Merge branch 'master' of github.com:LeCoupa/awesome-cheatsheets

README.md

@@ -28,6 +28,7 @@ Feel free to take a look. You might learn new things. They have been designed to
 - [C](languages/C.txt)
 - [C#](languages/C%23.txt)
 - [PHP](languages/php.php)
+- [JAVA](languages/java.md)
 
 #### Functional
 
@@ -98,6 +99,7 @@ Feel free to take a look. You might learn new things. They have been designed to
 #### Development
 
 - [cURL](tools/curl.sh)
+- [Drush](tools/drush.sh)
 - [Elasticsearch](tools/elasticsearch.js)
 - [Emmet](tools/emmet.md)
 - [Git](tools/git.sh)

databases/mysql.sh

@@ -7,4 +7,20 @@ mysql -u username -p database_name < file.sql                         # Import d
 
 SHOW PROCESSLIST; # Show you any queries that are currently running or in the queue to run
 
-GRANT ALL ON mydb.* TO 'myuser'@'locahost'; # Grant **all** privileges on database
+# *****************************************************************************
+# Users and Privileges
+# *****************************************************************************
+
+# Replace 'host' with '%' to indicate any host
+
+CREATE USER 'user'@'host'; # Create user
+DROP USER 'user'@'host'; # Remove user.
+
+GRANT ALL PRIVILEGES ON base.* TO 'user'@'host' IDENTIFIED BY 'password'; # Grant access to database using password
+GRANT SELECT, INSERT, DELETE ON base.* TO 'user'@'host' IDENTIFIED BY 'password'; # Grant specific privileges to database using password
+GRANT ALL PRIVILEGES ON base.* TO 'user'@'host' WITH GRANT OPTION; # Grant **all** privileges on database
+
+REVOKE ALL PRIVILEGES ON base.* FROM 'user'@'host'; # Remove privileges on database
+REVOKE ALL PRIVILEGES, GRANT OPTION FROM 'user'@'host'; # Remove **all** privileges on database
+
+FLUSH PRIVILEGES; # Use **only** if you modify grant tables directly using statements like INSERT, UPDATE or DELETE.

frontend/html5.html

@@ -45,6 +45,11 @@
 <abbr></abbr>                                     <!-- Contains abbreviations while also making the full form avaialable -->
 <address></address>                               <!-- Used to display contact information -->
 <code></code>                                     <!-- Used to display inline code snippets -->
+<q></q>                                           <!-- Defines a short inline quotation -->
+<sub></sub>                                       <!-- 	Defines subscripted text -->
+<sup></sup>                                       <!-- Defines superscripted text -->
+<kbd></kbd>                                       <!-- Specifies text as keyboard input -->
+<small></small>                                   <!-- Specifies small text -->  
 
 
 <!-- Links Formatting -->
@@ -176,6 +181,11 @@ width=""                                          <!-- Describes the width of th
 <time></time>                                     <!-- Identifies the time and date -->
 <wbr>                                             <!-- A line break within the content -->
 
+<!-- Some other useful tags -->
+
+<canvas></canvas>                                 <!-- Allows to draw 2D shapes on the web page with the help of javascript -->
+<keygen>                                          <!-- Represents a control for generating a public-private key pair -->
+<map></map>                                       <!-- Specifies an image map -->
 
 <!-- Collective Character Obejcts -->
 

languages/bash.sh

@@ -95,6 +95,8 @@ genscript                     # converts plain text files into postscript for pr
 dvips <filename>              # prints .dvi files (i.e. files produced by LaTeX)
 grep <pattern> <filenames>    # looks for the string in the files
 grep -r <pattern> <dir>       # search recursively for pattern in directory
+head -n file_name | tail +n   # Print nth line from file.
+head -y lines.txt | tail +x   # want to display all the lines from x to y. This includes the xth and yth lines.
 
 
 ##############################################################################
@@ -111,7 +113,7 @@ cd ..                         # changes to the parent directory
 cd <dirname>                  # changes directory
 cp -r <dir1> <dir2>           # copy <dir1> into <dir2> including sub-directories
 pwd                           # tells you where you currently are
-
+cd ~                          # changes to home.
 
