Archives For command skills

Familiar with Linux commands? You may already know many tips and tricks that will save you a lot of time.

Here are some that I have been using for a long period of time, including Tab auto-completion, when you type something in Linux terminal and hit Tab, it auto-completes the command or file path, or outputs all possible options.

And Ctrl+Shift+V will do paste text to terminal instead of Ctrl+V. Without copying to the clipboard, you can simply select / highlight the text and use mouse middle-click to paste into terminal.

Today I found a new terminal tips that I didn’t know before. Thanks to the reddit, I’m going to share it with you by following steps.

1. Drag and drop file or folder to paste the path into terminal.

Just drag and drop a file or folder into terminal, and you’ll see the full path pasted with single quotes. It’s useful if there’s special character in file path or you just don’t want to type …

2. Drag and drop a selection of text into terminal.

You can also drag and drop a selection of text into terminal, so you don’t need to do copy and paste with context menu clicks or keyboard shortcuts.

This is a step by step beginner guide shows how to check local network IP and public IP in both IP4 and IPv6 via either graphical interface or Linux commands in Ubuntu 20.04.

1. Find IP address via System Settings:

For the default Gnome desktop, you can check the wireless network IP address via:

  • Open Settings and navigate to Wi-Fi in left pane.
  • Click on the gear icon after the connected wifi network.
  • In the pop-up it shows the detailed information including your IP address.

To check the wired network IP address, do:

  • Open Settings and navigate to Network in left pane.
  • Click on the gear icon under connected wired network.
  • In the pop-up it shows the detailed information including your IP address.

2. Check Local IP address via ifconfig command:

While wired network name is usually eth0, eth1, eno1, wireless network name is usually wlan0, wlan1, wlo1, …

For other desktops or Ubuntu server without an UI, you can run ifconfig command to find your IP.

ifconfig

If the command does not exit, run command to install it: sudo apt install net-tools

3. Check Local IP address via ip command:

There’s another command looks more straightforward. Simply run:

ip address

4. Check Your Public IP address:

You can search your public ip via Google or other web search engine. If you don’t have a web browser or you’re on Ubuntu server, following commands will tell the public IP.

ifconfig will tell the public IP if you are not behind a router.

Or you can run command in console:

curl https://ipinfo.io/ip

internet speed test

Want to test your internet bandwidth without opening web browser? Well, here’s command line tool to do this using speedtest.net.

This may be help if you’re on Ubuntu Linux servers that doesn’t have a GUI. The tool is based on Python 2.4-3.3, so it works on all Canonical supported Ubuntu releases.

To install the tool, speedtest-cli:

1.) First install python-pip, a tool for installing and managing Python packages. To do so, run below command:

sudo apt-get install python-pip

2.) Install speedtest-cli via python-pip:

sudo pip install speedtest-cli

Once installed, you can use one command to test your internet bandwidth. The command is:

speedtest

You’ll see the similar output, which display you internet bandwidth as well as ISP & IP address.

Retrieving speedtest.net configuration…
Retrieving speedtest.net server list…
Testing from M-net Telekommunikations GmbH (88.217.180.40)…
Selecting best server based on ping…
Hosted by InterNetX GmbH (Munich) [2.23 km]: 18.756ms
Testing download speed………………………………….
Download: 7.81 Mbit/s
Testing upload speed…………………………………………..
Upload: 3.46 Mbit/s

NRG A .nrg file is a proprietary CD image file format used by Nero Burning ROM. In Ubuntu Linux, you can easily convert the .nrg to .iso file using the command line tool nrg2iso.

nrg2iso is available in Ubuntu universe repository. You can install it using Ubuntu Software Center. Or run below command if you’re on Ubuntu Server without GUI:

sudo apt-get update; sudo apt-get install nrg2iso

Once installed, you can convert .NGR file to .ISO via one command. For example:

nrg2iso image.nrg image.iso

That’s it. Enjoy!

If you’re dual booting Ubuntu with Windows 7 or other Operating Systems, you may wish to change boot order to set which OS starts by default. Well, In this tutorial I’ll show you how to do it in Ubuntu 13.10 Saucy and 13.04 Raring.

grub2 boot loader

There’s a GUI (graphical user interface) tool for editing Grub 2 boot loader, it called Grub-Customizer. You can install it in Ubuntu using the PPA repository. To do so, press Ctrl+Alt+T to open terminal, then run below commands one by one:

sudo add-apt-repository ppa:danielrichter2007/grub-customizer

sudo apt-get update

sudo apt-get install grub-customizer

With Grub-Customizer, highlight the OS entry and click up / down arrow button to change its order. Or set the default OS in General Settings tab.

change boot order via grub customizer

If you’re comfortable with running some terminal commands, it’s not difficult to change default OS without installing any third-party program.

1.) Press Ctrl+Alt+T to open terminal. Edit the “/etc/default/grub” via below command and change GRUB_DEFAULT=0 to GRUB_DEFAULT=saved. This will make it easy to change default OS later.

sudo gedit /etc/default/grub

2.) Update grub to apply changes to grub configuration:

sudo update-grub

3.) After that, you can run sudo grub-set-default with the number of menu entry to boot (the first entry is 0) at any time, which will set the entry as default OS permanently. Or run sudo grub-reboot only for next boot.

For example, below command will set Windows 7 as default OS (Windows 7 is 4 in picture at top) permanently.

sudo grub-set-default 4