A user agent is a computer program representing a person, for example, a browser in a Web context.
Besides a browser, a user agent could be a bot scraping webpages, a download manager, or another app accessing the Web. Along with each request they make to the server, browsers include a self-identifying User-Agent HTTP header called a user agent (UA) string. This string often identifies the browser, its version number, and its host operating system.
Spam bots, download managers, and some browsers often send a fake UA string to announce themselves as a different client. This is known as user agent spoofing.
A typical user agent string looks like this: "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:35.0) Gecko/20100101 Firefox/35.0".
The Opera browser is also based on the Blink engine, which is why it almost looks the same, but adds “Or/
Platform identifiers change based on the operating system being used, and version numbers also increment as time passes. Mapping UA string tokens to a more human-readable browser name for use in code is a common pattern on the web today.
When mapping the new Edge token to a browser name, Microsoft recommends using a different name than the one developer used for the legacy version of Microsoft Edge to avoid accidentally applying any legacy workarounds that are not applicable to Chromium-based browsers. When Microsoft is notified about these types of issues, website owners are contacted and informed about the updated UA.
In these cases, Microsoft uses a list of UA overrides in our Beta and Stable channels to maximize compatibility for users who access these sites. The bad bots you definitely want to avoid as these consume your CDN bandwidth, take up server resources, and steal your content.
Good bots (also known as web crawlers) on the other hand, should be handled with care as they are a vital part of getting your content to index with search engines such as Google, Bing, and Yahoo. Read more below about some top 10 web crawlers and user agents to ensure you are handling them correctly.
However, there are also issues sometimes when it comes to scheduling and load as a crawler might be constantly polling your site. This file can help control the crawl traffic and ensure that it doesn't overwhelm your server.
Google bot is obviously one of the most popular web crawlers on the internet today as it is used to index content for Google's search engine. Patrick Sexton wrote a great article about what a Google bot is and how it pertains to your website indexing.
One great thing about Google's web crawler is that they give us a lot of tools and control over the process. Bingo is a web crawler deployed by Microsoft in 2010 to supply information to their Bing search engine.
Access pages from sites across the Web to confirm accuracy and improve Yahoo's personalized content for our users. DuckDuckGo is the Web crawler for DuckDuckGo, a search engine that has become quite popular lately as it is known for privacy and not tracking you.
These include hundreds of vertical sources delivering niche Instant Answers, DuckDuckGo (their crawler) and crowd-sourced sites (Wikipedia). They also have more traditional links in the search results, which they source from Yahoo!, Yandex and Bing.
Baidu spider is the official name of the Chinese Baidu search engine's web crawling spider. Mandelbrot is the web crawler to one of the largest Russian search engines, Yandex.
Soon Spider is the web crawler for Sogou.com, a leading Chinese search engine that was launched in 2004. Note: The Soon web spider does not respect the robots' exclusion standard, and is therefore banned from many websites because of excessive crawling.
Exact is a web crawler for Exiled, which is a search engine based out of France. Part of how this works on the Facebook system involves the temporary display of certain images or details related to the web content, such as the title of the webpage or the embed tag of a video.
One of their main crawling bots is Face bot, which is designed to help improve advertising performance. As you probably know they collect information to show rankings for both local and international sites.
You generally don't want to block Google or Bing from indexing your site unless you have a good reason. Key CDN released a new feature back in February 2016 that you can enable in your dashboard called Block Bad Bots.
Here are a couple of good resources in which you can lookup popular bad bots, crawlers, and scrapers. Sergeant strings come in all shapes and sizes, and the number of unique user agents is growing all the time.
If you need to integrate the user agent parser directly into your website or system then it's very simple to use the API. This will let you do things like advanced filtering and searching, identify trends in user agents, perform statistical analysis and other interesting applications.
Firefox OS phones say Mobile “; the web is the platform. On Desktop, gecko trail is the fixed string 20100101 Firefox/ firefoxversion indicates the browser is Firefox, and provides the version (such as 17.0 “).
For other products based on Gecko, the string can take one of two forms, where the tokens have the same meaning except those noted below: Appname / app version indicates the application name and version.
The platform part of the UA string indicates if Firefox is running on a phone-sized or tablet device. When Firefox runs on a device that has the phone form factor, there is a Mobile; token in the platform part of the UA string.
