Line 98: | Line 98: | ||
Get ip address and interfaces with: | Get ip address and interfaces with: | ||
<syntaxhighlight lang="bash">ifconfig</syntaxhighlight> | <syntaxhighlight lang="bash">ifconfig</syntaxhighlight> | ||
<syntaxhighlight lang="bash">ip -a</syntaxhighlight> | <syntaxhighlight lang="bash">ip -c a</syntaxhighlight> | ||
<syntaxhighlight lang="bash">ip link</syntaxhighlight> | <syntaxhighlight lang="bash">ip link</syntaxhighlight> | ||
Set the network interface settings on the configuration | Set the network interface settings on the configuration files located in the netplan directory. Netplan will parse all the files in this directory: | ||
<syntaxhighlight lang="bash">sudo nano /etc/netplan/<name of config file eg 00-installer-config.yaml></syntaxhighlight> | <syntaxhighlight lang="bash">sudo nano /etc/netplan/<name of config file eg 00-installer-config.yaml></syntaxhighlight> | ||
Line 116: | Line 116: | ||
addresses: [192.168.50.3, 1.1.1.1] | addresses: [192.168.50.3, 1.1.1.1] | ||
version: 2 | version: 2 | ||
</pre> | </pre>Apply the changes using netplan apply:<syntaxhighlight lang="bash"> | ||
sudo netplan apply | |||
</syntaxhighlight> | |||
== Swap File == | == Swap File == |
Revision as of 18:51, 4 February 2024
Basic Commands
Useful everyday commands
List directory contents:
ls
in long format -l
list all -a
List block devices (all drives)
lsblk
in list: -l
Get info on system
uname -a
Change file mode bits (file permissions)
chmod <options> <filename>
chmod 777 script.sh (gives read write execute permission to owner, group, world)
Change ownership of file
chown <newowner>:<newgroup> <filename>
chown dave:users notes.txt
Compress file
tar -zxvf <filename>
tat -zxvf something.tar.gz
extract:
tar -xvf something.tar.gz
Display file contents or join files
cat <filename>
join files:
cat file1.txt file2.txt
combine files:
cat file1.txt file2.txt >> file3.txt
Copy
Copy a file:
cp <file> <Destination>
copy multiple files:
cp <file1> <file2> <Destination>
Prevent overwriting: (will overwrite files by default)
cp -n <source> <dest> (can also use -i option to decide for each file)
Copy directory:
cp -r <source> <destination>
Copy contents of directory to another directory:
cp <source>/. <destination>
Sort
Pipe output to sort to sort it or display contents of file sorted:
<command> | sort
sort <options> <filename>
Sort on numerical value:
sort -n
sort in reverse order:
sort -r
Sort by specific column (useful with commands that return data in columns like du)
sort -k <column number>
sort -k 3nr (will sort by the 3rd column in reverse number order)
Sort and remove duplicates
sort -u
Ignore case when sorting
sort -f
sort by human numeric values:
sort -h
Redirect output to another file:
sort > <other file>
zip
Decompress tar.gz files:
tar –xvzf documents.tar.gz
Get Linux Info
Get current build and Linux OS data:
cat /etc/os-release
Remote Desktop Protocol App for linux
Remmina can be used for RDP connections to windows computers using RDP as well as VNC SSH and others
To user also need to install xrdp and tightvnc:
sudo apt install xrdp xorgxrdp -y
echo env -u SESSION_MANAGER -u DBUS_SESSION_BUS_ADDRESS cinnamon-session>~/.xsession
Other newer option is xserver-xorg-core
Change or Set IP address
With Newer Ubuntu versions netplan is used as the network management tool.
Get ip address and interfaces with:
ifconfig
ip -c a
ip link
Set the network interface settings on the configuration files located in the netplan directory. Netplan will parse all the files in this directory:
sudo nano /etc/netplan/<name of config file eg 00-installer-config.yaml>
Example of the .yaml file:
network: ethernets: ens160: dhcp4: no addresses: - 192.168.50.15/24 gateway4: 192.168.50.1 nameservers: addresses: [192.168.50.3, 1.1.1.1] version: 2
Apply the changes using netplan apply:
sudo netplan apply
Swap File
Check size of swap file:
swapon -s
increase swap file to 8GB:
sudo swapoff -a #turn off swap file
sudo dd if=/dev/zero of=/swapfile bs=1M count=8192 #set size of blocks for swap file and create
sudo chmod 0600 /swapfile #Assign it read/write permissions for root only
sudo mkswap /swapfile #Format the file as swap
sudo swapon -a #enable swap file - will also be activated on next reboot without this command
Alternate commands to make 8GB swap file
sudo swapoff /swapfile
sudo rm /swapfile
sudo fallocate -l 8G /swapfile
App Image
Apps can be downloaded as an appimage which is the application with everythign it needs to run in one file.
You will need to make the appimage executable to be able to run it:
chmod u+x <appimage file>
SSH
Enable SSH
Install openssh server:
sudo apt-get install openssh-server
login.
Enable login using ssh Keys
Generate keys: Be careful if you have already generated a key as this will overwrite the current key
ssh-keygen
This gets stored in ~/.ssh
Copy key to server (must have ssh via password enabled)
ssh-copy-id name@server
This gets sored on remote server in ~/.ssh/authorized_keys file. you can append keys to this fille to add more logins:
cat ~/.ssh/id_rsa.pub | ssh name@server "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"
Copy over manually:
Check public key
cat ~/.ssh/id_rsa.pub
Make dir:
mkdir -p ~/.ssh
copy key over:
echo <public_key_string> >> ~/.ssh/authorized_keys
Disable Password Authentication
Edit config file:
sudo nano /etc/ssh/sshd_config
Change:
PasswordAuthentication no
Restart ssh service:
sudo systemctl restart ssh