turn the pushy_https behaviour on in cpan

 from terminal

type cpan

you get the cpan prompt

then

 o conf init pushy_https

yes

perl tk package install error " expected identifier or '(' before numeric constant" solved on windows 11

when trying

cpan install Tk

I was getting  lot of errors 

the solution is

just install strawberry perl

then from command line

cpanm https://github.com/Lamprecht/perl-tk.git@Strawberry-5.38-patch 

Source:https://stackoverflow.com/questions/78323022/installing-tk-on-strawberry-perl-leads-to-compiler-errors

Downloading and printing html css code of a page using perl and lwp

 use strict;
use warnings;
use LWP::Simple;
sub main{
print "Downloading ... \n";
print get("http://www.google.com/");
print "Finished\n";
}
main();

Perl loop assignment solved

 In this exercise, you will need to loop through and print out all even numbers from the @NUMBERS array in the same order they are received. Don't print any numbers that come after 237 in the array.

 

@NUMBERS = (951,402,984,651,360,69,408,319,601,485,980,507,725,547,544,615,83,165,141,501,263,617,865,575,219,390,237,412,566,826,248,866,950,626,949,687,217,815,67,104,58,512,24,892,894,767,553,81,379,843,831,445,742,717,958,609,842,451,688,753,854,685,93,857,440,380,126,721,328,753,470,743,527);


for($i=0;($i<=$#NUMBERS);$i+=1) {
if ($NUMBERS[$i]==237)
{
last;
}
if ($NUMBERS[$i]%2==0)
{
print $NUMBERS[$i]."\n";
}

} 

Perl way

@NUMBERS = (951,402,984,651,360,69,408,319,601,485,980,507,725,547,544,615,83,165,141,501,263,617,865,575,219,390,237,412,566,826,248,866,950,626,949,687,217,815,67,104,58,512,24,892,894,767,553,81,379,843,831,445,742,717,958,609,842,451,688,753,854,685,93,857,440,380,126,721,328,753,470,743,527);

foreach $number (@NUMBERS) {
    if ($number % 2 == 0) {
        print $number . "\n";
    }
    last if ($number == 237);
}

Perl Assignment solved using array and hash

 An array @family holds a list of family member names. The first hash %shoe_color contains favorite shoe color per person name. The second hash %shoe_size contains shoe size per person name.

Evaluate and print the favorite shoe color and shoe size per each family member. For shoe sizes 10 and above, add the word 'large' to the output line.

Output lines should be in the format: "Homer wears large brown shoes size 12".

Note: not all family members may be included in the hash variables, so you better conditionally check if they exist or not (using the exists operator). If a name does not exist, add the key/value pair into the hash variables - for show color add: black; for shoe size add 99.

Solution

@family = ('Homer', 'Moe', 'Maggie');
%shoe_color = ('Lisa' => 'red', 'Homer' => 'brown', 'Maggie' => 'pink', 'Marge' => 'blue', 'Bart' => 'yellow');
%shoe_size = ('Moe' => 9, 'Lisa' => 7, 'Homer' => 12, 'Bart' => 8, 'Maggie' => 4);

$default_shoe_color = "black";
$default_shoe_size = 4;

$member = $family[0];
if (!exists $shoe_color{$member}) {
    $shoe_color{$member} = $default_shoe_color;
}
if (!exists $shoe_size{$member}) {
    $shoe_size{$member} = $default_shoe_size;
}
$is_large = ($shoe_size{$member} >= 10) ? " large " : " ";
print "$member wears$is_large$shoe_color{$member} shoes size $shoe_size{$member}\n";

$member = $family[1];
if (!exists $shoe_color{$member}) {
    $shoe_color{$member} = $default_shoe_color;
}
if (!exists $shoe_size{$member}) {
    $shoe_size{$member} = $default_shoe_size;
}
$is_large = ($shoe_size{$member} >= 10) ? " large " : " ";
print "$member wears$is_large$shoe_color{$member} shoes size $shoe_size{$member}\n";