 ##############################################################################
 # SSH, SYSTEM INFO & NETWORK COMMANDS

languages/java.md

@@ -0,0 +1,619 @@
+### HELLO WORLD :ghost:
+
+```java
+//Text file name HelloWorld.java
+public class HelloWorld {
+  // main() is the method
+  public static void main (String[] arfs)
+    //Prints "Hello World" in the terminal window.
+    System.out.pritn("Hello World");
+}
+```
+
+### COMPILATION & EXECUTING JAVA CODE
+
+* Goto your program directory in terminal (Assumed JAVA Path is set)
+* After for compile your code
+
+> **javac HelloWorld.java (your program file name)**
+  
+* For run program 
+
+> **java HelloWorld (main class name)**
+
+
+### DATA TYPES
+
+|   Type  |      Set of values      |            Values            | Operators |
+|:-------:|:-----------------------:|:----------------------------:|:---------:|
+|   int   |         integers        | between -2^31 and + (2^31)-1 | + - * / % |
+|  double |  floating-point numbers |         real numbers         |  + - * /  |
+| boolean |      boolean values     |         true or false        | && \|\| ! |
+|   char  |        characters       |                              |           |
+|  String | sequences of characters |                              |           |
+
+
+### DECLARATION AND ASSIGNMENT STATEMENTS
+
+```java
+//Declaration statement
+int a,b;
+
+//Assignment statement
+a = 13212; //a is the variable name; 13212 is the literal which is assign to the variable a
+
+//Initialization statement
+int c = a + b;
+```
+
+### COMPARISON OPERATORS
+
+| Operation |        Meaning        |
+|:---------:|:---------------------:|
+|     ==    |         equal         |
+|     !=    |       not equal       |
+|     <     |       less than       |
+|     >     |      greater than     |
+|     <=    |   less than or equal  |
+|     >=    | greater than or equal |
+
+
+### PRINTING
+```java
+  String s = "Happy Coding Folks!!"
+  void System.out.print(String s) //print s
+  void System.out.println(String s) //print s, followed by a newline
+  void System.out.println() //print a newline
+```
+
+### PARSING COMMAND-LINE ARGUMENTS
+```java 
+  String s = "Java is the best!!"
+  int Integer.parseInt(String s) //convert s to an int value
+  double Double.parseDouble(String) //convert s to a double value
+  long Long.parseLong(String s) // convert s to a long value
+````
+
+### MATH LIBRARY
+```java
+  Public Class Math{
+    double abs(double a)    // absolute value of a
+    double max(double a, double b)  //maximum of a and b
+    double min(double a, dobule a)  //minimum of a and b
+    double sin(double theta) //sine of theta
+    double cos(double theta) //cosine of theta
+    double tan(double theta) //tangent of theta
+    double toRadians(double degrees) // convert angle from degrees to radians
+    double toDegreestouble radians)  // convert angle from radians to degrees
+    double exp(doube a)  // exponential (e^a)
+    double pow(double a, double p) //raise a to the bth power (a^b)
+    double random() //random in [0,1)
+    double sqrt(double a)  //square root of a
+    }
+```
+
+### EXAMPLES OF TYPE CONVERSION
+
+  |       Expression      | Expression type | Expression value |
+|:---------------------:|:---------------:|:----------------:|
+| (1 + 2 + 3 + 4) / 4.0 |      double     |        2.5       |
+|      Math.sqrt(4)     |      double     |        2.0       |
+|     "123343" + 99     |      String     |    "12334399"    |
+|       11 * 0.25       |      double     |       2.75       |
+|    (int) 11 * 0.25    |      double     |       2.75       |
+|    11 * (int) 0.25    |       int       |         0        |
+|   (int) (11 * 0.25)   |       int       |         2        |
+
+### CONDITIONAL & LOOP STATEMENT
+#### ANATOMY OF CONDITIONAL STATEMENT
+> IF Statement
+```java
+  if (x>y) { // x > y is the boolean expression
+   //Sequence of statements
+   x = y;
+  } 
+```
+
+> IF-ELSE STATEMENT
+```java
+   if (BOOLEAN EXPRESSION) { 
+   //Sequence of statements
+   } else {
+   //Sequence of statements
+   }
+```
+
+> NESTED IF STATEMENT
+```java
+   if (BOOLEAN EXPRESSION) { 
+   //Sequence of statements
+   } else if {
+   //Sequence of statements
+   }
+   .
+   .
+   .
+   else {
+   //Sequence of statements
+   }
+```
+
+>SWITCH STATEMENT
+```java
+  switch (VARIABLE TO EVALUATE ITS VALUE) {
+    case value: Statement; break;
+    ...
+    ...
+    ...
+    default: Statement; break;
+  }
+```
+**Example:**
+```java
+  int month = 8;
+        String monthString;
+        switch (month) {
+            case 1:  monthString = "January";
+                     break;
+            case 2:  monthString = "February";
+                     break;
+            case 3:  monthString = "March";
+                     break;
+            case 4:  monthString = "April";
+                     break;
+            case 5:  monthString = "May";
+                     break;
+            case 6:  monthString = "June";
+                     break;
+            case 7:  monthString = "July";
+                     break;
+            case 8:  monthString = "August";
+                     break;
+            case 9:  monthString = "September";
+                     break;
+            case 10: monthString = "October";
+                     break;
+            case 11: monthString = "November";
+                     break;
+            case 12: monthString = "December";
+                     break;
+            default: monthString = "Invalid month";
+                     break;
+        }
+```
+
+#### ANATOMY OF A LOOP  STATEMENT
+>FOR LOOP STATEMENT
+```java
+  for (declare and initialize a loop control variable; loop-continuation condition/s; increment or decrement of the variable of control)
+  {
+    //Statement
+  }
+``` 
+**Example:**
+```java  
+  for (int i = 0; i <= n; i++) {
+     System.out.println(i);
+  }
+```
+> WHILE LOOP STATEMENT
+```java
+    while(condition){  //till condition will be true.
+    //code to be executed 
+    }
+```
+**Example:**
+```java
+  //Initialization is a separate statement
+  int power = 1;
+
+  while ( power <= 10/2 ) // power <= n/2 is an example of the loop-continuation condition
+  {
+    System.out.println(power);
+  }
+```
+
+> DO-WHILE LOOP STATEMENT
+
+```java
+  do{ //always run one time even if condition would be false
+    //Statement
+  } while(loop-continuation condition);
+```
+
+**Example:**
+```java
+    int i=1;  
+    do{  
+      System.out.println(i);  
+      i++;  
+    }while(i<=10); 
+```
+
+### ARRAY
+> ARRAY DECLARATION
+
+```java
+    int[]           ai;        // array of int
+    short[][]       as;        // array of array of short
+    short           s,         // scalar short
+                    aas[][];   // array of array of short
+    Object[]        ao;        // array of Object
+    Collection<?>[] ca;  // array of Collection of unknown type
+```
+
+> DECLARATION OF ARRAY VARIABLE
+
+```java
+  Exception ae[]  = new Exception[3];
+  Object aao[][]  = new Exception[2][3];
+  int[] factorial = { 1, 1, 2, 6, 24, 120, 720, 5040 };
+  char ac[]       = { 'n', 'o', 't', ' ', 'a', ' ',
+                      'S', 't', 'r', 'i', 'n', 'g' };
+  String[] aas    = { "array", "of", "String", };
+```
+
+### ACCESS MODIFIERS
+
+1. defualt(No keyword required) 
+2. private
+3. public
+4. protected 
+
+### NON ACCESS MODIFIERS
+
+1. static 
+2. final 
+3. transient
+4. abstract
+5. synchronized
+6. volatile 
+
+## Object Oriented Programming (OOPs) Concept :clipboard:
+
+### OBJECT
+
+```java
+  //Declare a variable, object name
+  String s;
+
+  //Invoke a contructor to create an object
+  s = new String ("Hello World");
+
+  //Invoke an instance method that operates on the object's value
+  char c = s.chartAt(4);
+```
+> INSTANCE VARIABLES
+
+```java
+  public class Charge {
+    //Instance variable declarations
+    private final double rx, ry;
+    private final double q;
+  }
+```
+
+### METHODS
+
+```java
+  public static double sum (int a, int b) { //double is the return type, sum is the method's name, a and b are two arguments of type int;
+    int result; //local variable
+    result = a + b;
+    return result;//return statement;
+  }
+```
+
+### CLASS DECLARATION
+```java
+class MyClass {
+    // field, constructor, and 
+    // method declarations
+}
+```
+**Example:**
+
+```java
+    public class Bicycle {
+        // the Bicycle class has
+        // three fields
+        public int cadence;
+        public int gear;
+        public int speed;
+        // the Bicycle class has
