Using different Versions of Node using NVM

 To check your current active version of Node and NPM

node -v

npm -v

Node 10.7.0

Node is most easily managed using NVM and that is the recommended tool we suggest. https://github.com/creationix/nvm

Now, suppose you have different version of node installed, but some app needs a lower or a different version. Then what to do. Here comes nvm for the rescue!

nvm is a version manager for node.js, designed to be installed per-user, and invoked per-shell. nvm works on any POSIX-compliant shell (sh, dash, ksh, zsh, bash), in particular on these platforms: unix, macOS, and windows WSL.

Install & Update Script

To install or update nvm, you should run the install script. To do that, you may either download and run the script manually, or use the following cURL or Wget command:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.36.0/install.sh | bash

Do not forget to source the bash profile after this:

Simply type source ~/.bash_profile

Alternatively, if you like saving keystrokes you can type . ~/.bash_profile




Now you can use nvm commands to change node version

eg:

nvm install 10.7

or, nvm use 10.7

Find version of Modules using PIP : Python Installation manager

Use pip list to list all packages and their versions. You can pipe it to grep to search for the package your interested in:

pip list | grep sympy

Alternatively to get all information about that package including version you can use pip show:

pip show sympy

To upgrade it's simply:

pip install --upgrade sympy

If you need write permissions to your python installation directory don't forget to prepend the pip install command with a sudo: e.g. sudo pip install --upgrade sympy

** With latest Python, you might need to replace pip with pip3 command.

First Hello World using Hack & HHVM from Facebook

1. Install HHVM on MacOS via Homebrew:

brew tap hhvm/hhvm
brew install hhvm

The out-of-the-box HHVM configuration won't need tweaking by most new users. Notably, the JIT compiler that gives HHVM its speed is on by default. If you want to take a look at the configuration used, it's at /usr/local/etc/hhvm/php.ini in MacOS.

2. Test: After installing HHVM, change to the directory where your code lives, and start up HHVM:

hhvm -m server -p 8080

-m represents the mode and here indicates that HHVM is running in HTTP server mode.

-p configures the TCP port that HHVM uses to listen to HTTP requests. The default port is 80, the standard HTTP port. However, that port requires root access, so for this example, we will use port 8080.

This will start the server as follows and then you can test on browser.

3. Write a simple "Hello World" program named hello.hack:

<<__entrypoint>> function main(): noreturn{ echo "Hello World in Hack Language! \nThis is Anwar Jamal Faiz"; exit(0); }

Save this hello.hack in the same directory that you ran the hhvm command from above. Then, load http://localhost:8080/hello.hack in your browser and verify you see "Hello World!" appear.


See in browser:

You may also write the program as:

<<__entrypoint>>
function main(): noreturn{
  echo "Hello World in Hack Language! \nThis is Anwar Jamal Faiz";
  exit(0);
}

4.  You can directly run file using hhvm itself.

$ hhvm hello.hack

Note: You can configure HHVM too. Running HHVM automatically at boot as a service (instead of just on the command line as above) unfortunately does require some configuration. See the proxygen documentation for details. However, default settings are okay for any average usecase.

How to install Redis and run its instance

First, step first. You can simply install it using homebrew
$ brew install redis

After installation you can check that it creates a configutration file at:
/usr/local/etc/redis.conf

Then, you can verify the install as follows:
$ brew info redis

You can start an instance i.e Start Redis server using the configuration file.
$ redis-server /usr/local/etc/redis.conf

By default, it Runs in standalone mode on Port: 6379


Test if Redis server is running.
$ redis-cli ping
It will replu=y you pong!

To Uninstall Redis and its files.
$ brew uninstall redis


What more do you want. So cheers.
:)

How to install Homebrew (brew command) on Mac, linux

To Install Homebrew, you need to make use of ruby that is already installed. This is a simple command then.

On your terminal use following:

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
Paste that in a macOS Terminal prompt.

The script explains what it will do and then pauses before it does it. Read about other installation options. Install Homebrew on Linux and Windows Subsystem for Linux.

Voila!! That's it.


After this you can tyest which version is installed. Eg:
$ brew --version
Homebrew 2.1.16
Homebrew/homebrew-core (git revision 6176; last commit 2019-11-18)

What is Chocolatey and how to install : Step by step guide from W3LC.com about the new and cool Windows Package Manager

To start with, Chocolatey is a package manager for Windows (like apt-get or yum but for Windows). You must have also heard in past about npm as a package manager for NodeJs.
It is much like similar thing - The package manager, to be specific!

Chocolatey is a decentralized framework for quickly installing applications and tools that you need. It is built on the NuGet infrastructure.

