Mac El Capitan: Camera Not Working

Since updated to El Capitan, many things went wrong. Last time screen was blurry, now camera does not work. The symptom is camera is not recognized in FaceTime, in QuickTime Video recording, and in any video recorder app. So a little search online gives the solution:

The Way to Update A Small RAM VPS

So I have a VPS with about 700MB RAM but the available is < 100MB. Today when I do yum update I got the error saying xxxx: [Errno 5] [Errno 12] Cannot allocate memory So I solved this by update everything one by one using the following command:

Categorized as inHacking

Brief Review about Protocol Security

There are many application-level protocols in networks. There are File Transfer Protocols like ftp, scp, and sftp. There are Mail Protocols like smtp, pop, and imap. There are Web Protocols like http 1.0, 1.1, and 2.0. And there are many more. But they are not that secure.