dot com links don't work

[ghost]

manu:Downloads/ $ youtube-dl https://www.youtube.com/watch?v=I56W7-j1Y4I
zsh: no matches found: https://www.youtube.com/watch?v=I56W7-j1Y4I
manu:Downloads/ $ youtube-dl https://youtu.be/I56W7-j1Y4I            [22:54:48]
[youtube] I56W7-j1Y4I: Downloading webpage
[youtube] I56W7-j1Y4I: Downloading video info webpage
[youtube] I56W7-j1Y4I: Extracting video information
[youtube] I56W7-j1Y4I: Downloading DASH manifest
[youtube] I56W7-j1Y4I: Downloading DASH manifest
...

[csuttles]

What version are you using? I just installed via pip and was able to pull the same video that failed for you without a problem:

✔ ~
13:03 $ pip install youtube-dl
Collecting youtube-dl
  Downloading youtube_dl-2015.10.06.2-py2.py3-none-any.whl (1.1MB)
    100% |████████████████████████████████| 1.1MB 284kB/s
Installing collected packages: youtube-dl
Successfully installed youtube-dl-2015.10.6.2
...
✔ ~/tmp
14:19 $ youtube-dl https://www.youtube.com/watch?v=I56W7-j1Y4I
[youtube] I56W7-j1Y4I: Downloading webpage
[youtube] I56W7-j1Y4I: Downloading video info webpage
[youtube] I56W7-j1Y4I: Extracting video information
[youtube] I56W7-j1Y4I: Downloading DASH manifest
[youtube] I56W7-j1Y4I: Downloading DASH manifest

[ghost]

Which shell do you use? Maybe it is an issue with zsh. I'm using 2015.08.28 👴

[csuttles]

I'm using bash. I saw your error string and also thought it might be a shell issue.

Looks like it is probably just a shell/globbing thing actually:

zoidberg% youtube-dl https://www.youtube.com/watch?v=I56W7-j1Y4I
zsh: no matches found: https://www.youtube.com/watch?v=I56W7-j1Y4I
zoidberg% youtube-dl 'https://www.youtube.com/watch?v=I56W7-j1Y4I'
[youtube] I56W7-j1Y4I: Downloading webpage
[youtube] I56W7-j1Y4I: Downloading video info webpage
[youtube] I56W7-j1Y4I: Extracting video information
[youtube] I56W7-j1Y4I: Downloading DASH manifest
[youtube] I56W7-j1Y4I: Downloading DASH manifest
[download] Destination: Question - Is Computer Support Or Web Design A Better Career-I56W7-j1Y4I.mp4

[yan12125]

As @csuttles said, you need to enclose the URL in single or double quotes in some shells.