Get size without authenticating?

Ze'ev G.

Can I get the size of a file via a CURL command given only a link without authenticating?

E.g.,

https://www.dropbox.com/s/uf12345szlap449/Files.mp4?dl=0

Greg-DB

Shared links like this (generally) don't require you to authenticate to access the content, so you can get the content and check the length. For example, using this link:

https://www.dropbox.com/s/vv7us05r9z46lwt/hello_world.txt?dl=0

We can ask for the raw file content by modifying the parameters as shown here:

https://www.dropbox.com/help/201

This gives us this version of the link:

https://www.dropbox.com/s/vv7us05r9z46lwt/hello_world.txt?raw=1

We can then access the content programmatically, e.g., using curl:

curl -L https://www.dropbox.com/s/vv7us05r9z46lwt/hello_world.txt?raw=1

(The -L is necessary to follow redirects.)

The response contains the length in the "Content-Length" header, e.g.:

Content-Length: 14

Alternatively, you can check the length of the returned file yourself.

Or, here's a more advanced method, using the Python requests library, to get the Content-Length without downloading the file, by using a HEAD request:

import requests

url = "https://www.dropbox.com/s/vv7us05r9z46lwt/hello_world.txt?raw=1"

redirected_url = requests.head(url).headers['location']

content_length = requests.head(redirected_url).headers['Content-Length']

print content_length

(Just don't re-use redirected_url. Always get a new one from the original link.)