piszczynski>Aleks |
piszczynski>Aleks (→Sort) |
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*<command> | sort | *<command> | sort | ||
*sort <options> <filename> | *sort <options> <filename> | ||
---- | |||
Sort on numerical value: | Sort on numerical value: | ||
*sort -n | *sort -n | ||
---- | |||
sort in reverse order: | sort in reverse order: | ||
*sort -r | *sort -r | ||
---- | |||
Sort by specific column (useful with commands that return data in columns like du) | Sort by specific column (useful with commands that return data in columns like du) | ||
*sort -k <column number> | *sort -k <column number> | ||
*sort -k 3nr (will sort by the 3rd column in reverse number order) | *sort -k 3nr (will sort by the 3rd column in reverse number order) | ||
---- | |||
Sort and remove duplicates | Sort and remove duplicates | ||
*sort -u | *sort -u |
Revision as of 10:42, 11 September 2023
Basic Commands
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>
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 -a
- ip link
Set the network interface settings on the configuration file:
- 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
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