Sharing of how I made my own command

#beginners #ubuntu

Weekly sharing

Hi everyone, I am Ekim, a fresh Bootcamp graduate and an IT helper (I don't dare to call myself a programmer yet). Every Friday, I will share some of the work that I've done over the last week in a bid to get feedbacks from you guys and record my journey to become a programmer.

Introduction

Last week was a hectic journey. I didn't have much time working on blog writing. So this blog wouldn't be as detailed as others I've written. Despite that, I would like to share with you some tips for making your own command on Ubuntu.

Previously

Multi-Master VRRP set-up

How I made my own command ?

Writing in ~./bashrc

After writing a .js file or other kinds of files, you could run it with node or other runtime tools.
In the ~./bashrc, we could make use of alias to help us run those files in a much easier way
For example to execute node abcd.js, we could make it with as simple as only one word abcd
Here is how we could do it

       alias abcd="node /var/local/abcd.js"

The down side of writing alias in ~./bashrc is that the script can only be used by the users whose ~./bashrc has those script.
If there are multiple accounts in the server, you could not make sure that everyone could use that shortcut

Writing an executable at /usr/local/bin

An executable is a file which is set to be executed
In that file, you specify how the script is run
Using the above abcd as an example, what you need is the following

       cd /usr/local/bin
       touch abcd
       chmod a+x ./abcd         # enable execution for all groups

       # edit the executable
       vim abcd

       # ------- vim abcd -------
       #!bin/bash

       node "/var/local/abcd.js"
       # ------- vim abcd -------

By doing so, every user could use the abcd command
If the abcd.js accepts 3 arguments, which you include something like let [ var1, var2, var 3] = process.argv.slice(2) in your .js file to get the arguments , you could further do this

       # ------- vim abcd -------
       #!bin/bash

       node "/var/local/abcd.js" $1 $2 $3
       # ------- vim abcd -------

Conclusion

Now, you have created a command called abcd in your system. Input your newly created command into your console and see if it could run as expected. If I did anything wrong, please let me know as well. That's all for today. I hope you enjoy reading.