Monmoy042

#include "DHT.h"
#define DHTPIN 10     // DHT sensor data pin connected to the Arduino

// Definer DHT sensor type
#define DHTTYPE DHT11   // DHT 11 
//#define DHTTYPE DHT22   // DHT 22  (AM2302)
//#define DHTTYPE DHT21   // DHT 21 (AM2301)

// Initialize DHT sensor
DHT dht(DHTPIN, DHTTYPE);

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int led = 13;
void setup() {
  pinMode(led, OUTPUT);
}

void loop() {
  digitalWrite(led, HIGH);
  delay(1000);
  digitalWrite(led, LOW);
  delay(1000);

Monmoy042

Check System Information

systeminfo

Check Date

date
date /t

Check Time

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Root Password Recover in Linux System

Step-1

First we need to reboot the system.

Step-2

Secondly from the grub boot loader we need to press e from the keyboard. Here e means edit.

Step-3

Now go to end of the line number-4 and write rd.break Note: rd = rescue disk

Step-4

Then press Ctrl+X to load the system

Step-5

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Git Basic Commands

---

Git version check

$ git --version

User Name and Email Setting

$ git config --global user.email "email@example.com"
$ git config --global user.name "Mona Lisa"

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Show all network interface card(NIC) info

ip link

Interface configuration files

/etc/hostname
/etc/nsswitch.conf
/etc/resolv.conf

Monmoy042

File Archive and Compression in Linux

Arhive Utility

tar -cvf [newDirectoryName].tar [directoryName]
Exp: tar -cvf archiveEtc.tar etc

Extract Archived Directory

tar -xvf [archivedDirectoryName]

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VIM Editor

VIM is a terminal based text editor. It is very handy to use. This is the most powerful text editor that by default comes with almost all Unix/Linux system.

Basic guide of VIM editor has given below:

VIM Editor Basic Commands

Insert Mode --> Command = (i)
Escape Mode --> Command = (Esc)
File save and quit --> Command = (:x)

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File permission & ownership in Linux

File permission and ownership is very important in linux system.

Types of file/directory in Linux System

1. (-) = regular file : text/js//html/css/any file
2. (d) = directory : regular directory
3. (l) = link file : ls -l /dev/stdin
4. (b) = block devices : ls -l /dev/sda --> (CD/DVD/HDD/ISO/USB)
5. (s) = socket : ls -l /sun/rpcbind.sock
6. (p) = pipe file : ls -l /run/initctl

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Linux User & Group Administration

There are three types of user we can see in the linux system
1) root : 0
2) System User : 1-999
3) Regular user: 1000+

Show all the user info