How can I prompt if the size of the file uploaded by php exceeds the limit of post_max_size?

When php processes file uploads that exceed the post_max_size limit, how does one prompt a problem found during the test of a recent project? when my uploaded file exceeds the post_max_size limit, the page does not respond, only the post_max_size value can be passively Retrieved. after the value of post_max_size is modified, it is found that the uploaded file is larger than the size limit of the post_max_size file uploaded by upload php. how can I prompt
A problem found during the test of the latest project is that when the size of the uploaded file exceeds the limit of post_max_size, the page does not respond and can only passively modify the value of post_max_size, after modifying the value of post_max_size, we found that the size of the uploaded file is greater than the size set by upload_max_filesize. The size of the file obtained is 0.

What I want now is to give the user a prompt in advance that the file to be uploaded is too large to be uploaded ????


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Ini_get () can obtain some parameters in php. ini. Compare $ _ FILES ["file"] ["size"] with upload_max_filesize.

Alternatively, you can use the error code $ _ FILES ["file"] ["error. If the value is greater than 0, the upload is incorrect. If the value is 1, it indicates that the size of upload_max_filesize is exceeded.
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Yes! It's no longer a php task to use js.
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Customer segment control.
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Discussion

Reference:

Customer segment control.

I don't understand how the client controls it? The fileSize method I found online using js is not easy to use. can you elaborate!

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PHP can also be controlled, but requires a verification page and then uses the second floor method.