
function search(page)
{
if (searchedWords.indexOf(page.word) != -1)
return; // Already searched!
searchedWords.push(page.word);
++currentRequests;
jsdom.env({ html: "http://en.wikipedia.org/wiki/" + stringToWikiurl(page.word), src: [jQuery], done: function (errors, window) {
--currentRequests;
if (found)
return;
console.log("Fetched " + page.word);
var $ = window.$;
if ($ === undefined || $ == null) {
console.error("jQuery failed to load");
return;
}
if ($("#bodyContent .redirectMsg").length > 0) {
// This page is a redirect page, follow the redirect
var components = $("#bodyContent .redirectText > a").attr("href").split('/');
appendToQueue({ word: wikiurlToString(components[components.length - 1]), parent: page });
} else {
// Find all links in the content and add them to stack.
var found = false;
var process = function (i, ele) {
var components = $(ele).attr("href");
if (components.indexOf("/wiki/") != 0)
return true;
components = components.split('/');
components = components[components.length - 1];
if (components.indexOf("Wikipedia") == 0 ||
components.indexOf("File:") == 0 ||
components.indexOf("Category:") == 0 ||
components.indexOf("Help:") == 0 ||
components.indexOf("Special:") == 0)
return true;
found = true;
appendToQueue({ word: wikiurlToString(components), parent: page });
};
$.each($("#bodyContent > p a"), process);
// Disambiguation page
if (!found)
$.each($("#bodyContent a"), process);
}
// Keep queuing pages.
runQueue();
// Free up jsdom's memory leak:
// https://github.com/mikeal/spider/issues/5#issuecomment-1830243
window.close();
}});
}
function appendToQueue(page)
{
if (page.word == targetWord) {
found = true;
done(page);
return;
}
linkQueue.push(page);
}
function runQueue()
{
while (linkQueue.length > 0 && !found && currentRequests < maxParallelRequests)
search(linkQueue.shift());
}
function done(page)
{
console.log("\n== " + targetWord + " found, sophia achieved! ==\n");
// Walk tree backwards to make list.
var list = []
while (page != null) {
list.unshift(page);
page = page.parent;
}
for (var i = 0; i < list.length; ++i) {
var indent = "";
for (var j = 0; j < i; ++j)
indent += '\t';
console.log(indent + list[i].word);
}
process.exit(0);
}
function wikiurlToString(wiki)
{
return wiki.replace(/_/g, " ");
}
function stringToWikiurl(string)
{
return string.replace(/ /g, "_");
}
// Grab the starting word.
if (process.argv.length == 4)
targetWord = process.argv[3][0].toUpperCase() + process.argv[3].slice(1);
appendToQueue({ word: process.argv[2][0].toUpperCase() + process.argv[2].slice(1), parent: null });
runQueue();
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