# Linux

- [Distro](#distro)
- [Graphical Environment](#graphical-environment)
  - [Display Managers](#display-managers)
    - [cli - utils](#cli---utils)
  - [Graphical Applications](#graphical-applications)
    - [Gnome Files/Nautilus](#gnome-filesnautilus)
- [Commands and Utilities](#commands-and-utilities)
  - [Navigation and File Management](#navigation-and-file-management)
  - [Archiving and Compression](#archiving-and-compression)
    - [tar](#tar)
  - [Users, Groups, and File permissions](#users-groups-and-file-permissions)
  - [loginctl](#loginctl)
    - [terminate-user](#terminate-user)
  - [Network Configuration](#network-configuration)
    - [hostname / hostnamectl](#hostname--hostnamectl)
    - [static ip](#static-ip)
  - [System info](#system-info)
  - [System Monitoring Utilities](#system-monitoring-utilities)
    - [btop](#btop)
    - [memory usage by user](#memory-usage-by-user)
  - [Storage](#storage)
    - [Disk Space and Used](#disk-space-and-used)
    - [Physical Disks and Partition](#physical-disks-and-partition)
    - [hdparm](#hdparm)
    - [smartctl](#smartctl)
  - [Network Storage](#network-storage)
    - [smb](#smb)
    - [gio](#gio)
  - [CLI Diagnostics and System Topology](#cli-diagnostics-and-system-topology)
    - [lspci](#lspci)

## Distro

- [Debian](./docs/distros/debian.md)
- [Fedora](./docs/distros/fedora.md)
- [Proxmox pve](https://git.limbosolutions.com/kb/proxmox)

## Graphical Environment

### Display Managers

A display manager is a graphical login manager that:

- starts the Xorg or Wayland display server
- shows a login screen (greeter)
- authenticates the user
- launches the user’s session (desktop environment or window manager)

Examples:

- [LightDM (lightweight and flexible)](./docs/display-managers/lightdm.md)
- [GDM (GNOME Display Manager)](./docs/desktop-environments/gnome.md)
- [SDDM](./docs/display-managers/sddm.md) - Used by [KDE](./docs/desktop-environments/kde.md)
- LXDM (used by LXDE)
- [matchbox-window-manager](./docs/display-managers/matchbox‑wm.md)

#### cli - utils

check which display manager is currently running on your system.

**Debian:**

``` bash
systemctl status display-manager
```

### Graphical Applications

#### Gnome Files/Nautilus

<https://www.maketecheasier.com/useful-nautlius-tweaks-linux/>

## Commands and Utilities

### Navigation and File Management

📁 List  information  about the FILEs (the current directory by default).

```bash
#order by date 
ls -t

#order by date reverse
ls -r

# list all
ls -lah
```

### Archiving and Compression

#### tar

**📦 tar** is a command-line utility in Unix/Linux used to archive multiple files into a single file, often for backup, compression, or distribution. The name stands for “tape archive”, originally designed for writing data to magnetic tape.

**Flags:**

- -c  Create a new archive
- -v  Verbose — show progress while archiving
- -p  Preserve permissions — keeps original file permissions
- -z  Compress using gzip
- -f  File name — expects a filename right after this flag
- -I  compressor  
- -p  preserve file permissions

```bash
tar -cvf --exclude='.cache' --exclude='Cache'  --exclude='.cache' --exclude='.tmp' --exclude='tmp' /tmp/filename.tar.gz \
$source_path_to_tar


#(Parallel Implementation of Gzip) to to create a fast, compressed archive
tar -I pigz -cvf - /fileserver/media/music/*

# splits the output into 8 GB chunks,
tar -I pigz -cvf - /sourcefolder/* | split --bytes=8GB - /tmp/file.tar.gz
```## Visual Linux


```bash
tar -cvpzf "/vault/.backups/devices/homeserver/tar/backup_$(date +"%Y%m%d%H%M%S").tar.gz \
--exclude=/proc \
--exclude=/tmp \
--exclude=/mnt \
--exclude=/dev \
--exclude=/sys \
--exclude=/run \
--exclude=/media \
--one-file-system \
/
```