$member = $family[2];
if (!exists $shoe_color{$member}) {
    $shoe_color{$member} = $default_shoe_color;
}
if (!exists $shoe_size{$member}) {
    $shoe_size{$member} = $default_shoe_size;
}
$is_large = ($shoe_size{$member} >= 10) ? " large " : " ";
print "$member wears$is_large$shoe_color{$member} shoes size $shoe_size{$member}\n";

Perl assignment solved using array and hash

 Assign the hash variable called car_catalog to include the following car models and their showroom prices in dollars. Use the car model name as the hash key. The cars and prices are:

    Model: BMW Series 5, price: 100000
    Model: Mercedes 2000, price: 250000
    Model: Toyota Corolla, price: 20000
    Model: Lexus 3, price: 95000

Assign an array variable called my_wishlist with the two cars you want to buy: the first array element is the full model name of the BMW car and the second array model is the full model name of the Toyota car. Use the array variable contents as keys to the hash variable in order to print lines in the following format: "I would like to buy one for the price of Dollars."

Solution

%car_catalog = ("BMW Series 5" => 100000 , "Mercedes 2000" => 250000, "Toyota Corolla" => 20000,"Lexus 3"=>95000);
@my_wishlist = ("BMW Series 5","Toyota Corolla");
print "I would like to buy one $my_wishlist[0] for the price of $car_catalog{$my_wishlist[0]} Dollars.\n";
print "I would like to buy one $my_wishlist[1] for the price of $car_catalog{$my_wishlist[1]} Dollars.\n";

 

 

Source:https://www.learn-perl.org/en/Variables_and_Types

Array and hash example in perl

 @item_price_list = (5 , 8 , 24);
@item_name_list = ("Apple", "Banana", "Mushroom");
print "The price of one $item_name_list[0] is $item_price_list[0] gold coins.\n";
print "The price of one $item_name_list[1] is $item_price_list[1] gold coins.\n";
print "The price of one $item_name_list[2] is $item_price_list[2] gold coins.\n";


%item_catalog = ("Apple" => 5 , "Banana" => 8, "Mushroom" => 24);
# note the required backslash to escape the double-quotes around the key string Apple
print "The price of one Apple is $item_catalog{\"Apple\"} gold coins.\n";
$item_name = "Banana";
print "The price of one $item_name is $item_catalog{$item_name} gold coins.\n";
@item_name_list = ("Apple", "Banana", "Mushroom");
print "The price of one $item_name_list[2] is $item_catalog{$item_name_list[2]} gold coins.\n";

Calculate the area of a right angle triangle using a package in perl

 

package Triangle;   # class name

sub new {

  my $class = shift;

  my $self = {

      _length => shift,

      _height => shift,

  };

 

  # Print all the values just for clarification.

  print "Length is $self->{_length}\n";

  print "Height is $self->{_height}\n";

  bless $self, $class;

  return $self;

}

sub area{

    my ($self) = @_;

    return ($self->{_length} * $self->{_height}) / 2;

  }

1;

$object = new Triangle( 4, 5);

print "Area of Triangle: " . $object->area();

Sorting array of numbers in perl

 

@numbers = (13, 9, 22, 27, 1, 3, -4, 10);

print "Original: @numbers\n\n";

@sorted_numbers = sort { $a <=> $b } @numbers;

print "After sorting: @sorted_numbers";

Sorting array of strings in perl

 

#defining and array

@fruits = ('Rasberry', 'Orange', 'Apricot','Banana', 'Apple','Olive' );

@fruits = sort(@fruits); #applying the sort function

print("@fruits"); #printing the sorted array

matrix assignment in perl

 sub printMat {
  #write the code for making and printing the matrix here
  #use can use \n to move numers to next line in the matrix
  #use " " to add space between numbers in matrix
  #print "Write your code below"; #comment out this line when you start writing cod
  for ($i = 0; $i < 4 ; $i++) {
    for ($j = 0; $j < 4; $j++) {
      if ($i==$j)
      {
        $val=0;
      }
      elsif($j<$i)
      {
        $val=-1;
      }
      else{
        $val=1;
      }
       $comparisonAdjectives[$i][$j] = $val;

