Course Overview
Perl for System Administrators is an introductory-level hands-on Perl training course that course leads the student from the basics of writing and running Perl scripts to more advanced features such as file operations, report writing, the use of regular expressions, working with binary data files, and using the extensive functionality of the standard Perl library. Once these skills are mastered, this intensive course moves into practical tools for automating Linux/Unix system administration. Students will learn how to convert existing bash scripts to Perl, and create new scripts that will safely and securely automate system administration tasks.
Course Topics Covered: Students will learn and explore:
- Variables and constants
- Conditions and iterations
- Arrays and hashes
- Working with Files
- Formatting output
- Executing programs
- References and data structures
- Working with files and directories
- Regular Expressions
- Subroutines
- Monitoring processes
- Shortcuts and Defaults
- Using the Standard Library
Course Objectives
Throughout the course students will be led through a series of progressively advanced topics, where each topic consists of lecture, group discussion, comprehensive hands-on lab exercises, and lab review. This course is “skills-centric”, designed to train attendees in core Perl scripting tasks appropriate for systems administrators.
Working within in an engaging, hands-on learning environment, guided by our expert practitioner, students will learn to:
- Create a working script that gets input from the command line, the keyboard, or a file
- Use arrays to store and process data from files
- Create formatted reports
- Launch external programs
- Interface with bash scripts
- Understand and use regular expressions
- Use the appropriate types of variables and data structures
- Refactor duplicate code into subroutines and modules
- Know what is available in the standard library
Course Prerequisites
This course is appropriate for anyone who wants to automate and simplify common system administration tasks with Perl.
Students should already have a working, user-level knowledge of a Unix-like operating system (Linux, Solaris, Mac OS, e.g.). While not mandatory, basic skills with at least one other programming language are desirable.
Course Agenda
Session: Getting Started
- What is Perl?
- Structure of a Perl program
- Running a Perl script
- Checking syntax and warnings
- Execution of scripts under Unix and Windows
Session: Basic Data and I/O
- Numeric and Text literals
- Math operators and expressions
- Scalar variables
- Default values
- Writing to standard output
- Command line arguments
- Reading from the standard input
Session: Logic and Loops
- About flow control
- The if statement and Boolean values
- Using unless and elsif
- Statement modifiers
- warn() and die()
- The conditional construct
- Using while loop and its variants
- Using the for loop
- Exiting from loops
Session: Lists and Arrays
- The list data type
- Accessing array elements
- Creating arrays
- List interpolation
- Arrays and memory
- Counting elements
- Iterating through an array
- List evaluation
- Slices and ranges
Session: Reading and writing text files
- File I/O Overview
- Opening a file
- Reading text files
- Writing to a text file
- Arrays and file I/O
- Using the <> operator
Session: List functions
- Growing and shrinking arrays
- The split() function
- Splitting on whitespace
- Assigning to literal lists
- The join() function
- The sort() function
- Alternate sort keys
- Reversing an array
Session: Formatting output
- Report formatting overview
- Defining report formats
- The write() function
Session: Hashes
- Hash overview
- Creating hashes
- Hash attributes
- Traversing a hash
- Testing for existence of elements
- Deleting hash elements
Session: References and data structures
- What is a reference?
- The two ways to create references
- References to existing data
- References to anonymous data
- Dereferencing scalar, array, and hash references
- Dereferencing elements of arrays and hashes
- Multidimensional arrays and other data structures
- Sorting data structures
Session: Text and Regular Expressions
- String length
- String functions and operators
- Quoting in Perl
- Regular expressions
- Advanced pattern matching and substitution
Session: Subroutines and variable scope
- Understanding packages
- Package and Lexical variables
- Localizing builtin variables
- Declaring and calling subroutines
- Calling subroutines
- Passing parameters and returning values
Session: Managing files and directories
- File attributes
- Reading a directory
- Using File::Find
- Permissions
- Copying and moving files
- Renaming and deleting files and directories
- File test operators
Session: Sys Admin Part 1
- Environment variables
- Running external programs
- User identification
- Trapping signals
- Backtick operator
- Time of day
Session: Shortcuts and defaults
- Understanding $_
- shift() with no array specified
- Text file processing
- Using grep() and Using map()
- Command-line options for file processing
Session: Using Modules
- Perl modules
- Use vs. require
- A quick tour
- Bundled libraries and modules
- Downloading and installing from CPAN
- Case study: Using Getopt::Long
Session: Creating Modules
- Review of subroutines
- Understanding my () and local ()
- Packages and the symbol table
- Mechanics of module creation
- Exporting subroutines and data
- Using BEGIN and END
- Good module design
Session: Classes
- Perl's approach to Classes
- Understanding bless
- Constructors
- Methods
- Properties
- Inheritance
Session: Exception handling
- Simple exception handling
- Trapping exceptions
- Using Carp, Croak, and Cluck
- Raising exceptions
Session: Sys Admin Part 2
- Monitoring files
- Accessing syslog
- Network information
- User management
OPTIONAL ITEMS | As time permits:
Session: Network Tools
- Copying files across the network
- Remote login
- Grabbing data from the Web
Session: Serializing Data
- Available tools
- Storable
- JSON
Session: Enterprise Development
- Coding standards
- Source code tools
- Core modules
- Saving time with module-starter
- Documenting with POD
- Benchmarking and Profiling
- Unit testing
- Distributing and installing modules
Course Materials
Our course materials include more than a simple slideshow presentation handout. Each student will receive a comprehensive course Student Guide, complete with detailed course notes, code samples, software tutorials, diagrams and related reference materials and links. Our courses also include detailed our Student Workbook, with step by step hands-on lab instructions and code samples, clearly illustrated for users to complete hands-on work in class, and to revisit to review or refresh skills at any time. Students will also receive the course set up files and project code needed for the hands on work.