It includes all aspects of managing Windows software (installers, zip archives, runtime binaries, internal and 3rd party software) using a packaging framework that
understands both versioning and dependency requirements.

It is open source andyYou can host your own sources and add them to Chocolatey, you can extend Chocolatey's capabilities.

How to Install Chocolatey

It's easy, you know just like grabbing a Vodka Shot. But without a hole in pocket! It's free, in case you're wondering untill now.

Steps:

1. Ensure that you are using an administrative shell.

2. Copy the text specific to your command shell.
@"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command "iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))" && SET "PATH=%PATH%;%ALLUSERSPROFILE%\chocolatey\bin"

3. Paste in shell and press Enter

4. Wait for a few seconds and let the command execute.

5. [Optional] If you are using PowerShell.exe instead of Windows command prompt, there is an additional step. You must ensure Get-ExecutionPolicy is not Restricted.

a. Run Get-ExecutionPolicy. If it returns Restricted, then run Set-ExecutionPolicy AllSigned or Set-ExecutionPolicy Bypass -Scope Process.

b. Use following command istead of the earlier mentioned in point 2.
Set-ExecutionPolicy Bypass -Scope Process -Force; iex ((New-Object System.Net.WebClient).DownloadString('https://chocolatey.org/install.ps1'))


And Voila! Its done!


References:
https://chocolatey.org/about
http://www.w3lc.com

Install and Launch Postman API Testing App in Chrome

The Postman is a post-apocalyptic science fiction novel by David Brin. Oh! come on! I am talking about Postman - The tool for Web API Testing. Postman is a Google Chrome app for interacting with HTTP APIs. It presents you with a friendly GUI for constructing requests and reading responses.

This post is related to the installation steps and way to launch the app in your browser.



1. How to Install Postman API Testing Tool. Where to get it:

Steps:
Search Google "Postman Tool". You will get the link. Or dircetly go to Chrome store at https://chrome.google.com/webstore/detail/postman/fhbjgbiflinjbdggehcddcbncdddomop?hl=en

On the RHS there is Install button. You can click that. And, it will add 'Postman' App in your browser. Once done, the button will become Green saying 'Launch App'

See below:

2. Verify if the Postman App is installed on Chrome

Steps:
Launch the extension Manager in chrome
Shortcut URL: chrome://extensions/
You can check that Postman is there.

See below:

3. How to launch Postman App in Chrome

Steps:
Launch the App launcher. You can separately install another app which acts as launcher to App
But here is a short way too. Which i personally prefer:
Go to Chrome App:
URL: chrome://apps/

See below:

Click Postman to launch it.
The App will open up.

See below:

Now enjoy ;)

CentOS 6.3 - Version/ Network/ GCC/ GDB - Settings

Good that you chose CentOS for your usage. Undoubtedly, it is a good Linux flavor. You may download latest binaries/ iso images etc from http://www.centos.org/

What is CentOS Linux?

It is worthwhile to mention that CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by a prominent North American Enterprise Linux vendor.  CentOS conforms fully with the upstream vendor's redistribution policy and aims to be 100% binary compatible. (CentOS mainly changes packages to remove upstream vendor branding and artwork.)  CentOS is free.

CentOS is developed by a small but growing team of core developers.  In turn the core developers are supported by an active user community including system administrators, network administrators, enterprise users, managers, core Linux contributors and Linux enthusiasts from around the world.

Above description may also be read in full details at centos.org.

How to check Version of CentOS? 32bit or 64 bit?

if u do uname -a

you will get linux kernel description. for eg.

Linux dnsserver 2.6.xx-yyy x86_64.

it tells you that it is a 64 bit OS

in case you want to read centos version do the following:

cat /etc/centos-release

it will return you something like "CentOS release 6.3 (final)"

Now this typically tells you that it is CentOS 6.3. Voila!!

You can also use cat /etc/redhat-release.

Install Gcc and GDB

This usually comes bundled.

In order to check version you can use --version switch. For eg.

gcc --version

gdb --version

CentOS 6.3 comes with GDB 7.2.xx series.

In case you dont have gcc etc, you can use Yum command.

First check with rpm.

Then use yum command.

For eg.

rpm -q gcc-c++

yum install gcc-c++

Network Settings in CentOS 6.3

Being a UI rich OS, you can directly set network parameters.

Goto System-->Preferences-->Network connections

Choose connection you want to correct (usually eth1 for ethernet)

Go to IpV4 setting and provide Ip address.

Press OK

Then from command shell you can check whether it is set or not. Use the command "ip a"

So, your Development or Testing infrastructure is ready. Use, code, distribute, and test your applications. And thank me too!!

Signing off for now.

Mohd Anwar Jamal Faiz

Toughjamy@yahoo.com