Shahnawaz Hossan — Posts

Getting Started with Vim

Sun, 22 Mar 2020 00:00:00 GMT

     🔰 Introduction
     🔰 Modes
     🔰 Movements
     🔰 Insert
     🔰 Find
     🔰 Go to
     🔰 Search
     🔰 Remove and Delete
     🔰 Replace and Repetition
     🔰 Visual Mode
     🔰 Practice

🔰 Introduction

Vim is one of the most powerful text editors I have ever used in CLI(Command Line Interface). There are so many files which need to be opened or edited. Vim can be the best choice because Vim is more than an editor. 😎

Installation commands on Ubuntu:

$ sudo apt update
$ sudo apt install vim

🔰 Modes

There are two basic modes in Vim.

insert mode (In this mode you can edit texts in your own way).
normal mode (In this mode you can manipulate and play with texts according to some instructions).

To switch between these modes you need to use Esc for normal mode and i for insert mode.

There is another mode in vim called visual mode. It is described here.

🔰 Movements

🚶 Basic Movements

You can move the cursor using following keys instead of uding arrow keys:

h for moving towards left.
l for moving towards right.
k for moving towards up.
j for moving towards down.

🚶 Word Movements

Movement between words is possible via these keys:

w or W for moving to the beginning of the next word from current cursor and will continue.
b or B for moving to the beginning of the previous word from current cursor and will continue.
e or E for moving to the end of the next word from current cursor and will continue.

Use number before these keys for moving fast e.g. 3w or 3W means cursor will move to the beginning of the 3rd next word.

🔰 Insert

📝 Insert Text Repeatedly

Suppose you want to insert yes 30 times consecutively. Steps will be as follows:

Write 30 in normal mode.
Then press i, vim will be switched from normal mode to insert mode.
Write yes then press Esc.

You will see that yes has been written 30 times consecutively.

📝 Insert New Line

By pressing o or O, a new line will be inserted and vim will be switched to insert mode as well.

🔰 Find

👓 Find a Character.

Press fq to find next q.
Press Fq to find previous q.
Press 3fq to find 3rd next occurrence of q.
Press 3Fq to find 3rd previous occurrence of q.

👓 Find word under cursor

Press * to find the next occurrence of the word under current cursor.
Press # to find the previous occurrence of the word under current cursor.

🔰 Go to

Go to matching parentheses ((), {}, []) by simply pressing %.
Press 0 to go to the start of the line.
Press $ to go to the end of the line.
Press gg to go to the beginning of the file.
Press G to go to the end of the file.
Press G with number before to go to the specific line e.g. press 3G to go to the 3rd line.

🔰 Search

You can search a specific text in a file i.e. for searching text in your file, steps will be as follows:

Write /text and then hit Enter button.
After that press n, it will find the next text from the file and so on.
Press N, it will find the previous text from the file and so on.

🔰 Remove and Delete

✂️ Removing a Character

By pressing x, the character under the cursor will be removed.
By pressing X, the character to the left of the cursor will be removed.

✂️ Deleting

The delete key is d. You can use it with movements' keys.

E.g. dw will delete the first word on the right side of the cursor. It also copies the deleted content so that you can paste it to another location by pressing p.

🔰 Replace and Repetition

🚜 Replace

For replacing a letter under cursor:

Press r and then write replaceable letter e.g. a to replace cursor’s letter by a.

🚜 Repetition

Repeat the previous command by pressing simply .

E.g.

d2w will delete next two words of current cursor.
After that if you press ., the previous command i.e. next two words will also be deleted and so on.

🔰 Visual Mode

To switch to visual mode, just press v. In this mode you can select a text via movement keys.

E.g.

Press v and then e to select a word.
After that press d to delete that word.

🔰 Practice

When you change the file in vim you have to know these commands as well:

:w (save)
:wq (save and quit)
:q (quit)
:q! (quit without saving)
u (For undo)
ctrl+R (For Redo)
:help (For Help)

This article is written according to this website. You can practice above commands in realtime. 🎉🎉🎉

Custom Fonts in React Native Android

Fri, 20 Dec 2019 00:00:00 GMT

Version of react-native > 0.60

Firstly download your fonts from Google Fonts. Suppose you have downloaded Lato font. Then create an assets folder, react-native.config.js file into your react-native’s root directory and copy all the .ttf files extracted from downloaded zip file. Add following codes into react-native.config.js file.

module.exports = {
  project: {
    ios: {},
    android: {}
  },
  assets: ['./assets/fonts/']
}

Then run this command in your project’s directory.