+        // one constructor
+        public Bicycle(int startCadence, int startSpeed, int startGear) {
+            gear = startGear;
+            cadence = startCadence;
+            speed = startSpeed;
+        }
+        // the Bicycle class has
+        // four methods
+        public void setCadence(int newValue) {
+            cadence = newValue;
+        }   
+        public void setGear(int newValue) {
+            gear = newValue;
+        }   
+        public void applyBrake(int decrement) {
+            speed -= decrement;
+        }  
+        public void speedUp(int increment) {
+            speed += increment;
+        }
+}
+```
+>DECLARING CLASSESS IMPLEMENTATING AN INTERFACE AND EXTENDING PARENT CLASS
+```java
+class MyClass extends MySuperClass implements YourInterface {
+    // field, constructor, and
+    // method declarations
+}
+```
+* MyClass is a subclass of MySuperClass and that it implements the YourInterface interface.
+
+> CONSTRUCTORS
+* A class contains constructors that are invoked to create objects from the class blueprint.
+* Constructor declarations look like method declarations—except that they use the name of the class and have no return type
+* Each and every class has defualt No-args constructor.
+
+
+```java
+  public class Bicycle{
+      
+      private int gear;
+      private int cadence;
+      private int speed;
+     
+      public Bicycle(int startCadence, int startSpeed, int startGear) { //args-constructor
+        gear = startGear;
+        cadence = startCadence;
+        speed = startSpeed;
+      }
+
+      public Bicycle(){//No-args constructor
+        super();
+      }
+  }
+```
+
+### POLYMORPHISM
+* Polymorphism is the concept where an object behaves differently in different situations.
+*  There are two types of polymorphism 
+    1. compile time polymorphism 
+    2. runtime polymorphism.
+
+#### 1. Compile Time Polymorphism
+* Compile-time polymorphism is achieved by method overloading.
+* method overloading is creating multiple method with methods name is same and arguments are different. 
+```java
+  public class Circle {
+
+    public void draw(){
+      System.out.println("Drwaing circle with default color Black and diameter 1 cm.");
+    }
+
+    public void draw(int diameter){ //method draw() overloaded.
+      System.out.println("Drwaing circle with default color Black and diameter"+diameter+" cm.");
+    }
+
+    public void draw(int diameter, String color){ //method draw() overloaded.
+      System.out.println("Drwaing circle with color"+color+" and diameter"+diameter+" cm.");
+    }
+  }
+```
+#### 2. Run Time Polymorphism
+* Run-time polymorphism is achieved by method overriding.
+* Runtime polymorphism is implemented when we have an **“IS-A”** relationship between objects.
+* method overriding is the subclass has to override the superclass method.
+```java
+    public interface Shape {
+
+	    public void draw();
+    }
+```
+```java
+    public class Circle implements Shape{
+
+      @Override
+      public void draw(){
+        System.out.println("Drwaing circle");
+      }
+
+    }
+```
+```java
+    public class Square implements Shape {
+
+      @Override
+      public void draw() {
+        System.out.println("Drawing Square");
+      }
+
+    }
+```
+* `Shape` is the superclass and there are two subclasses `Circle` and `Square`
+* Below is an example of runtime polymorphism.
+```java
+    Shape sh = new Circle();
+    sh.draw();
+
+    Shape sh1 = getShape(); //some third party logic to determine shape
+    sh1.draw();
+```
+
+### INHERITANCE
+
+* Inheritance is the mechanism of code reuse. 
+* The object that is getting inherited is called the superclass and the object that inherits the superclass is called a subclass.
+* We use `extends` keyword in java to implement inheritance from class.
+* We use `implements` keyword in java to implement inheritance from interface.
+
+```java
+    public class Superclass{
+      // methods and fields
+    }
+```
+```java
+    public interface Superinterface{
+      // methods and fields
+    }
+```
+```java
+    public class Subclass extends Superclass implements Superinterface{
+      // methods and fields
+    }
+```
+
+### Abstraction
+
+* Abstraction is the concept of hiding the internal details and describing things in simple terms.
+* Abstraction can be achieved by two ways.
+  1. Abstract Class
+  2. Interface
+  
+#### 1. Abstract Class
+* An abstract class must be declared with an `abstract` keyword.
+* It can have abstract and non-abstract methods.
+* It cannot be instantiated.
+* It can have constructors and static methods also.
+* It can have final methods which will force the subclass not to change the body of the method.
+
+```java
+    abstract class Flower{
+        abstract String Smell(); //abstract method.
+        String Oil(){  // non-abstract method. 
+           System.out.println("Flower Oil is good.");
+         }
+    }
+
+    public class Lily extends Flower{
+        private String Smell(){ // implementation of abstarct method.
+          System.out.println("Lily smell's lovender.");
+        }
+    }
+```
+
+#### 2. Interface
+* Interface is a blueprint of a **class**.
+* It can have only abstract methods. [Except Java 8 and next versions.]
+* Since Java 8, we can have **default and static** methods in an interface.
+
+
+```java
+    interface print{  
+        void printPaper();  
+    }  
+    public class A4 implements print{  
+        public void printPaper(){
+          System.out.println("A4 Page Printed. ");
+        }  
+    }
+```
+
+### Encapsulation
+
+* Encapsulation is used for access restriction to class members and methods.
+* Encapsulation is the technique used to implement abstraction in OOP.
+* As in encapsulation, the data in a class is hidden from other classes, so it is also known as **data-hiding**.
+* Encapsulation can be achieved by Declaring all the variables in the class as private and writing public methods in the class to set and get the values of variables.
+* Best example of Encapsulation is POJO (Plain-Java-Object-Class).
+  
+ ```java
+    public class User {
+        private String username;
+        private String password;
+
+        public String getUsername() {
+          return username;
+        }
+
+        public void setUsername(String username) {
+          this.username = username;
+        }
+
+        public String getPassword() {
+          return password;
+        }
+
+        public void setPassword(String password) {
+          this.password = password;
+        }
+    }
+ ```
+  
+
+## ADVANCE DATA TYPE
+* **STACK DATA TYPE**
+
+```java
+  public class Stack<Item> implements Iterable <Item>
+
+  Stack()   //create an empty stack
+  boolean isEmpty() //return if the stack empty
+  void push(Item item) // push an item onto the stack
+  Item pop() //return and remove the item that was inserted most recently
+  int size() //number of item on stack
+```
+
+* **QUEUE DATA TYPE**
+
+```java
+  public class Queue<Item> implements Iterable<Item>
+
+  Queue()  //create an emptyh queue
+  boolean isEmpthy()  //return if the queue empthy
+  void enqueue(Item item) // insert an item onto queue
+  Item dequeue()  //return and remove the item that was inserted least recently
+  int size() //number of item on queue
+```
+
+* **ITERABLE**
+
+```java
+//import Iterator
+import java.util.Iterator;
+
+public class Queue<Item> implements Iterable <Item> { 
+
+//FIFO queue
+  private Node first;
+  private Node last;
+  private class Node {
+    Item item;
+    Node next;
+  }
+
+  public void enqueue (Item item)
+  ...
+
+  public Item dequeue()
+  ...
+
+}
+```
+
+* **SYMBOL TABLE DATA TYPE**
+
+```java
+  public class ST<Key extends Comparable<Key>, Value>
+
+  ST()  //create and empty symbol table
+  void put(Key key, Value val)  //associate val with key
+  Value get(Key key)  //value associated with key
+  void remove(Key key) //remove key (and its associated value)
+  boolean contains (Key key)  //return if there is a value associated with key
+  int size()  //number of key-value pairs
+  Iterable<Key> keys()  // all keys in the symbol table
+```
+
+* **SET DATA TYPE**
+
+```java
+  public class SET<Key extends Comparable<Key>> implements Iterable<Key>
+  SET() //create an empthy set
+  boolean isEmpthy()  //return if the set is empthy
+  void add (Key key)  //add key to the set
+  void remove(Key key)  //remove key from set
+  boolean contains(Key key) //return if the key is in the set
+  int size() //number of elements in set
+```

