mirror of https://github.com/01-edu/public.git
53 lines
1.8 KiB
Markdown
53 lines
1.8 KiB
Markdown
## login
|
|
|
|
![TRON: Legacy](tron.jpg)
|
|
|
|
> 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`
|