$ react-native link

Add fontFamily: 'Lato-Bold' in your StyleSheet and run

$ react-native run-android

Hopefully you can see your added font.

Setup React Native environment on Ubuntu

Wed, 11 Dec 2019 00:00:00 GMT

🔦 Install node and npm

⛵ Using Ubuntu

$ sudo apt install curl
$ curl -sL https://deb.nodesource.com/setup_10.x | sudo -E bash -
$ sudo apt-get install -y nodejs
$ node -v
v10.17.0
$ npm -v
6.11.3

⛵ Using Debian, as root

$ curl -sL https://deb.nodesource.com/setup_10.x | bash -
$ sudo apt-get install -y nodejs

🔦 Install react-native-cli

$ sudo npm install -g react-native-cli
$ react-native --version
react-native-cli: 2.0.1

🔦 Setup Android development environment

Download android studio. In my case downloaded file’s name was android-studio-ide-191.6010548-linux.tar.gz and I kept it into my home directory. Then follow these steps

$ cd ~
$ tar xvzf android-studio-ide-191.6010548-linux.tar.gz
$ cd android-studio/bin/
$ ./studio.sh

After completing the installation of android studio, you need to install these from android studio.

Android SDK
Android SDK Platform
Android Virtual Device

To do that just go to Appearance & Behavior → System Settings → Android SDK from android studio and select your SDK platform and install.

Then you need to set up ANDROID_HOME environment variables in order to build react native apps with native code. Now edit your .bashrc file and add these lines into it.

export ANDROID_HOME=$HOME/Android/Sdk
export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/tools/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools

After adding those lines save it and run source .bashrc via terminal to keep running source to get the aliases working in any new login terminal instances.

$ source .bashrc

🔦 Install java on your Ubuntu system

$ sudo apt update
$ sudo apt install default-jdk
$ java -version
# Output
openjdk version "11.0.4" 2019-07-16
OpenJDK Runtime Environment (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3)
OpenJDK 64-Bit Server VM (build 11.0.4+11-post-Ubuntu-1ubuntu218.04.3, mixed mode, sharing)

So you have successfully installed java on your Ubuntu system. My version was Ubuntu 18.04.3 LTS. At this point you are all set of working with react-native.

🔦 Test your first react-native app

First connect your android phone with a usb. Then run these commands

$ react-native init testReactApp
$ cd testReactApp/
$ react-native start

# Open another terminal, go to testReactApp's directory and run this command
$ react-native run-android

After a while, you will see your running app into your android phone.

~ Good Luck and Have fun ⛄ ~

Perceiving about Linux Distros

Wed, 04 Dec 2019 00:00:00 GMT

     ❓ What is Linux?
     ✊ How it differs from UNIX?
     🎬 Linux Distributions

❓ What is Linux?

One of the most-used and best-known operating systems is Linux that distributed under an open source license. Technically it refers only to the kernel of the operating system. Kernel is the heart of any operating system which takes care of elementary stuffs. Linux is largely compatible with the UNIX.

✊ How it differs from UNIX?

UNIX is the mother of all operating systems. Linux was basically created to be similar to UNIX. So commands using on both operating systems are usually the same. Programming tools, other key components are similar as well. And main part is, you have to pay for a UNIX kernel but Linux is totally free and open source.

🎬 Linux Distributions

After initial realeses of Linux in the early 1990s, many bundles of software came to complement the Linux kernel which were brought by many organizations. These bundles are called distributions. These are about which version of what software. Packages are softwares and applications that are bundled. So Linux Distributions are classified by these package types. There are three basic types of packages:

Debian Based Linux Distros
RedHat Package Manager(RPM)
Other Distributions

🍴 Debian Based Linux Distros

The package extension of Debian is .deb. New distributions are based on Debian. It’s one of the oldest and very popular choice of Linux Distributions. Some distributions that use .deb packages are as follows

Debian
Ubuntu
Linux Mint
antiX
Raspbian etc.

