## login
> In the movie _TRON: Legacy_, Linux is rebranded "SolarOS" in reference to [Solaris](<https://en.wikipedia.org/wiki/Solaris_(operating_system)>), another Unix OS
---
Start the VM to boot the previously installed Debian system.
Do the following for both a user and the [superuser ](https://en.wikipedia.org/wiki/Superuser ) (`root`) :
- Login in the console
- Clear the console using the keyboard shortcut
- Change the password to this : `michelle`
- Show the command history using five keystrokes or less (using autocompletion)
- Log out using the keyboard shortcut
### Just numbers
Login as [`root` ](https://en.wikipedia.org/wiki/Superuser ) on the third [Linux console ](https://en.wikipedia.org/wiki/Linux_console ).
Check the Internet connectivity with the command `ping google.com` .
After a few hops, interrupt the program with : < kbd > Ctrl< / kbd > + < kbd > C< / kbd > .
Behind every name in a computer system there is a number (ID, index, address, etc) :
- User identifier
- `root` → `0`
- `student` → `1000`
- IP address
- google.com → 216.58.214.14 (quad-dotted notation) → `3627734542`
- tencent.com → 117.169.101.44 (quad-dotted notation) → `1974035756`
- File inode
- `/etc/fstab` → `44696029`
- `.profile` → `59639363`
- Port
- `HTTP` → `80`
- `HTTPS` → `443`
- Process identifier
- `cron` → `254`
Names exist because they are human readable, but behind the scenes they are converted into numbers, unique in their namespace :
- A domain name can have several IP addresses, but an IP address can only identify one domain name
- Several processes may have the same name, but a PID identifies a single process
Find the commands to get :
- the inode of a specific file
- the current user ID
- the PID of a program, for example `bash`
