Shareable soundcloud links are shrinked links, who look like this :
=> on.soundcloud.com/XXXXX => code 302 :redirect => soundcloud.com/artist/track),
and this can redirect to public tracks as well as private ones too... bruteforce time.

the script catchs the redirect, and uses a regex to find if the full link contains a private token (public ones does not have any)
and if the regex matches, then a private track has been found.

actually, because of the regex-only filter theres some false-positives:
-old private tracks who kept their same shareable link, which are public now, will stiff have a private token on the link;
-sometimes deleted tracks does match.

this is easy to fix tho, i just need to do it :')