Obie  Rowe

Obie Rowe

1592819160

Comment installer Node.js sur Ubuntu 20.04

Node.js est un runtime JavaScript pour la programmation côté serveur. Il permet aux développeurs de créer des fonctionnalités d’arrière-plan évolutives en utilisant JavaScript, un langage que beaucoup connaissent déjà grâce au développement web par navigateur.

Dans ce guide, nous vous montrerons trois façons différentes d’installer Node.js sur un serveur Ubuntu 20.04 :

en utilisant apt pour installer le paquet nodejs à partir du dépôt de logiciels par défaut d’Ubuntu
en utilisant apt avec un autre dépôt de logiciels PPA pour installer des versions spécifiques du paquet nodejs
en installant nvm, le gestionnaire de versions des nœuds, et en l’utilisant pour installer et gérer plusieurs versions de Node.js

#ubuntu 20.04 #ubuntu

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Buddha Community

Comment installer Node.js sur Ubuntu 20.04

NBB: Ad-hoc CLJS Scripting on Node.js

Nbb

Not babashka. Node.js babashka!?

Ad-hoc CLJS scripting on Node.js.

Status

Experimental. Please report issues here.

Goals and features

Nbb's main goal is to make it easy to get started with ad hoc CLJS scripting on Node.js.

Additional goals and features are:

  • Fast startup without relying on a custom version of Node.js.
  • Small artifact (current size is around 1.2MB).
  • First class macros.
  • Support building small TUI apps using Reagent.
  • Complement babashka with libraries from the Node.js ecosystem.

Requirements

Nbb requires Node.js v12 or newer.

How does this tool work?

CLJS code is evaluated through SCI, the same interpreter that powers babashka. Because SCI works with advanced compilation, the bundle size, especially when combined with other dependencies, is smaller than what you get with self-hosted CLJS. That makes startup faster. The trade-off is that execution is less performant and that only a subset of CLJS is available (e.g. no deftype, yet).

Usage

Install nbb from NPM:

$ npm install nbb -g

Omit -g for a local install.

Try out an expression:

$ nbb -e '(+ 1 2 3)'
6

And then install some other NPM libraries to use in the script. E.g.:

$ npm install csv-parse shelljs zx

Create a script which uses the NPM libraries:

(ns script
  (:require ["csv-parse/lib/sync$default" :as csv-parse]
            ["fs" :as fs]
            ["path" :as path]
            ["shelljs$default" :as sh]
            ["term-size$default" :as term-size]
            ["zx$default" :as zx]
            ["zx$fs" :as zxfs]
            [nbb.core :refer [*file*]]))

(prn (path/resolve "."))

(prn (term-size))

(println (count (str (fs/readFileSync *file*))))

(prn (sh/ls "."))

(prn (csv-parse "foo,bar"))

(prn (zxfs/existsSync *file*))

(zx/$ #js ["ls"])

Call the script:

$ nbb script.cljs
"/private/tmp/test-script"
#js {:columns 216, :rows 47}
510
#js ["node_modules" "package-lock.json" "package.json" "script.cljs"]
#js [#js ["foo" "bar"]]
true
$ ls
node_modules
package-lock.json
package.json
script.cljs

Macros

Nbb has first class support for macros: you can define them right inside your .cljs file, like you are used to from JVM Clojure. Consider the plet macro to make working with promises more palatable:

(defmacro plet
  [bindings & body]
  (let [binding-pairs (reverse (partition 2 bindings))
        body (cons 'do body)]
    (reduce (fn [body [sym expr]]
              (let [expr (list '.resolve 'js/Promise expr)]
                (list '.then expr (list 'clojure.core/fn (vector sym)
                                        body))))
            body
            binding-pairs)))

Using this macro we can look async code more like sync code. Consider this puppeteer example:

(-> (.launch puppeteer)
      (.then (fn [browser]
               (-> (.newPage browser)
                   (.then (fn [page]
                            (-> (.goto page "https://clojure.org")
                                (.then #(.screenshot page #js{:path "screenshot.png"}))
                                (.catch #(js/console.log %))
                                (.then #(.close browser)))))))))

Using plet this becomes:

(plet [browser (.launch puppeteer)
       page (.newPage browser)
       _ (.goto page "https://clojure.org")
       _ (-> (.screenshot page #js{:path "screenshot.png"})
             (.catch #(js/console.log %)))]
      (.close browser))

See the puppeteer example for the full code.

Since v0.0.36, nbb includes promesa which is a library to deal with promises. The above plet macro is similar to promesa.core/let.

