How to turn off ob series functions in PHP

In PHP, use the ob function to control output buffering to achieve better performance and user experience. The ob function provides many features, including output caching, output redirection, compression, and more. But in some cases, we need to close ob manually. This article will introduce how to close ob in PHP.

1. What is ob?

In PHP, the ob function is the core of output buffer control. It opens the buffer through the ob_start function so that the output content will not be sent directly to the browser, but will be stored in the buffer first. You can use the ob_flush function to send the contents of the buffer to the browser and clear the buffer at the same time. You can also use the ob_end_flush function to close the buffer and clear its contents after sending its contents, and the ob_clean function to clear the buffer without closing it.

2. Why do you need to close ob?

By default, ob is turned on, but in some cases, we need to manually turn off ob, such as:

1. For some dynamically generated pages, it may be caused by viewing The content does not change much or the content is relatively simple, and it is impossible to reduce network bandwidth consumption through the browser's caching mechanism. At this time, you can use ob cache to store the page content in the cache. After loading the complete page for the first time, refresh the changed content through ajax technology, which can reduce bandwidth consumption and improve page response speed.
2. When using ob caching technology, you can avoid repeated operations such as output, redirection or compression in the code, making the code more maintainable.
3. In some applications, you may need to save the output results to a file or memory. At this time, you can enable ob to perform the operation and close the ob cache after completing the operation. This can ensure that the results can be accurately saved to the specified location. Location.

3. How to close ob?

To close ob in PHP, you can use the ob_end_clean or ob_end_flush method. Both methods can close the output buffer and clear all data in the buffer. The only difference is that ob_end_clean does not output the contents of the buffer, while ob_end_flush outputs all the contents of the buffer to the browser.

The sample code is as follows:

//开启输出缓冲
ob_start();
//输出内容
echo "Hello World!";
//关闭输出缓冲并打印内容到浏览器
ob_end_flush();

Use the ob_get_contents method to get the contents of the buffer and save it to a file.

//开启输出缓冲
ob_start();
//输出内容
echo "Hello World!";
//获取缓冲区域的数据
$contents = ob_get_contents();
//关闭输出缓冲
ob_end_clean();
//将内容保存到文件中
file_put_contents('file.txt', $contents);

4. Summary

The ob function is a very practical tool in PHP. Through the ob buffer, we can better control the output and achieve the effect of optimizing performance. In some cases, we need to manually close ob to avoid occupying too many system resources and improve overall program performance. To close ob, you can use the ob_end_clean or ob_end_flush method. Both are used for different processing methods of the buffer. The specific use depends on the actual needs.

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