Anyone who has done Socket programming in HTTP request style knows that when we design a communication protocol, the "message header/message body" separation method is very commonly used. The message header tells the other party what the message is for, and the message body Tell the other person what to do.
When the browser requests services from the web server, errors may occur. It is possible to return the following series of status messages:
1xx: Message
Message: | describe: |
---|---|
100 Continue | The server receives only part of the request, but once the server does not reject the request, the client should continue to send the remaining requests. |
101 Switching Protocols | Server conversion protocol: The server will comply with the client's request and convert to another protocol. |
2xx: Success
Message: | describe: |
---|---|
200 OK | Request successful (followed by response documents to GET and POST requests.) |
201 Created | The request is created and new resources are created. |
202 Accepted | The request for processing has been accepted, but processing is not completed. |
203 Non-authoritative Information | The document has been returned normally, but some response headers may be incorrect because a copy of the document was used. |
204 No Content | No new documents. The browser should continue to display the original document. This status code is useful if the user refreshes the page regularly and the servlet can determine that the user's document is current enough. |
205 Reset Content | No new documents. But the browser should reset what it displays. Used to force the browser to clear form input content. |
206 Partial Content | The client sent a GET request with a Range header and the server completed it. |
3xx: Redirect
Message: | describe: |
---|---|
300 Multiple Choices | Multiple selections. Linked list. Users can select a link to reach their destination. A maximum of five addresses are allowed. |
301 Moved Permanently | The requested page has been moved to the new url. |
302 Found | The requested page has been temporarily moved to the new URL. |
303 See Other | The requested page can be found under another URL. |
304 Not Modified | The document was not modified as expected. The client has a buffered document and makes a conditional request (usually by providing an If-Modified-Since header to indicate that the client only wants documents that are newer than the specified date). The server tells the client that the original buffered document can continue to be used. |
305 Use Proxy | Documents requested by the client should be retrieved through the proxy server specified by the Location header. |
306 Unused | This code was used in the previous version. It is no longer in use, but the code is still retained. |
307 Temporary Redirect | The requested page has been temporarily moved to the new URL. |
4xx: Client error
Message: | describe: |
---|---|
400 Bad Request | The server failed to understand the request. |
401 Unauthorized | The requested page requires a username and password. |
402 Payment Required | This code is not available yet. |
403 Forbidden | Access to the requested page is prohibited. |
404 Not Found | The server cannot find the requested page. |
405 Method Not Allowed | The method specified in the request is not allowed. |
406 Not Acceptable | The response generated by the server was not acceptable to the client. |
407 Proxy Authentication Required | Users must first authenticate using a proxy server so that the request will be processed. |
408 Request Timeout | The request exceeded the server's waiting time. |
409 Conflict | The request could not be completed due to a conflict. |
410 Gone | The requested page is unavailable. |
411 Length Required | "Content-Length" is not defined. Without this content, the server will not accept the request. |
412 Precondition Failed | The precondition in the request was evaluated as failed by the server. |
413 Request Entity Too Large | The server will not accept the request because the requested entity is too large. |
414 Request-url Too Long | The server will not accept the request because the url is too long. This happens when a POST request is converted into a GET request with very long query information. |
415 Unsupported Media Type | The server will not accept the request because the media type is not supported. |
416 | The server cannot satisfy the Range header specified by the client in the request. |
417 Expectation Failed |
5xx: Server Error
Message: | describe: |
---|---|
500 Internal Server Error | The request is not completed. The server encountered an unpredictable situation. |
501 Not Implemented | The request is not completed. The server does not support the requested functionality. |
502 Bad Gateway | The request is not completed. The server received an invalid response from the upstream server. |
503 Service Unavailable | The request is not completed. The server is temporarily overloaded or down. |
504 Gateway Timeout | Gateway timeout. |
505 HTTP Version Not Supported | The server does not support the HTTP protocol version specified in the request. |
Related recommendations:
HTTP preliminary annotation-Yitoem
PHP Modify HTTP header-Modify HTTP Headers
The above is the detailed content of How to get HTTP status messages. For more information, please follow other related articles on the PHP Chinese website!

Node.js excels at efficient I/O, largely thanks to streams. Streams process data incrementally, avoiding memory overload—ideal for large files, network tasks, and real-time applications. Combining streams with TypeScript's type safety creates a powe

The differences in performance and efficiency between Python and JavaScript are mainly reflected in: 1) As an interpreted language, Python runs slowly but has high development efficiency and is suitable for rapid prototype development; 2) JavaScript is limited to single thread in the browser, but multi-threading and asynchronous I/O can be used to improve performance in Node.js, and both have advantages in actual projects.

JavaScript originated in 1995 and was created by Brandon Ike, and realized the language into C. 1.C language provides high performance and system-level programming capabilities for JavaScript. 2. JavaScript's memory management and performance optimization rely on C language. 3. The cross-platform feature of C language helps JavaScript run efficiently on different operating systems.

JavaScript runs in browsers and Node.js environments and relies on the JavaScript engine to parse and execute code. 1) Generate abstract syntax tree (AST) in the parsing stage; 2) convert AST into bytecode or machine code in the compilation stage; 3) execute the compiled code in the execution stage.

The future trends of Python and JavaScript include: 1. Python will consolidate its position in the fields of scientific computing and AI, 2. JavaScript will promote the development of web technology, 3. Cross-platform development will become a hot topic, and 4. Performance optimization will be the focus. Both will continue to expand application scenarios in their respective fields and make more breakthroughs in performance.

Both Python and JavaScript's choices in development environments are important. 1) Python's development environment includes PyCharm, JupyterNotebook and Anaconda, which are suitable for data science and rapid prototyping. 2) The development environment of JavaScript includes Node.js, VSCode and Webpack, which are suitable for front-end and back-end development. Choosing the right tools according to project needs can improve development efficiency and project success rate.

Yes, the engine core of JavaScript is written in C. 1) The C language provides efficient performance and underlying control, which is suitable for the development of JavaScript engine. 2) Taking the V8 engine as an example, its core is written in C, combining the efficiency and object-oriented characteristics of C. 3) The working principle of the JavaScript engine includes parsing, compiling and execution, and the C language plays a key role in these processes.

JavaScript is at the heart of modern websites because it enhances the interactivity and dynamicity of web pages. 1) It allows to change content without refreshing the page, 2) manipulate web pages through DOMAPI, 3) support complex interactive effects such as animation and drag-and-drop, 4) optimize performance and best practices to improve user experience.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

MantisBT
Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Notepad++7.3.1
Easy-to-use and free code editor

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software
