Perl

1
Perl

• Robert Whiting
• COSC4153
• Spring 2008
• Assignment 11

2
Presentation Overview

• Brief History
• Basic Syntax and Semantics
• Example Source Code
• Uses in the world
• Advantages and Disadvantages
• Likes and Dislikes
• Bibliography

3
Brief History

• 1987 Perl 1.0 released by Larry Wall
• 1988 Perl 2.0 released
• 1989 Perl 3.0 released under GPL
• 1991 Perl 4.0 released
• 1993 MacPerl 4.0.2 released
• 1994 Perl 5.0 released
• 1997 Perl 6.0 released

4
Basic Syntax / Semantics

• print "Hello, world!\n"
• foo a scalar
• _at_foo an array
• foo a hash
• FOO a file handle or constant
• foo a subroutine. (The is optional)?

5
Example Source

• !/usr/bin/perl
• print join "\n", map "INSERT INTO tracks
  VALUES(" . (join ",", map (/\D/)? " '_' " _
  (eval my _at_E split "\t", _ my _at_S push _at_S,
  E_ foreach ( qw (10 0 1 3 7 25 21 12 5)) _at_S
  )) . ")" ltgt

6
Uses in the world

• Web applications (along with PHP and Python)?
• Glue applications
• Bioinformatics
• Single-line programs

7
Advantages / Disadvantages

• Powerful
• Compact
• Well supported
• Quickly growing

• Interpreted language
• Too powerful for mere mortals

8
Likes / Dislikes

• Short
• Compact
• Powerful
• Portable
• Widely accepted
• Well supported
• Proud community

• Hard to learn
• Hard to read
• Camels spit

9
Conclusion

• Three Virtues of a Programmer
• 1. Laziness - The quality that makes you write
  labor-saving programs
• 2. Impatience - The anger you feel when the
  computer is being lazy.
• 3. Hubris - Excessive pride, the quality that
  makes you write programs that other people won't
  want to say bad things about.
• Perl makes this possible.

10
Bibliography

• http//www.perl.org/
• http//www.wall.org/larry/
• http//en.wikipedia.org/wiki/Perl