"HTTP" Fiddler (i)-Fiddler introduction

Reprinted from: Http://blog.csdn.net/ohmygirl/article/details/178461991. Why is fiddler?

Grasping contractor has many, small to the most commonly used Web Debugging tools Firebug, to reach the universal powerful grab bag tool Wireshark. Why use fiddler? For the following reasons:

Although A.firebug can grab packets, it is not powerful enough to parse the details of an HTTP request. The ability to simulate HTTP requests is not enough, and firebug often requires "No refresh modification", and if the page is refreshed, all modifications are not saved.

B.wireshark is a generic grab kit, but it's huge and seems a bit overqualified for applications that only need to crawl HTTP requests.

C.httpwatch is also a more commonly used HTTP capture tool, but only supports IE and Firefox browser (other browsers may have a corresponding plug-in), for want to debug Chrome browser HTTP request, seems to be a little weak, and Fiddler2 is a use of local 127.0.0.1:8888 HTTP proxy, any browser and application that can set the HTTP proxy to 127.0.0.1:8888 can use Fiddler.

2. What is Fiddler?

Fiddler is the HTTP proxy on the client and server side, and is one of the most commonly used HTTP capture tools. It can record all HTTP requests between client and server, can analyze request data for specific HTTP request, set breakpoints, debug Web application, modify requested data, even can modify the data returned by the server, it is very powerful, it is the tool of Web debugging.

Since it is the agent, that is to say: All the client's request to go through fiddler, and then forwarded to the appropriate server, conversely, the server side of all the response, will go through fiddler and then sent to the client, for this reason, Fiddler supports all browsers and applications that can set the HTTP proxy to 127.0.0.1:8888. After using fiddler, the Web client and server requests are as follows:

Fiddler as a system agent, when the Fiddler is enabled, the proxy setting of IE will become 127.0.0.1:8888, so if your browser does not set the appropriate proxy after the Fiddler is turned on, then Fiddler cannot capture the HTTP request. The following is the proxy settings for Internet Explorer after starting fiddler:

In Firefox, for example, Firefox is not enabled by default (if you have proxy tools or plug-ins installed like proxy), the steps to configure the HTTP proxy in Firefox are as follows:

Settings, network-I, advanced, tools, options. and configure the appropriate agents as follows:

You can use Fiddler to crawl the Firefox HTTP request.

3.Fiddler User Interface Introduction

The layout of the Fiddler main interface is as follows:

The main interface consists of four commonly used blocks:

1.Fiddler menu bar, green section. This includes capturing HTTP requests, stopping capture requests, saving HTTP requests, loading local sessions, setting capture rules, and so on.

2.Fiddler toolbar, red section. Includes fiddler actions for the current view (pause, clear Session,decode mode, clear cache, and so on).

3.web session panel, yellow area, mainly fiddler crawl to each HTTP request (each called a session), mainly contains the requested URL, protocol, status code, body and other information, the detailed field meaning as shown:

4. Details and data statistics panel. Specific statistics for each HTTP request (such as the number of bytes sent/received, the Send/Receive time, and a rough count of the time spent accessing the server around the world) and packet analysis. such as the Inspector panel, provides headers, TextView, Hexview,raw and other ways to view the request message of a single HTTP request:

Under the composer panel, you can simulate the process of sending data to the appropriate server (yes, this is the basic principle of the irrigation robot, or it can be a way of partial HTTP flood).

You can also paste the requested raw HTTP headers to achieve the purpose of the impersonation request:

The filter tag can be used to filter HTTP requests by setting the Fiddler filtering rules. The simplest example: Filter the intranet HTTP request to crawl only the Internet HTTP request, or filter the corresponding domain name of the HTTP request. Fiddler filters are very powerful, can filter requests for specific HTTP status codes, can filter HTTP requests for specific request types (such as CSS requests, image requests, JS requests, etc.), and can filter requests with a request message greater than or less than a specified size (byte):

Many filter rules require a step-by-step excavation.

"HTTP" Fiddler (i)-Fiddler introduction