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The extension doesn't necessarily have to just say what the file is, but it can also say how it should be used. This is done with the .apk extension. apks are z

The extension doesn't necessarily have to just say what the file is, but it can also say how it should be used. This is done with the .apk extension. apks are zip files, the but apk extension says it should be loaded as an application in Android. It also isn't only useful for computers. It helps people to know what they're getting into when they open a file. An mp4 with a gifv extension makes sense to me. It says "I'll be loaded without audio and will play in a loop".

cheald 12y ago
Extensions in HTTP mean jack-all. Content-types/MIME types are what actually tell you how the file should be treated. Imgur is serving text/html in their ".gifv" files. If you tried to load a gifv in a <video> tag it would crash and burn on you because...it's serving you an HTML document with a text/html MIME type. Imgur will happily serve you GIFs and JPEGs with incorrect extensions - for example, if you get this image with a .gif extension, it's going to serve you a JPEG, and it's going to be decoded by libjpeg. The extension doesn't provide any useful information to the client about what to do with the data. $ wget http://i.imgur.com/hDYj7E7.gif --2014-10-09 14:00:53-- http://i.imgur.com/hDYj7E7.gif Resolving i.imgur.com (i.imgur.com)... 23.235.47.193 Connecting to i.imgur.com (i.imgur.com)|23.235.47.193|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 158352 (155K) [image/jpeg] Saving to: ‘hDYj7E7.gif’ 2014-10-09 14:00:53 (865 KB/s) - ‘hDYj7E7.gif’ saved [158352/158352] $ identify hDYj7E7.gif hDYj7E7.gif JPEG 577x1024 577x1024+0+0 8-bit DirectClass 158KB 0.000u 0:00.030
- jonny_eh 12y ago
  > Extensions mean jack-all …to browsers.
  - cheald 12y ago
    You're right. I edited my post to clarify with "in HTTP". Though I'll argue that it's not really relevant in this context of this particular subject, since ".gifv" only makes sense in a browser/HTTP context. Everywhere else it's just HTML.
tripzilch 12y ago
Yes, and the same goes for .jar extensions.

cheald 12y ago

Extensions in HTTP mean jack-all. Content-types/MIME types are what actually tell you how the file should be treated. Imgur is serving text/html in their ".gifv" files. If you tried to load a gifv in a <video> tag it would crash and burn on you because...it's serving you an HTML document with a text/html MIME type. Imgur will happily serve you GIFs and JPEGs with incorrect extensions - for example, if you get this image with a .gif extension, it's going to serve you a JPEG, and it's going to be decoded by libjpeg. The extension doesn't provide any useful information to the client about what to do with the data. $ wget http://i.imgur.com/hDYj7E7.gif --2014-10-09 14:00:53-- http://i.imgur.com/hDYj7E7.gif Resolving i.imgur.com (i.imgur.com)... 23.235.47.193 Connecting to i.imgur.com (i.imgur.com)|23.235.47.193|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 158352 (155K) [image/jpeg] Saving to: ‘hDYj7E7.gif’ 2014-10-09 14:00:53 (865 KB/s) - ‘hDYj7E7.gif’ saved [158352/158352] $ identify hDYj7E7.gif hDYj7E7.gif JPEG 577x1024 577x1024+0+0 8-bit DirectClass 158KB 0.000u 0:00.030

jonny_eh 12y ago
> Extensions mean jack-all …to browsers.
- cheald 12y ago
  You're right. I edited my post to clarify with "in HTTP". Though I'll argue that it's not really relevant in this context of this particular subject, since ".gifv" only makes sense in a browser/HTTP context. Everywhere else it's just HTML.

tripzilch 12y ago

Yes, and the same goes for .jar extensions.