The preferred way to target content to a device form factor is to use CSS Media Queries. This way, your code will work if/when Firefox ships on other phone/tablet operating systems or Android is used for laptops.
Firefox OS devices identify themselves without any operating system indication; for example: “Mozilla/5.0 (Mobile; RV:15.0) Gecko/15.0 Firefox/15.0”. Starting in Version 6, users can opt into using a GeckoView-based Focus for Android with a hidden preference: it uses a GeckoView UA string to advertise Gecko compatibility.
Klein Version (Rendering Engine) Sergeant string1.0 (Review)Mozilla/5.0 (Linux; Android 7.0) Apple WebKit/537.36 (HTML, like Gecko) Version/4.0 Klein/1.0 Chrome/58.0.3029.83 Mobile Safari/537.364.1+ (Review)Mozilla/5.0 (Linux; Android 7.0) Apple WebKit/537.36 (HTML, like Gecko) Version/4.0 Focus/4.1 Chrome/62.0.3029.83 Mobile Safari/537.366.0+ (GeckoView)Mozilla/5.0 (Android 7.0; Mobile; RV:62.0) Gecko/62.0 Firefox/62.0 Version 7 of Focus for iOS uses an user agent string with the following format: Note: this user agent was retrieved from an iPhone XR simulator and may be different on device.
Firefox for Echo Show version User agent string v1.1Mozilla/5.0 (Linux; Android 5.1.1) Apple WebKit/537.36 (HTML, like Gecko) Version/4.0 Focus/1.1 Chrome/59.0.3017.125 Safari/537.36 Form factorGecko user agent stringPhoneMozilla/5.0 (Mobile; RV:26.0) Gecko/26.0 Firefox/26.0TabletMozilla/5.0 (Tablet; RV:26.0) Gecko/26.0 Firefox/26.0TVMozilla/5.0 (TV; RV:44.0) Gecko/44.0 Firefox/44.0Device-specificMozilla/5.0 (Mobile; NNN; RV:26.0) Gecko/26.0 Firefox/26.0 Some of them we have noticed are of the form Nelson; “, Reopen; “, or Open C; (note that putting space is also discouraged).
Firefox OS version numberGecko version number1.0.118.01.118.11.226.01.328.01.430.02.032.02.134.02.2372.544It's easy to find the correspondences by looking at the Mercurial repository names : repositories starting by mozilla-b2g are the release repositories for Firefox OS, and have both Firefox OS and Gecko versions in their names. The first two digits are owned by the Mozilla product team and denote versions with new features (e.g.: v1.1, 1.2, etc).
The third digit is incremented with regular version tags (about every 6 weeks) for security updates, and the fourth is owned by the OEM. BrowserGecko user agent string Firefox for Memo (Nokia N900)Mozilla/5.0 (Memo; Linux armv7l; RV:10.0.1) Gecko/20100101 Firefox/10.0.1 Fennec/10.0.1Camino on Mac Mozilla/5.0 (Macintosh; Intel Mac OS X 10.5; RV:2.0.1) Gecko/20100101 Firefox/4.0.1 Camino/2.2.1SeaMonkey on Windows Mozilla/5.0 (Windows NT 5.2; RV:10.0.1) Gecko/20100101 Firefox/10.0.1 Monkey/2.7.1SeaMonkey on Mac Mozilla/5.0 (Macintosh; Intel Mac OS X 10.5; RV:10.0.1) Gecko/20100101 Firefox/10.0.1 Monkey/2.7.1SeaMonkey on Linux Mozilla/5.0 (X11; Linux i686; RV:10.0.1) Gecko/20100101 Firefox/10.0.1 Monkey/2.7.1Prior to Firefox 4 and Gecko 2.0, it was possible for extensions to add user agent parts through the general.user agent.extra.
Identifier preferences, (see the obsolete Sergeant Strings Reference). In the past, specific plug-ins, add-ons or extensions added user agent parts to notify sites they were installed.
The recommended way to do this, if it's absolutely necessary (remember that it slows down every request) is to set a custom HTTP header. The client provides a graphical user interface containing fields for entering the sender and recipient addresses, the subject of the message and the message itself.
