![]() The full user agent string is a full description of the crawler, and appears inĬaution: The user agent string can be spoofed. This list is not complete, but covers most crawlers you might see on your website. One token, as shown in the table you need to match only one crawler token for a rule toĪpply. To match a crawler type when writing crawl rules for your site. The user agent token is used in the User-agent: line in robots.txt How you may see in your referrer logs, and how to specify them in The following tables show the Google crawlers and fetchers used by various products and services, Is used to automatically discover and scan websites by following links from one web page toįetchers, like a browser, are tools that request a single URL when prompted by a user. "Crawler" (sometimes also called a "robot" or "spider") is a generic term for any program that ![]() Google uses crawlers and fetchers to perform actions for its products, either automatically or Page.find('div.gtxt_body, div.gtxt_column, div.gtxt_footnote').Overview of Google crawlers and fetchers (user agents) Text is in 'gtxt_body', 'gtxt_column' and 'gtxt_footnote' Extract and save the text of the book page to the file Var page = $('div.flow:has(a), div.flow:has(a)') Use ^ to match pages because sometimes page ids can have a trailing hyphen and extra characters each of which contains an 'a' element where id is equal to the page Pages are contained within 'div' elements (where class='flow'), Var filename = pg.slice(0, 2) + number + '.txt' Var pg = url.slice(url.indexOf('pg=') + 3, url.indexOf('&output=text')) because a retrieved html page contains multiple book pages We will use this to only extract the text from this book page Extract the pg parameter (book page) from the url Cannot guarantee the execution order of the callback for each url, therefore save results to separate files request function is asynchronous, hence requirement for self-executing function Var urls = fs.readFileSync(input).toString().split('\n') Read the url input file, each url is on a new line and output (optional) is the directory where the output files will be saved where input (mandatory) is the text file containing your list of urls So far I have successfully scraped the first two volumes, five more to go! The code is given below, it may serve as a useful starter for scraping other Google books. This way I could quickly construct a text file using a spreadsheet program with the urls for each single page in order (because the increment is only 1). I got around this by using a jquery selector to only select the individual book page specified in the url and to ignore the other book pages present in the html. Therefore if we increment the page parameter in the url only by 1 then we would be scraping duplicate book pages if we are not careful (this was the part I was particularly stuck on). I used this page to help me: Įach html page contains multiple book pages. I solved this problem by writing a small program (called extract.js) in node.js to scrape the text. Also, I tried iRobot, GreaseMonkey and FoxySpider. I tried wget but receive a 401 unathorized access error. I have considered node.js and scrapy amongst many other things. I can program in Java and JavaScript and I have basic knowledge of Python. The initial url for volume 1 of the book is: So, I cannot necessarily predict the next url. The page increment is not always consistent, it can vary because some pages have embedded images. Navigating the pages is done by clicking continue or an arrow. Once I have the data (even if it is only the raw html pages), I'm sure I could use a parser to extract what I want. It is really part (1) that I am most stuck on. I do not want to waste more time on a dead end. I feel overwhelmed and do not know where to start or which is the best / easiest method to employ. I have already spent much time researching the tools and techniques that could be used to complete this task. We will be putting the text into a database, so we need the raw text rather than the pdf. The book in question is a very old book and is out of copyright. For my work, I need to scrape the text from a large book on Google Books.
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