languages/php.php

@@ -366,3 +366,106 @@ class ClassWithLogger
      */
     use LoggerAwareTrait;
 }
+
+
+/**
+ * PHP Regex.
+ */
+
+// Meta Characters.
+
+^   Start of subject (or line in multiline mode)
+$   End of subject (or line in multiline mode)
+[   Start character class definition
+]   End character class definition
+|   Alternates, eg (a|b) matches a or b
+(   Start subpattern
+)   End subpattern
+\   Escape character
+
+// Pattern Modifiers.
+
+i   Caseless - ignore case
+m   Multiline mode - ^ and $ match start and end of lines
+s   Dotall - . class includes newline
+x   Extended- comments & whitespace
+e   preg_replace only - enables evaluation of replacement as PHP code
+S   Extra analysis of pattern
+U   Pattern is ungreedy
+u   Pattern is treated as UTF-8
+
+// Subpattern Modifiers & Assertions.
+(?:)    Non capturing subpattern    ((?:foo|fu)bar) matches foobar or fubar without foo or fu appearing as a captured subpattern
+(?=)    Positive look ahead assertion   foo(?=bar) matches foo when followed by bar
+(?!)    Negative look ahead assertion   foo(?!bar) matches foo when not followed by bar
+(?<=)   Positive look behind assertion  (?<=foo)bar matches bar when preceded by foo
+(?<!)   Negative look behind assertion  (?<!foo)bar matches bar when not preceded by foo
+(?>)    Once-only subpatterns   (?>\d+)bar Performance enhancing when bar not present
+(?(x))  Conditional subpatterns (?(3)foo|fu)bar Matches foo if 3rd subpattern has matched, fu if not
+(?#)    Comment (?# Pattern does x y or z)
+
+// Base Character Classes
+\w  Any "word" character (a-z 0-9 _)
+\W  Any non "word" character
+\s  Whitespace (space, tab CRLF)
+\S  Any non whitepsace character
+\d  Digits (0-9)
+\D  Any non digit character
+.   (Period) - Any character except newline
+
+// Multiplicity.
+n*  Zero or more of n
+n+  One or more of n
+n?  Zero or one occurrences of n
+{n} n occurrences exactly
+{n,}    At least n occurrences
+{,m}    At most m occurrences
+{n,m}   Between n and m occurrences (inclusive)
+
+
+// PHP Regular Expression Functions.
+
+Function    Description
+preg_match()    The preg_match() function searches string for pattern, returning true if pattern exists, and false otherwise.
+preg_match_all()    The preg_match_all() function matches all occurrences of pattern in string. Useful for search and replace.
+preg_replace()  The preg_replace() function operates just like ereg_replace(), except that regular expressions can be used in the pattern and replacement input parameters.
+preg_split()    Preg Split (preg_split()) operates exactly like the split() function, except that regular expressions are accepted as input parameters.
+preg_grep() The preg_grep() function searches all elements of input_array, returning all elements matching the regex pattern within a string.
+preg_ quote()   Quote regular expression characters
+
+// Code Snippets.
+
+//A better solution for validate email syntax is using filter_var.
+if (filter_var('test+email@fexample.com', FILTER_VALIDATE_EMAIL)) {
+    echo "Your email is ok.";
+} else {
+    echo "Wrong email address format.";
+}
+
+//Validate username, consist of alpha-numeric (a-z, A-Z, 0-9), underscores, and has minimum 5 character and maximum 20 character.
+//You could change the minimum character and maximum character to any number you like.
+$username = "user_name12";
+if (preg_match('/^[a-z\d_]{5,20}$/i', $username)) {
+    echo "Your username is ok.";
+} else {
+    echo "Wrong username format.";
+}
+
+//Validate domain
+$url = "http://domain-name.com/";
+if (preg_match('/^(http|https|ftp):\/\/([A-Z0-9][A-Z0-9_-]*(?:\.[A-Z0-9][A-Z0-9_-]*)+):?(\d+)?\/?/i', $url)) {
+    echo "Your url is ok.";
+} else {
+    echo "Wrong url.";
+}
+
+//Extract domain name from certain URL
+$url = "http://domain-name.com/index.html";
+preg_match('@^(?:http://)?([^/]+)@i', $url, $matches);
+$host = $matches[1];
+echo $host; // domain-name.com
+
+//Highlight a word in the content
+$text = "A regular expression (shortened as regex) is a sequence of characters that define a search pattern. Usually such patterns are used by string-searching algorithms for 'find' or 'find and replace' operations on strings, or for input validation.";
+$text = preg_replace("/\b(regex)\b/i", 'replaced content', $text);
+echo $text; /*A regular expression (shortened as replaced content) is a sequence of characters that define a search pattern. Usually such patterns are used by string-searching algorithms for 'find' or 'find and replace' operations on strings, or for input validation.*/

