How do I do my daily math on Linux ?

To do my daily math on Linux I use my terminal. Yes, on the terminal.

I use GNU/Octave in CLI mode to have a powerful calculator straight on the terminal.

https://octave.org/

The usage

The usage is very simple, I just press the keyboard shortcuts to open my terminal on Debian GNU/Linux and, after that, I type the character that will run a bash script to open my CLI GNU/Octave prompt and enter with the math expressions.

How to do this setup

The first thing you need to do is install the GNU/Octave on your Unix System.

On Debian or other Linux distributions, just use your system package manager.

For Debian-based distributions just type the command:

sudo apt install octave

At this moment, you can access the octave-cli by typing the command:

octave-cli

The result is

Note that when you access Octave this way, version, license, website, etc. information is displayed. A standard prompt is offered too.

To hide the help information, you need to type the following command:

octave-cli -q

Use -q to a quiet enter.

To change the prompt we need to evaluate a built-in function.

octave-cli -q --persist --eval "PS1('>> ')"

• -q to a quiet enter
• --persist to evaluate some code and to continue into the octave
• PS1(' your prompt ') - Built-in function to change the prompt

Let's write a bash script to automate all these steps

Open a text editor and write the following instructions:

#!/bin/bash
a="system('clear')"
b="PS1('>> ')"
octave-cli -q --persist --eval "$a;$b;clc"        

• #!/bin/bash - set the SHELL (I like to use bash, and this is the standard SHELL on Debian)
• a="system('clear')" - Built-in octave function to run a Linux command to clear the terminal.
• b="PS1('>> ')" - Built-in function to change the prompt (You can customize it here.)
• octave-cli -q --persist --eval "$a;$b;clc" - run a quiet octave-cli command and evaluate the $a and $b instructions. The clc built-in function will clear the octave screen.

Save this file into a known folder with the wanted name for your calculator. Example:

/home/'username'/bash/calc -here we save the file with the calc name into the [bash] directory.

After saving the file, set the file permissions as an executable file.

chmod +x calc

The ultimate step is to define the [bash] directory as an environment directory.

Into the hidden system files .bashrc or .bash_aliases in your home directory, include the following instructions:

export PATH=~/bash:$PATH

Now, just open your terminal, type 'calc', and enjoy it.