How to determine if a given URL link is a video or image?

Question

I\'m trying to take a given URL entered by user and determine if the URL is pointing to a image or a video.

Example use case:

When a user paste in the URL o

Answer 1

I suggest using curl with a range header to allow you to inspect the file type itself.

curl -s -v -r0-499 -o test  http://stackoverflow.com/content/img/so/logo.png
* About to connect() to stackoverflow.com port 80 (#0)
*   Trying 69.59.196.211... connected
* Connected to stackoverflow.com (69.59.196.211) port 80 (#0)
> GET /content/img/so/logo.png HTTP/1.1
> Range: bytes=0-499
> User-Agent: curl/7.19.4 (i386-apple-darwin9.6.0) libcurl/7.19.4 zlib/1.2.3
> Host: stackoverflow.com
> Accept: */*
> 
< HTTP/1.1 206 Partial Content
< Cache-Control: max-age=604800
< Content-Type: image/png
< Content-Range: bytes 0-499/3438
< Last-Modified: Fri, 05 Jun 2009 06:52:35 GMT
< Accept-Ranges: bytes
< ETag: "25dd4b35aae5c91:0"
< Server: Microsoft-IIS/7.0
< Date: Fri, 19 Jun 2009 19:39:43 GMT
< Content-Length: 500
< 
{ [data not shown]
* Connection #0 to host stackoverflow.com left intact
* Closing connection #0

Then execute:

$ file test
test: PNG image data, 250 x 61, 8-bit colormap, non-interlaced

Now you know the mime type: image/png, the file size 3438 bytes, and the file is a 250 x 61 color PNG image.