How to
Topics
Download files from the cloud
Installing wget
sudo apt install wget
Download a single file
wget https://wordpress.org/latest.zip
Save the downloaded file under a different name
To save the downloaded file under a different name, pass the -O
option followed by the chosen name.
wget -O latest-wordpress.zip https://wordpress.org/latest.zip
How to download in the background mode with wget
To download in the background, use the option -b
. In the following example, we are downloading the OpenSuse iso file in the background.
wget -b https://download.opensuse.org/tumbleweed/iso/openSUSE-Tumbleweed-DVD-x86_64-Current.iso
Download all files from FTP
wget -r 'ftp://username:password@ip/directoryname'
Download / Upload Files
Single file from remote to local
scp remoteuser@remoteserver:/remote/folder/myfile.txt myfile.txt
Multiple files from local to remote
scp myfile.txt myfile2.txt remoteuser@remoteserver:/remote/folder/
All files from local to remote
scp * remoteuser@remoteserver:/remote/folder/
All files and folders recursively from local to remote
scp -r * remoteuser@remoteserver:/remote/folder/
References: Simplified Guide
DNS
Custom DNS
$ vim /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4
Custom DNS servers for /etc/resolv.conf
To define a custom DNS:
First, install
resolvconf
and follow the commands bellow
sudo apt install resolvconf -y
Put the nameservers from Google inside the file
/etc/resolvconf/resolv.conf.d/head
sudo sh -c "echo \"nameserver 8.8.8.8
nameserver 8.8.4.4\" >> /etc/resolvconf/resolv.conf.d/head"
sudo sh -c "echo \"nameserver 8.8.8.8
nameserver 8.8.4.4\" >> /etc/resolvconf/resolv.conf.d/base"
Update Resolvconf
sudo resolvconf -u
Restart the resolvconf service
sudo service resolvconf restart
Get current IP from the shell
remoteHost=$(dig +short myip.opendns.com @resolver1.opendns.com)
echo $remoteHost
Stream audio
sudo apt install -y pulseaudio pavucontrol
Alt + F2
and typepavucontrol
Select
Recording
tabChange to
Internal audio monitor
Search inside files recursively
grep -rli "my-name"
Display Usage in Megabytes and Gigabytes
df -h
Display a Specific File System
df –h /dev/sda2
Show size of folders
sudo du -shc /var/*
Empty trash
rm -rf ~/.local/share/Trash/*
Search and replace inside the file
sed -i 's/SEARCH_REGEX/REPLACEMENT/g' INPUTFILE
Network
Check network ports in use
sudo netstat -tlnp | grep 80
Check opened network ports of the server
nmap HOST
## Example
nmap google.com
nmap 55.1.22.5.68
Open network ports
# Openning 8080 port
sudo iptables -A INPUT -p tcp --dport 8080 -j ACCEPT
Open Firewall ports
To open ports on the firewall, using the iptables command is possible specifying the desired port. Using the example below, just replace port 8888 with the desired port.
$ iptables -I INPUT -p tcp --dport 8888 -j ACCEPT
$ iptables -t filter -I FORWARD -i eth2 -o etho -m multiport --dport 8888 -j ACCEPT
Logs
Show real-time logs from OS
tail -f /var/log/syslog
# Or you can use journalctl
# journalctl -f
Environment
Set Global environment
sudo sh -c "echo MY_GLOBAL_ENV_TO_MY_CURRENT_DIR=$(pwd)" >> /etc/environment"
Set local environment
env MY_GLOBAL_ENV_TO_MY_CURRENT_DIR=$(pwd)
Unset local environment
unset MY_GLOBAL_ENV_TO_MY_CURRENT_DIR
Startup
Show all service status
sudo service --status-all
Exec commands at startup
sudo vim /etc/init.d/rc.local
#!/bin/bash
#command1
#command2
exit 0;
sudo chmod ugo+x /etc/init.d/rc.local
update-rc.d rc.local defaults
PPA
Remove installed PPA repository
Use the "--remove" flag, similar to how the PPA was added:
sudo add-apt-repository --remove ppa:whatever/ppa
As a safer alternative, you can install "ppa-purge":
sudo apt-get install ppa-purge
And then remove the PPA, downgrading gracefully packages it provided to packages provided by official repositories:
sudo ppa-purge ppa:whatever/ppa
Note that this will uninstall packages provided by the PPA, but not those provided by the official repositories. If you want to remove them, you should tell it to apt:
sudo apt-get purge package_name
You can also remove PPAs by deleting the .list files from /etc/apt/sources.list.d
directory.
