The best command for this is who -a. This allows you to see everyone logged in and where. Here's what my who -a output looks like right now.
LOGIN tty1 2013-04-09 03:41 207 id=tty1
yaro ? :0 2013-04-09 03:41 ? 303
yaro + pts/0 2013-04-09 03:41 06:12 359 (:0)
yaro - pts/1 2013-04-09 03:41 . 550 (:0)
I suggest looking at the who manpage for more details.
the answer is Who
There are several commands depending on how much detail you want, and whether or not a certain package is installed on the system. The command 'who', 'w', 'users' will give varying degrees of information on who is logged in. The 'finger' command will also give some information but only if the finger software is installed.
You can see who is logged in with the "who" or "w" commands.
Background processes are tied to a terminal's job control, while a daemon runs headless. When the terminal is killed or the user is logged out, the process dies. A daemon does not need the user to be logged in.
Only one user at a time can be logged into Windows 2000 Professional. Any number of users can be logged into a Terminal Server; it isn't unusual for a large business to have 100,000 users logged into one server.
There are a series of commands, depending on what and how much information you want on logged in users. The commands are: who w users finger (if installed)
Short answer: Yes
Yes, YouTube will save your specific computer history by using "cookies". Although, if you're not logged in to YouTube, the video view history and video recommendations, etc. won't be tracked on your specific YouTube account because your account was not logged in.
B) who
Use 'man -k' with the keyword, or apropos
I think in all cases, Yes. However, how to log out depends where you logged in. If you logged in through Safari, then yes - simply go back to Safari, and at the bottom of their mobile site, you should see "Log out".If you logged in through a specific Yahoo application, look in the "settings" section, at the bottom, for that specific app - or inside the app itself.
"pts0" is a pseudo terminal. It would most commonly be used to bring up a terminal emulator, such as xterm or Konsole, in the GUI. If you have logged in or assumed root privileges in such a window, that would account for root being on pts0. If you logged into a tty, that would account for the other root. Some daemons may potentially also run as root during startup, creating the root login on, say, tty3.
Yes. Just make sure you have the path to the programs in your PATH environment variable.