html5 - 为什么没有后缀名的图片可以在网页中显示？

Question

http://cdn.aixifan.com/dotnet...
这个图片在网页上是没有后缀名的，下载下来是gif，请问是怎么实现的？

Answer 1

is shown below because of the Content-Type: image/gif header.

$ curl -I -X GET http://cdn.aixifan.com/dotnet/artemis/u/cms/www/201512/18171819tvawkism.gif?imageView2/1/w/40/h/40
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0 44199    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0HTTP/1.1 200 OK
Date: Wed, 30 Nov 2016 14:49:22 GMT
Content-Type: image/gif
Content-Length: 44199
Connection: keep-alive
Expires: Wed, 24 May 2017 04:00:09 GMT
Server: nginx/1.8.0
Last-Modified: Fri, 18 Dec 2015 09:16:24 GMT
ETag: "5673cee8-aca7"
Cache-Control: max-age=20736000
Accept-Ranges: bytes
X-Ser: BC81_dx-lt-hebei-shijiazhuang-2-cache-1, BC79_dx-beijing-beijing-4-cache-1, BC250_KR-seoul-seoul-1-cache-2, BC136_SG-singapore-singapore-1-cache-1

Moreover, the reason why the pictures you usually see are displayed as pictures by the browser is usually because the web server such as apache or nginx outputs the MIME-Type for you, or because it is written in <img src="xxx">. Please check the nginx configuration: include /etc/nginx/mime.types; Among them, /etc/nginx/mime.types this file records the association between most common file extensions and MIME types. If the file suffix requested by the client is in this file, nginx will output the corresponding content-type header for you.

If your doubts are answered, please accept it

Answer 2

? Isn’t the previous one .gif? The previous gif already represents the suffix of the file
? The following content is called passing parameters

Besides, just output the header of Content-Type: image/gif Content-Type: image/jpg, even if the suffix is ​​php,
for example: https://www.load-page.com/base/attachment?id=777

Answer 3

See?

And even if there is no suffix, the gateway server (apache/nginx) can help you find the image. In Linux, files are not distinguished by file name suffixes.