🍴 RedHat Package Manager

Package extension of this types of distros is .rpm. Distributions of this type are

🍴 Other Distributions

Some other distributions are

Arch Linux
Slackware Linux
Gentoo Linux
LXDE (Desktop Manager) (e.g. Lubuntu)
XFCE (Desktop Manager) (e.g. Xubuntu) etc.

You can see various types of Linux Distributions here

Getting Started with Snap

Wed, 27 Nov 2019 00:00:00 GMT

     ✋ Getting Started
     🔧 Setting Up
     🏃 Install and Run your first Snap
     💬 More Features

✋ Getting Started

Snap (or Snappy package manager) is one of the best software deployment and package management system which is built by Canonical.
A snap is a bundle of an app and works across many different Linux distributions as well.
App packages that are installed through snap, called Snaps. So Snaps are containerized software packages.
These are disclosable and installable from the Snap Store.
snapd is the tool for using snaps.

The system is actually designed for IoT, Cloud and Desktop Computing that are

Easy to install
Secured
Cross-Platform
Dependency-free

🔧 Setting Up

📝 Installing `snapd` on Ubuntu

$ sudo apt install snapd

It manages the snap environment on local the system and will include the snap tool for interacting with snaps as well. You can check whether snap is installed or not by running snap version on the command line:

$ snap version
snap    2.42.1
snapd   2.42.1
series  16
ubuntu  18.04
kernel  5.0.0-36-generic

🏃 Install and Run your first Snap

📝 Finding a `snap`

$ snap find something
Name                 Version       Publisher       Notes    Summary
paintsupreme-3d      1.0.41        braindistrict   -        PaintSupreme 3D
syncthing            1.3.1         syncthing✓      -        Open Source Continuous File Synchronization
openscad-nightly     0+git.eedfcc4 torsten-paul    -        The Programmers Solid 3D CAD Modeller
step                 19.08.0       kde✓            -        Simulate physics experiments
draftman             1.0.12        jsseidel        classic  A plain-text draft management tool for novelists.
spt                  v0.4.0        popey           -        Spotify TUI

snap find <search keywords> queries the store and list the results with their details. ✓ indecates that publisher has been verified.

📝 Learning about a `snap`

$ snap info hello
name:      hello
summary:   GNU Hello, the "hello world" snap
publisher: Canonical✓
contact:   snaps@canonical.com
license:   GPL-3.0
description: |
  GNU hello prints a friendly greeting. This is part of the snapcraft tour at https://snapcraft.io/
snap-id: mVyGrEwiqSi5PugCwyH7WgpoQLemtTd6
channels:
  stable:    2.10    2019-04-17 (38) 98kB -
  candidate: 2.10    2017-05-17 (20) 65kB -
  beta:      2.10.1  2017-05-17 (29) 65kB -
  edge:      2.10.42 2017-05-17 (34) 65kB -

You will know details about a package by running this command.

📝 Install and execution

$ sudo snap install hello
hello 2.10 from Canonical✓ installed

For running the command simply write hello in the command line.

$ hello
Hello, world!

📝 Keep tracking installed `snaps`

$ snap list
Name                  Version                     Rev   Tracking  Publisher   Notes
core                  16-2.42.1                   8039  stable    canonical✓  core
core18                20191030                    1265  stable    canonical✓  base
gnome-3-28-1804       3.28.0-16-g27c9498.27c9498  110   stable/…  canonical✓  -

Installed snaps on your system will be listed by this command.

📝 Refreshing an installed `snap`

$ sudo snap refresh hello
snap "hello" has no updates available

Above command will check whether a newer version is available or not and it will be downloaded and installed automatically.

$ sudo snap refresh --channel=beta hello
hello (beta) 2.10.1 from Canonical✓ refreshed

You can change the channel from which your snap will be tracked and refreshed with this single command.

💬 More Features

📝 Reverting an installed `snap`

$ sudo snap revert hello
hello reverted to 2.10

$ snap list --all hello
Name   Version  Rev  Tracking  Publisher   Notes
hello  2.10     38   beta      canonical✓  -
hello  2.10.1   29   beta      canonical✓  disabled

Above command will list all revisions of hello.

Revision is the sequence number which is assigned by the store when it was uploaded

$ snap list --all

This will list all revisions available for every installed snaps.