Last but not least, you can also disable or remove PPAs from the "Software Sources" section in Ubuntu Settings with a few clicks of your mouse (no terminal needed).
Execute "add-apt-repository" without press enter
# Example
sudo add-apt-repository ppa:ondrej/php --force-yes
Create an alias for shell commands
Add the script below at end of the file
~/.profile
alias hello_world="echo \"Hello World!\""
Then type your alias directly
hello_world
# output: Hello World
Update packages less noisy
apt-get -qq update
Revalidade ca-certificates
sudo apt-get install -y --reinstall ca-certificates
Add multi-touch to your Linux distribution
To do it, make sure to do the steps below:
sudo gpasswd -a $USER input
sudo apt install xdotool wmctrl libinput-tools
git clone https://github.com/bulletmark/libinput-gestures
cd libinput-gestures
sudo ./libinput-gestures-setup install
touch ~/.config/libinput-gestures.conf
Paste the content below inside
~/.config/libinput-gestures.conf
:
gesture swipe up 3 xdotool key super+Down
gesture swipe left 3 xdotool key super+Right
gesture swipe right 3 xdotool key super+Left
After that execute the commands below
libinput-gestures-setup autostart
libinput-gestures-setup start
libinput-gestures-setup restart
References:
Get SO information
sudo apt-get install screenfetch -y
screenfetch
Know where the program was installed
which php
Show any configured swap
sudo swapon --show
Observe and monitor system memory usage
free -h
Downgrade Ubuntu Linux system version
Downgrade sources.list
sudo sed -i 's/groovy/focal/g' /etc/apt/sources.list
Pin packages
Package: *
Pin: release a=focal v=20.04
Pin-Priority: 1001
Downgrade Ubuntu system
sudo apt update ; sudo apt upgrade ; sudo apt dist-upgrade
If you found any errors try this:
sudo apt --fix-broken install
sudo dpkg --configure -a
sudo apt dist-upgrade
sudo apt install ubuntu-desktop
Find and remove folder recursively
# Example: node_modules
sudo find . -type d -name node_modules -exec rm -r {} \;
Open Mac External Harddrive on Linux
- [x] sudo apt-get install hfsprogs
- [x] Mount volume
or
- [x] chmod -R 777 /user/media/volumeX
# df -h
# sudo mount -t hfsplus -o remount,force,rw /dev/sdg1
apt install xrdp
adduser xrdp ssl-cert
systemctl restart xrdp
# Allow firewall access on port 3389
ufw allow 3389
# Change "allowed_users" to anybody
# like this: allowed_users=anybody
vim /etc/X11/Xwrapper.config
# Check your hostname
cat /etc/hostname
# Or get your ip address
if config
Install Postman
sudo apt update
sudo apt install snapd
sudo snap install postman
Unzip with the destination folder
Set -d parameter
unzip package.zip -d /opt
How to Install netstat Command in Linux
# [On CentOS/RHEL]
yum install net-tools
# [On Debian/Ubuntu]
apt install net-tools
# [On OpenSuse]
zypper install net-tools
# [On Arch Linux]
pacman -S netstat-nat
netstat -r -n
Show subnet
ip -o -f inet addr show | awk '/scope global/ {print $2, $4}'
Show gateway
ip route | grep default
User & Groups
Create new user
sudo adduser newuser
Add an existing user to the Sudo group
sudo usermod -aG sudo newuser
Bluetooth device disconnects right after connect
Remove the device on Pulse Audio Bluetooth Devices
Kill pulse audio and restart the Bluetooth service
sudo killall pulseaudio && sudo service bluetooth restart
Bash/Zsh undo (CTRL + Z)
Type: CTRL + /
Last updated
Was this helpful?