Perl Tutorial

• Introduction to Perl
• Installation and Environment Setup
• Syntax of a Perl Program
• Hello World Program in Perl
• Perl vs C/C++
• Perl vs Java
• Perl vs Python

Fundamentals

• Modes of Writing a Perl Code
• Boolean Values
• Operators
• Variables
• Variables and its Types
• Scope of Variables
• Modules in Perl
• Packages in Perl
• Number and its Types
• Directories with CRUD operations

Input and Output

• Use of print() and say() in Perl
• Perl | print operator
• Use of STDIN for Input

Control Flow

• Decision Making
• Loops
• Perl given-when Statement
• Perl goto operator
• next operator
• redo operator
• last in loop

Arrays and Lists

• Arrays
• Array Slices
• Getting the Number of Elements of an Array
• Reverse an array
• Sorting of Arrays
• Useful Array functions
• Arrays (push, pop, shift, unshift)
• Implementing a Stack
• List and its Types
• List Functions

Hash

• Introduction to Hash
• Working of a Hash
• Hash Operations
• Sorting a Hash
• Multidimensional Hashes
• Hash in Scalar and List Context
• Useful Hash functions

Scalars

• Scalars
• Comparing Scalars
• scalar keyword

Strings

• Quoted, Interpolated and Escaped Strings
• Multi-line Strings | Here Document
• Sorting mixed Strings in Perl
• String Operators
• Useful String Operators
• String functions (length, lc, uc, index, rindex)
• Useful String functions
• Automatic String to Number Conversion or Casting
• Count the frequency of words in text
• Removing leading and trailing white spaces (trim)

Object Oriented Programming in Perl

• Introduction to OOPs
• Classes
• Objects
• Methods
• Constructors and Destructors
• Method Overriding
• Inheritance
• Polymorphism
• Encapsulation

Subroutines

• Subroutines or Functions
• Function Signature in Perl
• Passing Complex Parameters to a Subroutine
• Mutable and Immutable parameters
• Multiple Subroutines
• Use of return() Function
• References
• Pass By Reference
• Recursion in Perl

Regular Expressions

• Regular Expressions
• Operators in Regular Expression
• Regex Character Classes
• Special Character Classes in Regular Expressions
• Quantifiers in Regular Expression
• Backtracking in Regular Expression
• ‘e’ modifier in Regex
• ‘ee’ Modifier in Regex
• pos() function in Regex
• Regex Cheat Sheet
• Searching in a File using regex

File Handling

• File Handling Introduction
• Opening and Reading a File
• Writing to a File
• Appending to a File
• Reading a CSV File
• File Test Operators
• File Locking
• Use of Slurp Module
• Useful File-handling functions

Context Sensitivity

• Scalar Context Sensitivity
• List Context Sensitivity
• STDIN in Scalar and List Context

CGI Programming

• CGI Programming
• File Upload in CGI
• GET vs POST in CGI

Misc

• Breakpoints of a Debugger
• Exiting from a Script
• Creating Excel Files
• Reading Excel Files
• Number Guessing Game using Perl
• Database management using DBI
• Accessing a Directory using File Globbing
• Use of Hash bang or Shebang line
• Useful Math functions

Math functions in Perl

Perl provides a rich set of mathematical functions for various operations. This tutorial will guide you through the basic math functions available in Perl.

1. Basic Arithmetic

Like most programming languages, Perl supports basic arithmetic operations:

• Addition: +
• Subtraction: -
• Multiplication: *
• Division: /
• Modulus (remainder): %
• Exponentiation: **

my $sum = 5 + 3;           # 8
my $difference = 5 - 3;   # 2
my $product = 5 * 3;      # 15
my $quotient = 8 / 2;     # 4
my $remainder = 8 % 5;    # 3
my $power = 2 ** 3;       # 8

2. The int Function

Rounds a floating-point number down to the nearest integer:

my $result = int(7.8);    # 7

3. The abs Function

Returns the absolute value of a number:

my $absolute = abs(-7);   # 7

4. The sqrt Function

Returns the square root of a number:

my $root = sqrt(16);      # 4

5. Trigonometric Functions

Perl provides functions like sin, cos, tan, asin, acos, and atan. They work with angles in radians.

