Perl Maven

Preface

1. Error reporting
2. Changes
3. v0.06 2018-05-05
4. v0.05 2018-04-04
5. v0.04 2018-03-24

Overview

1. Perl tutorial

Introduction

1. Installing and getting started with Perl
2. The Hash-bang line, or how to make a Perl scripts executable on Linux
3. Perl Editor
4. How to get Help for Perl?
5. Perl on the command line
6. Core Perl documentation and CPAN module documentation
7. POD - Plain Old Documentation
8. Debugging Perl scripts

Scalars

1. Common Warnings and Error messages in Perl
2. Prompt, read from STDIN, read from the keyboard in Perl
3. Automatic string to number conversion or casting in Perl
4. Conditional statements, using if, else, elsif in Perl
5. Boolean values in Perl
6. Numerical operators
7. String operators: concatenation (.), repetition (x)
8. undef, the initial value and the defined function of Perl
9. Strings in Perl: quoted, interpolated and escaped
10. Here documents, or how to create multi-line strings in Perl
11. Scalar variables
12. Comparing scalars in Perl
13. String functions: length, lc, uc, index, substr
14. Number Guessing game
15. while loop
16. Scope of variables in Perl
17. Short-circuit in boolean expressions

Files

1. How to exit from a Perl script?
2. Standard output, standard error and command line redirection
3. Warning when something goes wrong
4. What does die do?
5. Writing to files with Perl
6. Appending to files
7. Open and read from text files
8. Don’t Open Files in the old way
9. Reading and writing binary files in Perl
10. EOF - End of file in Perl
11. tell how far have we read a file
12. slurp mode - reading a file in one step

Lists and Arrays

1. Perl for loop explained with examples
2. Perl Arrays
3. Processing command line arguments - @ARGV in Perl
4. How to process command line arguments in Perl using Getopt::Long
5. Advanced usage of Getopt::Long for accepting command line arguments
6. Perl split - to cut up a string into pieces
7. How to read a CSV file using Perl?
8. join
9. The year of 19100
10. Scalar and List context in Perl, the size of an array
11. Reading from a file in scalar and list context
12. STDIN in scalar and list context
13. Sorting arrays in Perl
14. Sorting mixed strings
15. Unique values in an array in Perl
16. Manipulating Perl arrays: shift, unshift, push, pop
17. Reverse Polish Calculator in Perl using a stack
18. Using a queue in Perl
19. Reverse an array, a string or a number
20. The ternary operator in Perl
21. min, max, sum in Perl using List::Util
22. qw - quote word

Subroutines

1. Subroutines and functions in Perl
2. Passing multiple parameters to a function in Perl
3. Variable number of parameters in Perl subroutines
4. Understanding recursive subroutines - traversing a directory tree

Hashes

1. Hashes in Perl
2. Creating a hash from an array in Perl
3. Perl hash in scalar and list context
4. exists - check if a key exists in a hash
5. How to sort a hash in Perl?
6. Count the frequency of words in text using Perl

Regular Expressions

1. Introduction to Regexes in Perl 5
2. Regex character classes
3. Regex: special character classes
4. Perl 5 Regex Quantifiers
5. trim - removing leading and trailing white spaces with Perl
6. Perl 5 Regex Cheat sheet

Shell related functionality

1. What are -e, -z, -s, -M, -A, -C, -r, -w, -x, -o, -f, -d , -l in Perl?
2. Current working directory in Perl (cwd, pwd)
3. Running external programs from Perl with system
4. How to remove, copy or rename a file with Perl
5. Reading the content of a directory
6. Traversing the filesystem - using a queue

CPAN

1. Download and install Perl
2. Installing a Perl Module from CPAN on Windows, Linux and Mac OSX
3. How to change @INC to find Perl modules in non-standard locations
4. How to add a relative directory to @INC

Examples for using Perl

1. How to replace a string in a file with Perl
2. How to read an Excel file in Perl
3. How to create an Excel file with Perl?
4. Sending HTML e-mail using Email::Stuffer
5. Perl/CGI script with Apache2
6. JSON in Perl
7. Simple Database access using Perl DBI and SQL
8. Reading from LDAP in Perl using Net::LDAP

Common warnings and error messages

1. Global symbol requires explicit package name
2. Variable declaration in Perl
3. Use of uninitialized value
4. Barewords in Perl
5. Name “main::x” used only once: possible typo at …
6. Unknown warnings category
7. Can’t use string (…) as an HASH ref while “strict refs” in use at …
8. Symbolic references in Perl
9. Can’t locate … in @INC
10. Scalar found where operator expected
11. “my” variable masks earlier declaration in same scope
12. Can’t call method … on unblessed reference
13. Argument … isn’t numeric in numeric …
14. Can’t locate object method “…” via package “1” (perhaps you forgot to load “1”?)
15. AUTOLOAD - handling Undefined subroutines
16. Useless use of hash element in void context
17. Useless use of private variable in void context
18. readline() on closed filehandle in Perl
19. Possible precedence issue with control flow operator
20. Scalar value … better written as …
21. substr outside of string at …
22. Have exceeded the maximum number of attempts (1000) to open temp file/dir

Extra articles

1. Multi dimensional arrays in Perl
2. Multi dimensional hashes in Perl
3. Minimal requirement to build a sane CPAN package
4. Statement modifiers: reversed if statements
5. What is autovivification?

From other books

1. Splice to slice and dice arrays in Perl
2. How to improve my Perl program?

Index