### Users, Groups, and File permissions

```bash
#create
useradd USERNAME
# create with home directory
useradd -m USERNAME

#remove
userdel USERNAME
#useradd -r USERNAME
passwd
passwd USERNAME
groups
groupadd GROUPNAME
groups USERNAME
usermod -a -G GROUPNAME USERNAME

```

### loginctl

*command belongs to systemd‑logind.*

#### terminate-user

terminate-user <username> Terminates all processes and sessions belonging to the specified user. This works on any system using systemd — including headless servers with no graphical environment. On headless systems, it closes SSH/TTY sessions and kills all user‑owned processes. On graphical systems, it also terminates Xorg/Wayland sessions and window managers.

``` bash
loginctl terminate-user <username>
```

### Network Configuration

#### hostname / hostnamectl

``` bash

#get hostname
hostname

#set hostname
hostnamectl

sudo nano /etc/hostname
#alterar o nome
sudo nano /etc/hosts
#alterar o nome
Static IP
A configuração para um ip estático poderá ser um pouco diferente de distribuição para distribuição mas a lógica é similar
```

#### static ip

Debian
sudo nano /etc/network/interfaces
Exemplo de configuração

``` bash
# neste exemplo de configuração a place de rede tem o nome enxd0374555c1f8 

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface

allow-hotplug enxd0374555c1f8
iface enxd0374555c1f8 inet static
  address 192.168.0.2
  netmask 255.255.255.0
  gateway 192.168.0.1
  dns-nameservers 89.207.128.252 89.207.130.252
Reiniciar configuração sem reboot de computador
```

``` bash
# restart configuration servicce
sudo /etc/init.d/networking restart
```

### System info

```bash
# get distribution
cat /etc/os-release

# get kernel version
uname -a
```

### System Monitoring Utilities

#### btop

**Install Debian & Ubuntu:**

```bash
apt update && apt install btop -y
```

#### memory usage by user

``` bash
 ps -eo user,rss --no-headers \
  | awk '{mem[$1]+=$2} END {for (u in mem) printf "%-15s %.1f MB\n", u, mem[u]/1024}'
```

### Storage

#### Disk Space and Used

``` bash
df -h
```

#### Physical Disks and Partition

**List physical disks and partition size:**

``` bash
lsblk
```

**Get Partition id:**

``` bash
blkid /dev/sdX
```

##### Partition Manager

``` bash
fdisk /dev/sdX
```

[check](./docs/file-systems.md) for file systems.

#### hdparm

hdparm is a powerful command-line utility in Linux used to view and configure low-level parameters of SATA, IDE, and some USB hard drives. It’s commonly used for performance tuning, diagnostics, and power management.

``` bash
sudo apt install hdparm
sudo hdparm -Tt /dev/sdc
```

#### smartctl

smartctl is a command-line utility used to monitor and manage the health of storage devices like HDDs and SSDs using S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology).

Here’s a deeper look at what smartctl does and why it’s useful:

```bash
#check smart status
smartctl -a /dev/sdX
```

``` bash
df
df -h
du -h --max-depth=1

```

### Network Storage

#### smb

smb share

Create credentials file

``` bash
#/home/mf/.credentials/smb:mf@nas.lan
username=shareuser
password=sharepassword
domain=domain_or_workgroupname
```

Secure credentials file permission

``` bash
chmod 0600 /home/mf/.credentials/smb:mf@nas.lan
```

Add line

``` bash
#/etc/fstab
//nas.lan/homes /mnt/smb-share:mf@nas.lan,share=homes cifs credentials=/home/mf/.credentials/smb:mf@nas.lan,uid=1000,gid=1000,nofail 0 0
```

#### gio

**mount samba share:**

```bash
#/home/username/.credentials
#username
#SAMBA
#password
gio mount smb://server/share < /home/username/.credentials
```

**unmount:**

```bash
gio mount -u smb://server/share
```


### CLI Diagnostics and System Topology

#### lspci

Displays information about each PCI bus on your system. This includes information about the devices connected to the PCI subsystem.

lspci [options]

| Option | Description |
| -------- | ------------- |
| -v     | Verbose     |

``` bash
lspci -v
```