tools/drush.sh

@@ -0,0 +1,66 @@
+##############################################################################
+# DRUSH
+# Install: https://www.drush.org/install/
+# Usage: https://www.drush.org/usage/
+##############################################################################
+
+
+cache clear (cc)        # Clear all caches.
+
+cron                    # Run all cron hooks.
+
+disable (dis)           # Disable one or more modules.
+
+download (dl)           # Download core Drupal and projects like CCK, Zen, etc.
+
+enable (en)             # Enable one or more modules.
+
+eval                    # Evaluate arbitrary php code after bootstrapping Drupal.
+
+help                    # Print this help message. Use --filter to limit command list to one command file (e.g. --filter=pm)
+
+info                    # Release information for a project
+
+installcore (ic)        # Install Drupal core via the specified install profile. Note that updating core with Drush is not yet available. See http://drupal.org/node/434944.
+
+refresh (rf)            # Refresh update status information script Runs the given php script(s) after a full Drupal bootstrap. NOTE: you can't supply absolute paths to the script e.g. ~/Desktop/script.php won't work Desktop/script.php will
+
+sql cli (sqlc)          # Open a SQL command-line interface using Drupal?s credentials.
+
+sql conf                # Print database connection details.
+
+sql connect             # A string for connecting to the DB.
+
+sql dump                # Exports the Drupal DB as SQL using mysqldump.
+
+sql load                # Copy source database to target database.
+
+sql query (sqlq)        # Execute a query against the site database.
+
+status (st)             # Provides a birds-eye view of the current Drupal installation, if any.
+
+statusmodules (sm)      # Show module enabled/disabled status
+
+sync                    # Rsync the Drupal tree to/from another server using ssh.
+
+test clean              # Delete leftover tables and files from prior test runs.
+
+test mail               # Run all tests and mail the results to your team.
+
+uninstall               # Uninstall one or more modules.
+
+update (up)             # Update your project code and apply any database updates required (update.php)
+
+updatecode (upc)        # Update your project code. Moves existing project files to the backup directory specified in the config.
+
+updatedb (updb)         # Execute the update.php process from the command line.
+
+variable delete (vdel)  # Delete a variable.
+
+variable get (vget)     # Get a list of some or all site variables and values.
+
+variable set (vset)     # Set a variable.
+
+watchdog delete (wd)    # Delete all messages or only those of a specified type.
+
+watchdog show (ws)      # Shows recent watchdog log messages. Optionally filter for a specific type.

tools/git.sh

@@ -1,28 +1,55 @@
 git init            # initiates git in the current directory
 git clone <address> # creates a git repo from given address (get the address from your git-server)
+git clone <address> -b <branch_name> <path/to/directory>  # clones a git repo from the address into the given directory and checkout's the given branch
+git clone <address> -b <branch_name> --single-branch  # Clones a single branch
 
 git add file.txt   # adds(stages) file.txt to the git
 git add *          # adds(stages) all new modifications, deletions, creations to the git
 git reset file.txt # Removes file.txt from the stage
+git reset --hard   # Throws away all your uncommitted changes, hard reset files to HEAD
 git rm file.txt    # removes file.txt both from git and file system
+git rm --cached file.txt # only removes file.txt both from git index
 git status         # shows the modifications and stuff that are not staged yet
 
 git branch                         # shows all the branches (current branch is shown with a star)
 git branch my-branch               # creates my-branch
 git branch -d my-branch            # deletes my-branch
-git checkout my-bracnch            # switches to my-branch
+git checkout my-branch         	   # switches to my-branch
 git merge my-branch                # merges my-branch to current branch
 git push origin --delete my-branch # delete remote branch
+git branch -m <new-branch-name>    # rename the branch
+git checkout --orphan <branch_name> # checkout a branch with no commit history
+git branch -vv                     # list all branches and their upstreams, as well as last commit on branch
+git branch -a                      # List all local and remote branches
 