Startup time

$ time nbb -e '(+ 1 2 3)'
6
nbb -e '(+ 1 2 3)'   0.17s  user 0.02s system 109% cpu 0.168 total

The baseline startup time for a script is about 170ms seconds on my laptop. When invoked via npx this adds another 300ms or so, so for faster startup, either use a globally installed nbb or use $(npm bin)/nbb script.cljs to bypass npx.

Dependencies

NPM dependencies

Nbb does not depend on any NPM dependencies. All NPM libraries loaded by a script are resolved relative to that script. When using the Reagent module, React is resolved in the same way as any other NPM library.

Classpath

To load .cljs files from local paths or dependencies, you can use the --classpath argument. The current dir is added to the classpath automatically. So if there is a file foo/bar.cljs relative to your current dir, then you can load it via (:require [foo.bar :as fb]). Note that nbb uses the same naming conventions for namespaces and directories as other Clojure tools: foo-bar in the namespace name becomes foo_bar in the directory name.

To load dependencies from the Clojure ecosystem, you can use the Clojure CLI or babashka to download them and produce a classpath:

$ classpath="$(clojure -A:nbb -Spath -Sdeps '{:aliases {:nbb {:replace-deps {com.github.seancorfield/honeysql {:git/tag "v2.0.0-rc5" :git/sha "01c3a55"}}}}}')"

and then feed it to the --classpath argument:

$ nbb --classpath "$classpath" -e "(require '[honey.sql :as sql]) (sql/format {:select :foo :from :bar :where [:= :baz 2]})"
["SELECT foo FROM bar WHERE baz = ?" 2]

Currently nbb only reads from directories, not jar files, so you are encouraged to use git libs. Support for .jar files will be added later.

Current file

The name of the file that is currently being executed is available via nbb.core/*file* or on the metadata of vars:

(ns foo
  (:require [nbb.core :refer [*file*]]))

(prn *file*) ;; "/private/tmp/foo.cljs"

(defn f [])
(prn (:file (meta #'f))) ;; "/private/tmp/foo.cljs"

Reagent

Nbb includes reagent.core which will be lazily loaded when required. You can use this together with ink to create a TUI application:

$ npm install ink

ink-demo.cljs:

(ns ink-demo
  (:require ["ink" :refer [render Text]]
            [reagent.core :as r]))

(defonce state (r/atom 0))

(doseq [n (range 1 11)]
  (js/setTimeout #(swap! state inc) (* n 500)))

(defn hello []
  [:> Text {:color "green"} "Hello, world! " @state])

(render (r/as-element [hello]))

Promesa

Working with callbacks and promises can become tedious. Since nbb v0.0.36 the promesa.core namespace is included with the let and do! macros. An example:

(ns prom
  (:require [promesa.core :as p]))

(defn sleep [ms]
  (js/Promise.
   (fn [resolve _]
     (js/setTimeout resolve ms))))

(defn do-stuff
  []
  (p/do!
   (println "Doing stuff which takes a while")
   (sleep 1000)
   1))

(p/let [a (do-stuff)
        b (inc a)
        c (do-stuff)
        d (+ b c)]
  (prn d))
$ nbb prom.cljs
Doing stuff which takes a while
Doing stuff which takes a while
3

Also see API docs.

Js-interop

Since nbb v0.0.75 applied-science/js-interop is available:

(ns example
  (:require [applied-science.js-interop :as j]))

(def o (j/lit {:a 1 :b 2 :c {:d 1}}))

(prn (j/select-keys o [:a :b])) ;; #js {:a 1, :b 2}
(prn (j/get-in o [:c :d])) ;; 1

Most of this library is supported in nbb, except the following:

  • destructuring using :syms
  • property access using .-x notation. In nbb, you must use keywords.

See the example of what is currently supported.

Examples

See the examples directory for small examples.

Also check out these projects built with nbb:

API

See API documentation.

Migrating to shadow-cljs

See this gist on how to convert an nbb script or project to shadow-cljs.

Build

Prequisites:

  • babashka >= 0.4.0
  • Clojure CLI >= 1.10.3.933
  • Node.js 16.5.0 (lower version may work, but this is the one I used to build)

To build:

  • Clone and cd into this repo
  • bb release

Run bb tasks for more project-related tasks.

