How does PHP accurately determine the extension of a remote file?

The HTTP response header is as follows:
Array
(
[0] = = http/1.1-OK

[1] = content-length:345942

[2] = Content-type:application/octet-stream

[3] = server:microsoft-iis/6.0

[4] = X-powered-by:asp.net

[5] = Date:sun, Dec 05:44:39 GMT

[6] = Connection:close

)

There is no extension in the file name, disorganized.

Reply to discussion (solution)

The file name is only used to identify the block of data stored in the media
In network communication, the file name is meaningless.

Since Content-type:application/octet-stream has declared that it is a flow
And the length of the content-length:345942 is not too big, you can first as a picture to analyze
All traffic is marked with a specific identifier, and the previous stage has been where someone sent code, and you can find

The file name is only used to identify the block of data stored in the media
In network communication, the file name is meaningless.

Since Content-type:application/octet-stream has declared that it is a flow
And the length of the content-length:345942 is not too big, you can first as a picture to analyze
All traffic is marked with a specific identifier, and the previous stage has been where someone sent code, and you can find

Content-type:application/octet-stream this corresponds to many types of files, not unique. Additionally this file is in RAR format. Not a picture.

The file name is only used to identify the block of data stored in the media
In network communication, the file name is meaningless.

Since Content-type:application/octet-stream has declared that it is a flow
And the length of the content-length:345942 is not too big, you can first as a picture to analyze
All traffic is marked with a specific identifier, and the previous stage has been where someone sent code, and you can find

Content-type:application/octet-stream this corresponds to many types of files, not unique. Additionally this file is in RAR format. Not a picture.

Find the answer, based on the file header is the most reliable
Http://www.yc-edu.org/PHPpeixun/1233.html

Just because the type is Application/octet-stream
That's why you need to identify yourself!
Their own identification will be based on the characteristics of the Knowledge base, common file types There are thousands of kinds of, you are willing to compare the one over again, I do not oppose
and the most common ones are about 10, and it's much quicker to check them out.

RAR file feature Word is rar
The feature word of the JPG file is JFIF
PNG file's feature word is PNG
....

Just because the type is Application/octet-stream
That's why you need to identify yourself!
Their own identification will be based on the characteristics of the Knowledge base, common file types There are thousands of kinds of, you are willing to compare the one over again, I do not oppose
and the most common ones are about 10, and it's much quicker to check them out.

RAR file feature Word is rar
The feature word of the JPG file is JFIF
PNG file's feature word is PNG
....

What do you mean by identifying yourself??