    }
  }

  for ($i = 0; $i < 4 ; $i++) {
    for ($j = 0; $j < 4; $j++) {
      if ($comparisonAdjectives[$i][$j]>=0){
          print " ".$comparisonAdjectives[$i][$j]." ";
      }
      else
      {
          print $comparisonAdjectives[$i][$j]." ";
      }
      
    }
    print "\n";
  }
}

printMat();

Multidimensional array in perl

 

@comparisonAdjectives= (["good", "better", "best"],

                        ["bad", "worse", "worst"],

                        ["tall", "taller", "tallest"]);

for ($i = 0; $i < 3 ; $i++) {

    for ($j = 0; $j < 3; $j++) {

        print $comparisonAdjectives[$i][$j] . " ";

    }

    print "\n";

}

Find maximum value from an array using perl

 

 #Returns maximum value from Array passed as parameter

  sub Find_Maximum {

  my @list = @_;

  $max = $list[0];

  for ($i = 1; $i <= $#list; $i++) { #iterate over all the array elements

    if ($list[$i] > $max) {                 #check if current element is greater than the already

      #stored max value

      $max = $list[$i];                     # if yes then update the max value to current element

    }

  }

  return $max;                           #return the maximum value

}#end of Find_Maximum()

@array = (15, 6, 3, 21, 19, 4);

print Find_Maximum (@array);

Find length of an array in perl

 

@fruits = ("Orange", "Grapefruit", "Lemon");#initializing associative array

print "Length of fruits array is " . scalar(@fruits);

Shift and Unshift in perl

 

@alphabets = (a .. f);

print "Original: @alphabets \n";

shift (@alphabets);   # removing first element of the array

print "Removing first element from an array: @alphabets\n";

unshift (@alphabets, 'a');   # adding last element of the array

print "Adding first element to an array: @alphabets";

push and pop in perl

 @alphabets = (A .. F);

print "Original: @alphabets \n";
push (@alphabets, 'G');   # add G to the last index array

print "Pushing G in the array: @alphabets\n";

pop (@alphabets);   # removing last element of array

print "Removing last element from array: @alphabets\n";
pop (@alphabets);   # removing last element of array

print "Removing last element from array: @alphabets\n\n";

Declare and print an array in perl

 

@fruits = ('Grapes', 'Apple', 'Banana' );

print "@fruits";

Substring in perl

 

$foo = "Hello world";

@arr = split("",$foo);

print $arr[6]; # returns w

print "\n";

print substr($foo, 6, 5); # returns 'world'

 

Finding position of a substring

In Perl, we can use the index method to get the first position/occurrence of a substring

 

 in another string. If the substring does not exist, the index returns -1.

 

 

$str = "The occurence of hay is hay at position:";

print $str . index($str, "hay")."\n";

 

Concatenation of two strings in perl

 

$a = "water";

$b = " bottle";

$c = $a . $b; # $c => water bottle

print $c;

 

 

 

$a = "Hello";

$a .= " World"; # $a => Hello World

print $a;

 

Programming assignment in perl

 

sub gpa_Point{

  $grade = @_[0];

 

    if($grade eq "A+")

    {return 4;}

    elsif($grade eq "A")

    { return 4;}

    elsif($grade eq "A-")

    {return 3.7;}

    elsif($grade eq "B+")

    { return 3.3;}

    elsif($grade eq "B")

    { return 3;}

    elsif($grade eq "B-")

    { return 2.8;}

    elsif($grade eq "C+")

    { return 2.5;}

    elsif($grade eq "C")

    { return 2;}

    elsif($grade eq "C-")

    { return 1.8;}

    elsif($grade eq "D")

    { return 1.5;}

    elsif($grade eq "F")

    { return 0;}

    else

    {return -1;}

  }

  print gpa_Point("b-"); # change value to check for multiple grades