-git cherry-pick <commit_id>        # merge the specified commit
+git cherry-pick <commit_id>                     # merge the specified commit
+git cherry-pick <commit_id_A>^..<commit_id_B>   # pick the entire range of commits where A is older than B ( the ^ is for including A as well )
 
 git remote                         # shows the remotes
 git remote -v                      # shows the remote for pull and push
 git remote add my-remote <address> # creates a remote (get the address from your git-server)
+git remote rm my-remote            # Remove a remote
 
 git log                      # shows the log of commits
+git log --oneline            # shows the log of commits, each commit in a single line
+git log -p <file_name>       # change over time for a specific file
+git log <Branch1> ^<Branch2> # lists commit(s) in branch1 that are not in branch2
+git log -n <x>               # lists the last x commits
+git log -n <x> --oneline     # lists the last x commits, each commit in single line
+git grep --heading --line-number '<string/regex>' # Find lines matching the pattern in tracked files
+git log --grep='<string/regex>'                   # Search Commit log
+
 git commit -m "msg"          # commit changes with a msg
+git commit --amend           # combine staged changes with the previous commit, or edit the previous commit message without changing its snapshot
+git commit --amend --no-edit # amends a commit without changing its commit message
+git commit --amend --author='Author Name <email@address.com>'    # Amend the author of a commit
 git push my-remote my-branch # pushes the commits to the my-remote in my-branch (does not push the tags)
+git revert <commit-id>       # Undo a commit by creating a new commit
+
+git show                     # shows one or more objects (blobs, trees, tags and commits).
+git diff                     # show changes between commits, commit and working tree
+git diff --color             # show colored diff
+git diff --staged            # Shows changes staged for commit
 
 git tag                           # shows all the tags
 git tag -a v1.0 -m "msg"          # creates an annotated tag
@@ -39,7 +66,7 @@ git stash -u                         # stash everything including new untracked
 git stash save "msg"                 # stash with a msg
 git stash list                       # list all stashes
 git stash pop                        # delete the recent stash and applies it
-git stash stach@{2}                  # delete the {2} stash and applies it
+git stash pop stash@{2}              # delete the {2} stash and applies it
 git stash show                       # shows the description of stash
 git stash apply                      # keep the stash and applies it to the git
 git stash branch my-branch stash@{1} # creates a branch from your stash
@@ -55,6 +82,11 @@ git clean -f -d/git clean -fd     # To remove directories permanently
 git clean -f -X/git clean -fX     # To remove ignored files permanently
 git clean -f -x/git clean -fx     # To remove ignored and non-ignored files permanently
 
+git config --global --list                   # lists the git configuration for all repos
+git config --global --edit                   # opens an editor to edit the git config file
+git config --global alias.<handle> <command> # add git aliases to speed up workflow , eg. if  handle is st and command is status then running git st would execute git status 
+
+
 .gitignore
 # is a file including names of stuff that you don"t want to be staged or tracked.
 # You usually keep your local files like database, media, and etc here.
@@ -64,4 +96,3 @@ git clean -f -x/git clean -fx     # To remove ignored and non-ignored files perm
 # is a hidden directory in repo directory including git files. It is created after "git init".
 
 
-

tools/heroku.sh

@@ -100,6 +100,8 @@ git config --global --remove-section url.ssh://git@heroku.com/       # To remove
 ### Managing and deploying applications on Heroku (Using Docker)     ###################################
 #####################################################################################################
 
+# Setting stack of your app to a Container
+heroku stack:set container
 
 heroku container:login            # Login to the container resistry
 git clone https://github.com/heroku/alpinehelloworld.git       # Get sample code by cloning into the following repository

tools/nginx.sh

@@ -4,6 +4,212 @@
 ##############################################################################
 
 sudo nginx -t # Check syntax
+sudo systemctl status nginx # nginx current status
 sudo systemctl reload nginx # Reload nginx
-sudo service nginx restart  # Restart nginx
+sudo systemctl restart nginx  # Restart nginx
 sudo ln -s /etc/nginx/sites-available/example.com /etc/nginx/sites-enabled/ # Link website
+
+# *****************************************************************************
+# General Settings
+# *****************************************************************************
+
+# Ports
+
+server {
+  # Use HTTP protocol
+  listen 80;
+  
+  # Use HTTPS protocol
+  listen 443 ssl;
+  
+  # Listen on port 80 using IPv6
+  listen [::]:80;
+  
+  # Listen on port 80 using **only** IPv6
+  listen [::]:80 ipv6only=on;
+}
+
+# Domain name (server_name)
+
+server {
+  # Listen to example.com
+  server_name example.com;
+  
+  # Listen to multiple domains
+  server_name example.com www.example.com;
+  
+  # Listen to all sub-domains
+  server_name *.example.com;
+  
+  # Listen to all top-level domains
+  server_name example.*;
+  
+  # Listen to unspecified hostnames (listens to IP address itself)
+  server_name "";
+}
+
+# *****************************************************************************
+# Serving Files 
+# *****************************************************************************
+
+# Static assets (traditional web server)
+
+server {
+    listen 80;
+    server_name example.com;
+
+    root /path/to/website;
+    # root /www/data/ for example
+
+    # If there's no 'root' inside, it will look for /www/data/index.html
+    location / {
+    }
+
+    # If there's no 'root' inside, it will look for /www/data/images/index.html
+    location /images/ {
+    }
+
+    # Since there's 'root' inside, it will look for /www/media/videos/index.html
+    location /videos/ {
+        root /www/media;
+    }
+}
+
+# *****************************************************************************
+# Redirects
+# *****************************************************************************
+
+# 301 Permanent
+
+server {
+    # Redirect www.example.com to example.com
+    listen 80;
+    server_name www.example.com;
+    return 301 http://example.com$request_uri;
+}
+
+server {
+    # Redirect http to https
+    listen 80;
+    server_name example.com;
+    return 301 https://example.com$request_uri;
+}
+
+# 302 Temporary
+
+server {
+  listen 80;
+  server_name yourdomain.com;
+  return 302 http://otherdomain.com;
+}
+
+# *****************************************************************************
+# Reverse proxy
+# *****************************************************************************
+
+# Useful for Node.js, Streamlit, Jupyter, etc
+
+# Basic
+
+server {
+  listen 80;
+  server_name example.com;
+  
+  location / {
+    proxy_pass http://0.0.0.0:3000;
+    # where 0.0.0.0:3000 is your Node.js Server bound on 0.0.0.0 listing on port 3000
+  }
+}
+
+# Basic + (upstream)
+
+upstream node_js {
+  server 0.0.0.0:3000;
+  # where 0.0.0.0:3000 is your Node.js Server bound on 0.0.0.0 listing on port 3000
+}
+
+server {
+  listen 80;
+  server_name example.com;
+  
+  location / {
+    proxy_pass http://node_js;
+  }
+}
+
+# Upgraded Connection (useful for applications with support for WebSockets)
+
+upstream node_js {
+  server 0.0.0.0:3000;
+}
+
+server {
+  listen 80;
+  server_name example.com;
+  
+  location / {
+    proxy_pass http://node_js;
+    proxy_redirect off;
+    proxy_http_version 1.1;
+    proxy_set_header Upgrade $http_upgrade;
+    proxy_set_header Connection "upgrade";
+    proxy_set_header Host $host;
+	
+    }
+}
+
+# *****************************************************************************
+# HTTPS Protocol
+# *****************************************************************************
+
+# The majority of SSL options depend on what your application does or needs
+
+server {
+    listen 443 ssl;
+    server_name example.com;
+
+    ssl on;
+
+    ssl_certificate /path/to/cert.pem;
+    ssl_certificate_key /path/to/privkey.pem;
+
+    ssl_stapling on;
+    ssl_stapling_verify on;
+    ssl_trusted_certificate /path/to/fullchain.pem;
+
+    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
+    ssl_session_timeout 1d;
+    ssl_session_cache shared:SSL:50m;
+    add_header Strict-Transport-Security max-age=15768000;
+}
+
+# Permanent redirect to HTTPS secured domain
+
+server {
+  listen 80;
+  server_name yourdomain.com;
+  return 301 https://$host$request_uri;
+}
+
+# You can easily secure you website/app using Let's Encrypt.
+# Go https://certbot.eff.org/lets-encrypt/ubuntuxenial-nginx.html for more information
+
+# *****************************************************************************
+# Load Balancing
+# *****************************************************************************
+
+# Useful for large applications running in multiple instances. Below example is for reverse proxy
+upstream node_js {
+  server 0.0.0.0:3000;
+  server 0.0.0.0:4000;
+  server 127.155.142.421;
+}
+
+server {
+  listen 80;
+  server_name example.com;
+  
+  location / {
+    proxy_pass http://node_js;
+  }
+}