Download Details:
Author: borkdude
Download Link: Download The Source Code
Official Website: https://github.com/borkdude/nbb 
License: EPL-1.0

#node #javascript

Chet  Lubowitz

Chet Lubowitz

1595429220

How to Install Microsoft Teams on Ubuntu 20.04

Microsoft Teams is a communication platform used for Chat, Calling, Meetings, and Collaboration. Generally, it is used by companies and individuals working on projects. However, Microsoft Teams is available for macOS, Windows, and Linux operating systems available now.

In this tutorial, we will show you how to install Microsoft Teams on Ubuntu 20.04 machine. By default, Microsoft Teams package is not available in the Ubuntu default repository. However we will show you 2 methods to install Teams by downloading the Debian package from their official website, or by adding the Microsoft repository.

Install Microsoft Teams on Ubuntu 20.04

1./ Install Microsoft Teams using Debian installer file

01- First, navigate to teams app downloads page and grab the Debian binary installer. You can simply obtain the URL and pull the binary using wget;

$ VERSION=1.3.00.5153
$ wget https://packages.microsoft.com/repos/ms-teams/pool/main/t/teams/teams_${VERSION}_amd64.deb

#linux #ubuntu #install microsoft teams on ubuntu #install teams ubuntu #microsoft teams #teams #teams download ubuntu #teams install ubuntu #ubuntu install microsoft teams #uninstall teams ubuntu

Servo Node

Servo Node

1626801695

Install VirtualBox in Ubuntu 21.04/20.04/18.04 › Servo Node

VirtualBox is a widely known and open-source tool offered by Oracle. It’s a cross platform virtualization application that can be installed on any system that allows users to run a number of guest operating systems on single machine over a virtual system.

Means, with the usage of VirtualBox on your system, you can easily install many operating systems and can run them simultaneously which can be helpful to develop, demonstrate, deploy and test applications on a single machine.

How to install VirtualBox On Ubuntu 18.04, 20.04 and 21.04?

Since the virtualization system offered by Oracle is available for cross platforms, even Ubuntu users can install the app and take its benefits. In order to install VirtualBox in Ubuntu variants, there’s a number of approaches that can be helpful.

Installing using default repository

sudo apt install virtualbox

Install using official DEB package

Visit the Virtualbox download page and download DEB package in your machine, and run the following command to install the package using ATP command.

sudo apt install ./virtualbox-6.1_6.1.22-144080_Ubuntu_bionic_amd64.deb

for more approaches and information, Read Here

#install virtual box on ubuntu #install virtual box on ubuntu 18.04 #install virtual box on ubuntu 20.04 #install virtual box on ubuntu21.04

Arvel  Parker

Arvel Parker

1592209410

How to Install PgAdmin 4 on Ubuntu 20.04

pgAdmin is the leading graphical Open Source management, development and administration tool for PostgreSQL. pgAdmin4 is a rewrite of the popular pgAdmin3 management tool for the PostgreSQL database.

In this tutorial, we are going to show you how to install pgAdmin4 in Server Mode as a web application using apache2 and Wsgi module on Ubuntu 20.04 LTS.

#databases #linux #ubuntu #install pgadmin4 #install pgadmin4 ubuntu #install pgadmin4 ubuntu 20 #pgadmin4 #ubuntu pgadmin4 #ubuntu pgadmin4 install

Chet  Lubowitz

Chet Lubowitz

1595515560

How to Install TeamViewer on Ubuntu 20.04

TeamViewer is a cross-platform, proprietary application that allows a user to remotely connect to a workstation, transfer files, and have online meetings. In this tutorial, we will walk you through how to install TeamViewer on Ubuntu 20.04 Desktop through the command line.

Prerequisites

Before continuing with this tutorial, make sure you are logged in as a user with sudo privileges.

Installing TeamViewer on Ubuntu

01- To install TeamViewer, first, download the TeamViewer .deb package. So, open the Terminal and run the following wget command.

$ wget https://download.teamviewer.com/download/linux/teamviewer_amd64.deb

02- Once you have downloaded the TeamViewer‘s Debian package, execute the following command to install Teamviewer:

$ sudo apt install ./teamviewer_amd64.deb

The system will prompt you with a [Y/n] option. Type ‘Y‘ and hit the enter key in order for to continue the installation.

03- Once the installation is done, you can launch TeamViewer either by typing the command teamviewer in your terminal or by clicking on the TeamViewer icon (Activities -> TeamViewer).

04- A pop-up License Agreement will be displayed. To proceed, click on the Accept License Agreement button.

#linux #ubuntu #install teamviewer #install teamviewer ubuntu #teamviewer #teamviewer ubuntu #teamviewer ubuntu install #ubuntu install teamviewer