How does PHP Upload files?

Is it uploaded to the temporary directory, and then the files in the temporary directory are written to the specified directory as needed? But before writing a directory, Should I read it into the memory first? If it is read into the memory. Isn't it because the server has crashed after reading a few large files? Is it uploaded to the temporary directory, and then the files in the temporary directory are written to the specified directory as needed? But before writing a directory, Should I read it into the memory first? If it is read into the memory. Isn't it because the server has crashed after reading a few large files?

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Is it uploaded to the temporary directory, and then the files in the temporary directory are written to the specified directory as needed? But before writing a directory, Should I read it into the memory first? If it is read into the memory. Isn't it because the server has crashed after reading a few large files?

First, let's take a look at upload_max_filesize, post_max_size, and memory_limit in php. ini.
The server will not crash, but the upload will fail.

The temporary directory is usually the/tmp directory.