tools/vim.txt

@@ -87,6 +87,7 @@ J                   join line below to the current one
 cc                  change (replace) an entire line
 cw                  change (replace) to the end of word
 C                   change (replace) to the end of line
+ct'                 change (replace) until the ' character (can change ' for any character)
 s                   delete character at cursor and substitute text
 S                   delete line at cursor and substitute text (same as cc)
 xp                  transpose two letters (delete and paste, technically)
@@ -118,6 +119,7 @@ x                   delete current character
 X                   delete previous character
 dw                  delete the current word
 dd                  delete (cut) a line
+dt'                 delete until the next ' character on the line (replace ' by any character)
 D                   delete from cursor to end of line
 :[range]d           delete [range] lines
 
@@ -279,6 +281,7 @@ CTRL-w <            increase window width
 CTRL-w >            decrease window width
 CTRL-w =            equal window
 CTRL-w o            close other windows
+zz                  Centers the window to the current line
 
 
 ##############################################################################

tools/vscode.md

@@ -4,89 +4,89 @@
 
 ### HTML & CSS
 
-- `CSScomb`: Coding style formatter for CSS, Less, SCSS and Saas.
+- [`CSScomb`](https://marketplace.visualstudio.com/items?itemName=mrmlnc.vscode-csscomb): Coding style formatter for CSS, Less, SCSS and Saas.
 
-- `Puglint`: Linter and style checker for pug.
+- [`Puglint`](https://marketplace.visualstudio.com/items?itemName=mrmlnc.vscode-puglint): Linter and style checker for pug.
 
-- `Sass`: Indented Sass syntax highlighting, autocomplete & snippets.
+- [`Sass`](https://marketplace.visualstudio.com/items?itemName=Syler.sass-indented): Indented Sass syntax highlighting, autocomplete & snippets.
 
-- `SCSS IntelliSense`: Advanced autocompletion and refactoring support for SCSS.
+- [`SCSS IntelliSense`](https://marketplace.visualstudio.com/items?itemName=mrmlnc.vscode-scss): Advanced autocompletion and refactoring support for SCSS.
 
-- `XML Format`: Format XML documents.
+- [`XML Format`](https://marketplace.visualstudio.com/items?itemName=mikeburgh.xml-format): Format XML documents.
 
 ### JavaScript, Node & NPM
 
-- `Import Cost`: This extension will display inline in the editor the size of the imported package.
+- [`Import Cost`](https://marketplace.visualstudio.com/items?itemName=wix.vscode-import-cost): This extension will display inline in the editor the size of the imported package.
 
-- `ESLint`: Integrates ESLint into VS Code
+- [`ESLint`](https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint): Integrates ESLint into VS Code
 
-- `NPM`: NPM support for VS Code.
+- [`NPM`](https://marketplace.visualstudio.com/items?itemName=eg2.vscode-npm-script): NPM support for VS Code.
 
-- `NPM Intellisense`: Visual Studio Code plugin that autocompletes NPM modules in import statements.
+- [`NPM Intellisense`](https://marketplace.visualstudio.com/items?itemName=christian-kohler.npm-intellisense): Visual Studio Code plugin that autocompletes NPM modules in import statements.
 
-- `Version Lens`: Shows the latest version for each package using code lens.
+- [`Version Lens`](https://marketplace.visualstudio.com/items?itemName=pflannery.vscode-versionlens): Shows the latest version for each package using code lens.
 
-- `Vetur`: Vue tooling for VS Code.
+- [`Vetur`](https://marketplace.visualstudio.com/items?itemName=octref.vetur): Vue tooling for VS Code.
 
 ### PHP
 
-- `Better PHPUnit`: A better PHPUnit test runner.
+- [`Better PHPUnit`](https://marketplace.visualstudio.com/items?itemName=calebporzio.better-phpunit): A better PHPUnit test runner.
 
-- `Laravel Artisan`: Laravel Artisan commands within Visual Studio Code.
+- [`Laravel Artisan`](https://marketplace.visualstudio.com/items?itemName=ryannaddy.laravel-artisan): Laravel Artisan commands within Visual Studio Code.
 
-- `PHP CS Fixer`: PHP CS Fixer extension for VS Code, php formatter, php code beautify tool.
+- [`PHP CS Fixer`](https://marketplace.visualstudio.com/items?itemName=junstyle.php-cs-fixer): PHP CS Fixer extension for VS Code, php formatter, php code beautify tool.
 
