Web:3, httpd message Syntax format

URL: Unifrom Resource Locator

URL scheme: scheme

Server address: Ip:port

Resource path:

http://www.magedu.com:80/bbs/index.php

Basic syntax:

<scheme>://<user>:<password>@

params: Parameters

HTTP protocol: Stateless stateless

Server does not continuously track visitor sources

cookie,session Track and save user browsing information,

HTTP transaction:

requests: request

Response: Response

Message Syntax format :

Request message:

<method> <request-URL> <version> # start line

<entity-body> #实体

Response message:

<version> <status> <reason-phrase>

Status Code reason phrase

<entity-body>

<method>: Request method, desired action on server side, such as, post, etc.

Get: Get a resource from the server

HEAD: Get the document's response header from the server only

POST: Send the data to the server for processing:

Put: Stores the body portion of the request on the server,

Delete: Request to delete the specified document on the server

TRAACE: Tracking request arrives at the Server intermediate proxy server

OPTIONS: Request server returns the request method used for the specified resource support

<request-url>: Requested resource, can be a relative path, or it can be a full URL

<version>: protocol version, Format http/<major>. <minor>, as http/1.0

: HTTP Header

<status>: status code

<reason-phrase>: Cause phrase, number status, easy-to-read information

<entity-body>: The main part

Tools for viewing or analyzing protocols:

Tcpdump,tshark,wireshark

version:http/<major>.<minor>

Status (state code):

Three digits, such as 200,301,302,404,502; Mark what happens during request processing

1XX: Information Alert status Code

100-101

2XX: Success Status Code

200:ok

201:created OK

3XX: Redirect Status code

301:moved permanebtly Permanent redirect, using the header "Location:url" in the response message to specify where the resource is now

302:found temporary redirect, specifying the temporary resource location using the header "Location:url" in the response message

304:not Modified, using in conditional requests

4XX: Client-side error

403:forbidden, request rejected by server

404:not Found, the server could not find the requested URL

405:method not allowed, which does not allow a URL to request a response using this method

5XX: Error in server class

500:internal server error, internal errors

502:bad Gateway: Proxy server receives a pseudo response from upstream

503:service unavailable, the server cannot provide services at this time, but may be available in the future

reason-phrase: A brief description of the status marked by the status code

headers: Each request or response message can contain any header, each header has a header name, followed by a colon and followed by an optional space followed by a value

entity-body: data when the request is attached to the data or response

Headers ( HTTP header) Classification:

Format:

Name:value

General Header :

Date: The time the message was created

Connection: Connection mode, e.g. keep-alive

Via: Displays the middle node through which the message passed

Cache-control: Controlling the cache

Pragma

Request Header

The user indicates that the customer is more inclined to support the use of the ability

Accept: Notifies the server of the type of media it can receive

Accept-charset: Character Set

Accept-encoding: Notifies the server of the encoding format it can receive itself. such as Gzip

Accept-language: Language

Informational Request Header:

CLIENT-IP:

Host: The requested server name and port number

Referer: Contains the top level resource for the resource that is currently being requested

User-agent: Client proxy type

Conditional Request Header:

Expect: Expected behavior

If-modified-since: Whether this resource has been modified since the specified time

If-unmodified-since:

If-none-match: The file etag label stored in the local cache does not match the server

If-match

Security-related request header:

Authorication: Authentication data that the client submits to the server, such as account number and password

Cookie: Client sends to server-side ID

Cookie2

Proxy Request Header:

Proxy-authorization: Authenticating to a proxy server

Response Header

Age: Duration of response

Server: Indicates to the client the name and version of the servers program

Negotiation header: Used when a resource has multiple and presentation methods

Accept-ranges: The types of scopes that the server can accept for the current resource

Vary: The first list, the server will pick the most appropriate version according to the contents of the list sent to the client

Security-related response header

Set-cookie: Server-side token issued by a client on first request

Set-cookie2:

Www-authenication: Ask the client for an account and password

Entity Header        

Location: New Locations for resources

Allow: A request method that allows the use of this resource

Content Header:

Contern-encoding

Contern-language

The length of the contern-length entity

Contern-type Object Types for entities

Contern-range where the entity is actually located

Contern-location

Cache Header:

ETag: Extended label for entity

Expires: Entity Expiration label

Last-modified: Last Modified time

Extension header

Second, Curl command

Curl is a file transfer tool that works in command-line mode based on URL syntax, which supports protocols such as FTP, FTPS, HTTP, HTTPS, GOPHER, TELNET, DICT, file, and LDAP. Curl supports HTTPS authentication, and supports HTTP post, put and other methods, FTP upload, Kerberos authentication, HTTP upload, proxy server, cookies, username/password Authentication, download file breakpoint continuation, upload file breakpoint continuation,, HTTP proxy Server pipeline (proxy tunneling), even it supports IPV6, SOCKS5 proxy server, upload files via HTTP proxy server to FTP server and so on, the function is very powerful.

common options for Curl :

Grammar:

curl [Options] [URL ...]

-a/--user-agent <string> set user agent to send to server, that is, tell the server browser type

-basic using HTTP Basic authentication

--tcp-nodelay using the Tcp_nodelay option

-e/--referer <URL> Source URL, jump over the URL

--cacert <file> Specify CA certificate (SSL)

--compressed requirements Return is a compressed situation, if the file itself is a compressed file, you can download to the local

-h/--header <line> Custom header information to the server

-i/--head only the response message header information is displayed

--limit-rate <rate> Set Transfer speed

-u/--user <user[:p assword]> setting up the user and password for the server

-0/--http1.0 Using HTTP 1.0

Another tool: ELinks

ELinks [OPTION] ... [URL] ...

-dump: does not enter interactive mode, but directly outputs the contents of the URL to standard output

Three, Mod_deflate module

Use the Mod_deflate module to compress the page to optimize the transfer speed, can be written as a line, you can write multiple lines, the default is gzip

Applicable scenarios:

(1) Save bandwidth, additional CPU consumption, may be some older browsers do not support

(2) Compress resources that are suitable for compression, such as text files

setoutputfilter deflate# mod_deflate configuration # restrict compression  To these mime typesaddoutputfilterbytype deflate text/plainaddoutputfilterbytype  deflate text/htmladdoutputfilterbytype deflate application/xhtml+xmladdoutputfilterbytype  DEFLATE text/xmlAddOutputFilterByType DEFLATE application/xmlAddOutputFilterByType  deflate application/x-javascriptaddoutputfilterbytype deflate text/ javascriptaddoutputfilterbytype deflate text/css # level of compression  ( highest 9 - lowest 1) defaults to 6deflatecompressionlevel 9 # netscape 4.x  has some problems. Browsermatch ^mozilla/4 gzip-only-text/html # netscape 4.06-4.08 have some  more problemsbrowsermatch ^mozilla/4\.0[678] no-gzip # msie masquerades  as netscape,  but it is finebrowsermatch \bmsi[e] !no-gzip !gzip-only-text/html 

Web:3, httpd message Syntax format