📝 Enabling and Disabling a `snap`

$ sudo snap disable hello
hello disabled

$ sudo snap enable hello
hello enabled

📝 Removing a `snap`

$ sudo snap remove hello
hello removed

After running this command, all snap’s revisions will be removed. To remove specific revision add --revision=<revision-number> to the remove command.

Remove files/folders from remote repository

Wed, 20 Nov 2019 00:00:00 GMT

If you want to remove a folder from your git repository then simply run these commands into your terminal.

Run

$ rm -rf folder_name
$ git add --all
$ git commit -m "Your commit message"
$ git push origin "branch_name"

These commands will remove that folder from your git repository of that branch.

Save username and password in GIT

Wed, 13 Nov 2019 00:00:00 GMT

Run

$ git config --global credential.helper store

After running this command, when you push to your repository or pull from your repository, you’ll get asked username and password for first time. Then credentials will be stored into your home directory named .git-credentials file in plaintext.

You can use this command to store your credentials into cache memory for specific time(in seconds).

$ git config --global credential.helper 'cache --timeout=14400'

This command will remember your credentials for 4 hours. Your username and password will be asked for the first time during push or pull as well.

These commands will store your username, password and email in .gitconfig file into your home directory.

$ git config --global user.name "your username"
$ git config --global user.password "your password"
$ git config --global user.email "your email"

Storing global email would help you to count your github contribution during commits.

Install Jekyll on Ubuntu

Wed, 13 Nov 2019 00:00:00 GMT

Jekyll is one of the popular static site generators. To work with Jekyll, you need to have all the required dependencies.

$ sudo apt-get update
$ sudo apt-get install ruby-full build-essential zlib1g-dev

Setup gems installation directory for your user account to avoid installing Ruby Gems as the root user. You will found this informed on Jekyll’s website. So add environment variables to ~/.bashrc file to configure installation path.

$ echo '# Install Ruby Gems to ~/gems' >> ~/.bashrc
$ echo 'export GEM_HOME="$HOME/gems"' >> ~/.bashrc
$ echo 'export PATH="$HOME/gems/bin:$PATH"' >> ~/.bashrc
$ source ~/.bashrc

Now install Jekyll by running this

$ gem install jekyll bundler

To create your own blog and test it, run the following

$ jekyll new myblog
$ cd myblog
$ bundle exec jekyll serve

Your site will be running on http://localhost:4000.

Congratulations you’ve successfully run your own site.

Shahnawaz Hossan — Posts

Getting Started with Vim

Table of Contents

🔰 Introduction

🔰 Modes

🔰 Movements

🚶 Basic Movements

🚶 Word Movements

🔰 Insert

📝 Insert Text Repeatedly

📝 Insert New Line

🔰 Find

👓 Find a Character.

👓 Find word under cursor

🔰 Go to

🔰 Search

🔰 Remove and Delete

✂️ Removing a Character

✂️ Deleting

🔰 Replace and Repetition

🚜 Replace

🚜 Repetition

🔰 Visual Mode

🔰 Practice

Custom Fonts in React Native Android

Version of react-native > 0.60

Setup React Native environment on Ubuntu

🔦 Install node and npm

🔦 Install react-native-cli

🔦 Setup Android development environment

🔦 Install java on your Ubuntu system

🔦 Test your first react-native app

~ Good Luck and Have fun ⛄ ~

Perceiving about Linux Distros

Table of Contents

❓ What is Linux?

✊ How it differs from UNIX?

🎬 Linux Distributions

🍴 Debian Based Linux Distros

🍴 RedHat Package Manager

🍴 Other Distributions

Getting Started with Snap

Table of Contents

✋ Getting Started

🔧 Setting Up

📝 Installing snapd on Ubuntu

🏃 Install and Run your first Snap

📝 Finding a snap

📝 Learning about a snap

📝 Install and execution

📝 Keep tracking installed snaps

📝 Refreshing an installed snap

💬 More Features

📝 Reverting an installed snap

📝 Enabling and Disabling a snap

📝 Removing a snap

Remove files/folders from remote repository

Run

Save username and password in GIT

Run

Install Jekyll on Ubuntu

📝 Installing `snapd` on Ubuntu

📝 Finding a `snap`

📝 Learning about a `snap`

📝 Keep tracking installed `snaps`

📝 Refreshing an installed `snap`

📝 Reverting an installed `snap`

📝 Enabling and Disabling a `snap`

📝 Removing a `snap`