my $sin_val = sin(3.14159265/2);  # ~1 (sin of 90 degrees)

To convert between degrees and radians:

use constant PI => 3.14159265;
my $radians = $degrees * (PI/180);
my $degrees = $radians * (180/PI);

6. Logarithm Functions

• log: Returns the natural logarithm (base e) of its argument.
• To compute logarithms with other bases: log($value) / log($base)

my $ln_val = log(2.71828);  # ~1
my $log_10 = log(100) / log(10);  # 2 (base 10 log of 100)

7. rand Function

Returns a random fractional number greater than or equal to 0 and less than the value of its argument. If no argument is provided, the default is 1.

my $random = rand(10);  # A number between 0 and 10 (not inclusive of 10)

8. srand Function

Seeds the random number generator. Calling srand without arguments seeds using the current time and process ID, which is usually sufficient for casual use.

srand(time);

9. Hexadecimal and Octal Conversions

• hex: Converts a string representing a hexadecimal number to its decimal value.
• oct: Converts a string representing an octal number to its decimal value.

my $decimal_from_hex = hex('A');  # 10
my $decimal_from_oct = oct('12'); # 10

10. Comparison Operators

• Numeric comparisons: ==, !=, <, <=, >, >=, <=>
• String comparisons: eq, ne, lt, le, gt, ge, cmp

The spaceship operator (<=>) returns -1, 0, or 1 if the left argument is less than, equal to, or greater than the right argument.

my $result = 5 <=> 10;  # -1

11. Summary

Perl offers a wide range of mathematical functions and operations suitable for a variety of tasks, from basic arithmetic to more complex calculations. By understanding these functions, you can implement math-centric algorithms and handle numerical data effectively in your Perl scripts.

1. Basic arithmetic operations in Perl:

   • Description: Performing basic arithmetic operations.
   • Code Example:

     my $a = 5;
     my $b = 3;
     
     my $sum = $a + $b;
     my $difference = $a - $b;
     my $product = $a * $b;
     my $quotient = $a / $b;
     

2. Using built-in mathematical functions in Perl:

   • Description: Utilizing built-in mathematical functions.
   • Code Example:

     my $num = 4.567;
     
     my $abs_value = abs($num);
     my $sqrt_value = sqrt($num);
     my $rounded_value = int($num);
     

3. Exponential and logarithmic functions in Perl:

   • Description: Using exponential and logarithmic functions.
   • Code Example:

     my $base = 2;
     my $exponential_result = $base ** 3;
     my $log_result = log($base);
     

4. Trigonometric functions in Perl:

   • Description: Employing trigonometric functions.
   • Code Example:

     use Math::Trig;
     
     my $angle_in_radians = 0.5;
     my $sin_result = sin($angle_in_radians);
     my $cos_result = cos($angle_in_radians);
     

5. Random number generation in Perl:

   • Description: Generating random numbers.
   • Code Example:

     my $random_number = int(rand(10));  # Random integer between 0 and 9
     

6. Numeric rounding and formatting in Perl:

   • Description: Rounding and formatting numeric values.
   • Code Example:

     my $value = 3.14159;
     
     my $rounded_value = sprintf("%.2f", $value);  # Rounds to 2 decimal places
     

7. Complex number operations in Perl:

   • Description: Simulating complex number operations.
   • Code Example:

     use Math::Complex;
     
     my $complex_num1 = Math::Complex->make(2, 3);
     my $complex_num2 = Math::Complex->make(1, -2);
     
     my $sum_complex = $complex_num1 + $complex_num2;
     

8. Bitwise operations in Perl:

   • Description: Performing bitwise operations.
   • Code Example:

     my $num1 = 5;
     my $num2 = 3;
     
     my $bitwise_and = $num1 & $num2;
     my $bitwise_or = $num1 | $num2;
     my $bitwise_xor = $num1 ^ $num2;
     

9. Custom math functions in Perl:

   • Description: Creating custom mathematical functions.
   • Code Example:

     sub square {
         my ($num) = @_;
         return $num ** 2;
     }
     
     my $result = square(4);