Larry Wall created the Perl programming language in 1987. Perl is a general purpose language that is practical, flexible, and supports both procedural and object-oriented programming. It has a large community of users and third-party modules. Perl can be used for tasks like web development, system administration, and more. It has the philosophies of "there's more than one way to do it" and to "share and enjoy."

1. Perl
A STEP UP FROM BASH

2. Perl’s Creator: Larry Wall
• LarryWall, programmer, linguist, author, born March 10, 1949 in
Duncan, British Columbia, Canada. Perl computer language creation
in 1987.
• Quotes:
• The three chief virtues of a programmer are: Laziness, Impatience and Hubris
• There's MoreThan OneWay to Do It
• Add your first bullet point here
• Add your second bullet point here
• Add your third bullet point here

3. What is Perl
 Practical Extraction and Reporting Language
 Pathologically Eclectic Rubbish Lister
 “Perl” is the language
 “perl” is the compiler
 Never “PERL”
• Perl is a general-purpose programming language originally developed for text manipulation and
now used for a wide range of tasks including web development, system administration, network
programming, code generation and more.
• It's intended to be practical rather than beautiful.
• Supports both procedural and OO programming.
• It has one of the world's most impressive collections of third-party modules (http://www.cpan.org).

4. The Perl philosophy
• There’s more than one way to do it.
• Share and Enjoy!
• General Purpose Programming Language
• Open Source
• Fast
• Flexible
• Secure
• Fun
• Cross Plaform
• Large active user base
• Can look complicated, initially, particularly if you're not familiar with regular
expressions

5. Interpreting Perl
• In a File
• print “This is AWESOMMMMMEEEEEEEE!n”;
• On command line: perl script.pl
• #!/usr/bin/perl
• print “This is AWESOMMMMMEEEEEEEE!n”;
• On Command line ./script.pl
• On the shell
• perl –e ‘print “This is AWWEESSSOOMMEEEEEn” ’

6. Perl Syntax Overview
• White space is ignored
• Perl statements end with a semi-
colon.
print ("Hello, world!");
• Comments start with a # and run to
the end of the line.
# This is a comment
• Double quotes or single quotes may
be used around literal strings:
print("Hello, world!");
print ('Hello, world!');
• However, only double quotes
interpolate variables and special
characters such as newlines (n):
• Scalar variables start with a $
• Question: What is a scalar value?
• “ ”
• ‘ ’
• 42
• .0001
• 3.27e17
• Perl will automatically convert
between types as required.
• print('3' + 4.5); # prints
7.5
• Concatenation:Arithmetic operators
Vs.
.

7. Time Out to Code

8. Unique to Perl
PRAGMAS
• Perl is a permissive language
• A way to impose discipline is
with pragmas.
• A pragma is a directive to the
interpreter informing it about
some form of I/O with the code.
• use warnings; # display warnings
• use strict; #more restrictive to
assist in identification of mistakes
SPECIAL VARIABLES
• There are some ‘magic’ variables.
These special variables are used for all
kinds of purposes.
• $_: is the ‘default variable’.
• @ARGV: the command line arguments to
your script.
• $ARGV: contains the name of the current
file when reading from <> or
readline().
• @_: the arguments passed to a
subroutine.
• $a, $b: Special package variables when
using sort().
• $/:The input record separator, newline
by default.

9. Conditional Constructs
• The COND shall be conditional statement
surround by ( and ), and BLOCK shall be
one ore more statements surround by {
and }.
• if ( is_valid( $value ) )
{ … }
elsif (cond)
{ ...}
else
{ ...}
• Ex.
if ($zippy)
{
print("Yow!");
}

10. Arithmetic and String Operators
ARITHMETIC OPERATORS
 Standard arithmetic operations
 Less standard operations
modulus (%), exponentiation (**)
 $area = $pi * ($radius ** 2);
 Often need to do things like
$total = $total + $amount;
 Can be abbreviated to
$total += $amount;
 Even shorter
 $x++;
 $y--;
 Question:What is the subtle
difference between $x++ and ++$x?
STRING OPERATORS
 Concaternation (.)
 $name = $firstname . ' ' .
$surname;
 Repetition (x)
 $line = '-' x 80;
$police = 'hello ' x 3;
 Shortcut versions available
 $page .= $line; # $page
= $page . $line
 $thing x= $i; #
$thing = $thing x $i