Furthermore, the domain part of the recipient's address must be the canonical names of the SMTP server handling incoming mail at the recipient's site. MailClientThe user interfaceMessageMail messageEnvelopeSMTP envelope around the MessageSMTPConnection Connection to the SMTP servery will need to complete the code in the SMTPConnection class so that in the end you will have a program that is capable of sending mail to any recipient.
The places where you need to complete the code have been marked with the comments /* Fill in */. For the basic interaction of sending one message, you will only need to implement a part of SMTP.
Section 2.4 of the text provides a more complete description of SMTP, but in this lab you need only to implement the commands in the following table. For simplicity, you can assume that any other reply from the server indicates a fatal error and abort the sending of the message.
In reality, SMTP distinguishes between transient (reply codes 4xx) and permanent (reply codes 5xx) errors, and the sender is allowed to repeat commands that yielded in a transient error. In addition, when you open a connection to the server, it will reply with the code 220.
Note: RFC 821 allows the code 251 as a response to a RCPT TO-command to indicate that the recipient is not a local user. You may want to verify manually with the telnet command what your local SMTP server replies.
To make it easier to debug your program, do not, at first, include the code that opens the socket, but use the following definitions for observer and server. Acting as the SMTP server, you will need to give the correct reply codes.
When your program works, add the code to open the socket to the server. In the function parseReply(), you should use the StringTokenizer -class for parsing the reply strings.
You will need to modify also the other classes (Millicent, Message, and Envelope). Java's System-class contains information about the username and the InetAddress-class contains methods for finding the name of the local host.
The generated mails have only four header fields, From, To, Subject, and Date. Currently, the program only allows sending mail to a single recipient.
For a more challenging exercise, modify the program to send mail to an arbitrary number of recipients. The provided code assumes that all errors that occur during the SMTP connection are fatal.
This exercise may require large modifications to the send(), sendCommand(), and parseReply() functions. Your report should discuss SMTP as a protocol and what you implemented in this project.
Provide a listing of the software and clearly show the code that you have added to the original. For Extra credit in the 8560 Class, your mail agent needs to support multipart mime extensions and attachments.
Drop the Rule Direction and select Client to Server. Once added, Apply the changes for each screen until you get back to the Configure Multi-Protocol Gateway Style Policy panel.
Select Transform with XSLT style sheet for the Use Document Processing Instructions. In the Transform File section drop the first drop section to select local:///GetStat (if the GetS tat folder if not available, open the File Management section in another browser window to add the GetS tat subfolder under local:///).
The code could be found in the appendix section titled setDeviceName.xsl at the bottom of this doc. 12. getMem.js : The getter script is a gateway script which will invoke the current appliances REST interface to pull the memory usage statistics.
Continue the same steps to add the other scripts to run the other REST APIs. NOTE: Be mindful of the REST API URI, some will require different domains, such as the getServicesMemStatus.js in the appendix.
Double-click on the Advanced Action, select the Set Variable action type and click Next. Once complete, click on Done and Apply Changes in the Processing Policy.
After all the changes, you should be back in the main Mpg, Apply the changes, and Save Config. Add a new XML Manager by clicking the add (+) icon under the XML Manager section, and when the Configure XML Manager pops up, enter a name for the XML (e.g. getStat_XMLM), then locate the Sergeant Configuration section and click on the add (+) icon to create a new Sergeant.
Information: The Sergeant is where you specify the SSL Profile and Basic Auth to be used. In the Sergeant section, name the Sergeant (e.g. GetStat_UserAgent), click on the SSL Profile Policy tab, and inside the SSL Profile Policy section click on the Add button to create a new Client Profile.
Then in the SSL client profile section, click on the add (+) icon, and when the Configure SSL Client Profile pops up, name the object (e.g. emptySSLClientProfile), and configure the following for the SSL Client Profile: Continue to Apply all the panels until you reach the Configure Sergeant pop up again.
In the Sergeant pop up, select the Basic-Auth Policy tab and enter the privileged user and password for the basic authentication. Apply and click Save Config for the Mpg.
Create an HTTP Front Side Protocol and ensure the GET method is enabled. Apply the changes to the HTTP Front side Handler and Save Config.