-- `PHP Doc Comment VSCode Plugin`: Add phpdoc @param and @return tag for selected function signatures.
+- [`PHP Doc Comment VSCode Plugin`](https://marketplace.visualstudio.com/items?itemName=rexshi.phpdoc-comment-vscode-plugin): Add phpdoc @param and @return tag for selected function signatures.
 
-- `PHP IntelliSense`: Advanced Autocompletion and Refactoring support for PHP.
+- [`PHP IntelliSense`](https://marketplace.visualstudio.com/items?itemName=felixfbecker.php-intellisense): Advanced Autocompletion and Refactoring support for PHP.
 
 ### Git
 
-- `Git History`: View git log, file history, compare branches or commits.
+- [`Git History`](https://marketplace.visualstudio.com/items?itemName=donjayamanne.githistory): View git log, file history, compare branches or commits.
 
-- `Gitignore`: A extension for Visual Studio Code that assists you in working with .gitignore files.
+- [`Gitignore`](https://marketplace.visualstudio.com/items?itemName=codezombiech.gitignore): A extension for Visual Studio Code that assists you in working with .gitignore files.
 
 ### Themes
 
-- `Material Icon Theme`: Material Design Icons for Visual Studio Code.
+- [`Material Icon Theme`](https://marketplace.visualstudio.com/items?itemName=PKief.material-icon-theme): Material Design Icons for Visual Studio Code.
 
-- `Palenight Theme`: An elegant and juicy material-like theme for Visual Studio Code.
+- [`Palenight Theme`](https://marketplace.visualstudio.com/items?itemName=whizkydee.material-palenight-theme): An elegant and juicy material-like theme for Visual Studio Code.
 
 ### Handy
 
-- `Better comments`: Improve your code commenting by annotating with alert, informational, TODOs, and more!
+- [`Better comments`](https://marketplace.visualstudio.com/items?itemName=aaron-bond.better-comments): Improve your code commenting by annotating with alert, informational, TODOs, and more!
 
-- `Debugger for Chrome`: Debug your JavaScript code in the Chrome browser.
+- [`Debugger for Chrome`](https://marketplace.visualstudio.com/items?itemName=msjsdiag.debugger-for-chrome): Debug your JavaScript code in the Chrome browser.
 
-- `EditorConfig for VS Code`: EditorConfig Support for Visual Studio Code.
+- [`EditorConfig for VS Code`](https://marketplace.visualstudio.com/items?itemName=EditorConfig.EditorConfig): EditorConfig Support for Visual Studio Code.
 
-- `File Utils`: A convenient way of creating, duplicating, moving, renaming and deleting files and directories.
+- [`File Utils`](https://marketplace.visualstudio.com/items?itemName=sleistner.vscode-fileutils): A convenient way of creating, duplicating, moving, renaming and deleting files and directories.
 
-- `Final-Newline`: Inserts a final newline when saving the document.
+- [`Final-Newline`](https://marketplace.visualstudio.com/items?itemName=samverschueren.final-newline): Inserts a final newline when saving the document.
 
-- `Formatting Toggle`: A VS Code extension that allows you to toggle the formatter (Prettier, Beautify, …) ON and OFF with a simple click.
+- [`Formatting Toggle`](https://marketplace.visualstudio.com/items?itemName=tombonnike.vscode-status-bar-format-toggle): A VS Code extension that allows you to toggle the formatter (Prettier, Beautify, …) ON and OFF with a simple click.
 
-- `Open in Github/Bitbucket...`: Jump to a source code line in Github / Bitbucket, Gitlab, VisualStudio.com
+- [`Open in Github/Bitbucket...`](https://marketplace.visualstudio.com/items?itemName=ziyasal.vscode-open-in-github): Jump to a source code line in Github / Bitbucket, Gitlab, VisualStudio.com
 
-- `OpenChrome`: Open file with Chrome.
+- [`OpenChrome`](https://marketplace.visualstudio.com/items?itemName=huazaierli.openchrome&ssr=false#overview): Open file with Chrome.
 
-- `Output Colorizer`: Syntax Highlighting for log files.
+- [`Output Colorizer`](https://marketplace.visualstudio.com/items?itemName=IBM.output-colorizer): Syntax Highlighting for log files.
 
-- `Prettier - Code formatter`: VS Code plugin for prettier/prettier.
+- [`Prettier - Code formatter`](https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode): VS Code plugin for prettier/prettier.
 
-- `Project Manager`: Easily switch between projects.
+- [`Project Manager`](https://marketplace.visualstudio.com/items?itemName=alefragnani.project-manager): Easily switch between projects.
 
-- `REST Client`: REST Client for Visual Studio Code.
+- [`REST Client`](https://marketplace.visualstudio.com/items?itemName=humao.rest-client): REST Client for Visual Studio Code.
 
-- `SVG Viewer`: SVG Viewer for Visual Studio Code.
+- [`SVG Viewer`](https://marketplace.visualstudio.com/items?itemName=cssho.vscode-svgviewer): SVG Viewer for Visual Studio Code.
 
-- `Terminal`: Terminal for Visual Studio Code.
+- [`Terminal`](https://marketplace.visualstudio.com/items?itemName=formulahendry.terminal): Terminal for Visual Studio Code.
 
-- `Vue Peek`: Allows peek and goto definition for Vue single-file components.
+- [`Vue Peek`](https://marketplace.visualstudio.com/items?itemName=dariofuzinato.vue-peek): Allows peek and goto definition for Vue single-file components.
 
-- `VS Live Share`: Real-time collaborative development from the comfort of your favorite tools.
+- [`VS Live Share`](https://marketplace.visualstudio.com/items?itemName=MS-vsliveshare.vsliveshare): Real-time collaborative development from the comfort of your favorite tools.
 
-- `Wrap Console Log`: Wrap to console.log by word or selection.
+- [`Wrap Console Log`](https://marketplace.visualstudio.com/items?itemName=midnightsyntax.vscode-wrap-console-log): Wrap to console.log by word or selection.
 
 ## My Settings