EE-WBC PERL Programming Examples

• Introduction
  • Hello World program
  • Variables and variable extrapolation in "" strings
  • Is it a number or string variable?
  • Side track: ++ used for numbers and strings
  • Escape sequences (backslash inside quoted string)
  • Reading input line by line
  • Splitting a line into multiple data items
• Conditional and repetition statements
  • if and other conditional statements
  • for and other repetition statements
  • do used for pseudo-construct statements
• Lists, arrays and hash tables
  • Simple array operations
  • Printing array variables inside double quotes
  • Hash-table Arrays as look-up tables
  • Organizing access to the hash-tables
  • Yet another use of hash tables - for counting
  • Array acess using foreach
  • 2D arrays
  • Hash-table of Hash-tables
  • Array of hash-tables, hash-table of arrays, and higher dimensions left to students' exrecise
• Sorting
  • Sorting arrays
  • Sorting hash tables
• Directory and File Access, Pipes
  • Accessing files
  • Testing files
  • Checking file information
  • Printing content of a directory
  • Various data processing modes:
    • Ask the user
    • The command line arguments
    • The "pipeline" approach
      to run: perl -w p_file_07.pl <fin_name.ext >fout_name.ext
  • Reading output produced by another program
  • Running another program and simulating the keyboard input
  • Recursive cleaning temporary directory
  • ASCII and BINary reading from files
  • Unpack BINary files
• Regular expressions
  • Answer yes or no - no regex
  • Answer yes or no - with regex
  • Matching and extracting input: price
  • Matching and extracting input: time
  • Summary of commands
  • Discussion on matching input: price
  • Discussion on matching input: time
  • Multiple extractions from the same data
  • Translate (global multiple cases of single character search/replace)
  • Search and Replace: introduction
  • Search and Replace: Repeated the-the clean up
  • Search and Replace: Get rid of any repeated repeated words
• Functions
  • Calling a function - how to call a function and return a result
  • Recursive function call - factorial function
  • Passing parameters - different ways
  • Passing parameters - passing arrays as multiple parameters
  • Passing parameters - passing arrays as arrays (by reference)
  • Passing parameters - passing and returning arrays as arrays (by reference)
  • Passing parameters - passing a hash array by reference
• Real life complexity data manipulation
  • Getting data from a text configuration file into a hash array   the sample configuration file
  • Sorting applied to log file statistics
  • Time and date formatting
  • Verify an email address
  • Simple and yet thorough verification of email address
  • Download a Web page
• Internet and socket connections
  • TCP Client socket connection
  • TCP Server socket connection
  • Looking up IP addresses   was too compact to follow?  
  • Efficient way to lookup IP addresses when you have hundreds of them to process
  • Check the Internet connection with Ping
  • Advanced DNS lookup (requires addition of DNS.pm)
  • Send e-mail (requires addition of Sender.pm)
• Scalable TCP server that utilizes multithreading
  • Multithreading for scalability
• Interesting libraries that need to be uploaded using ppm first
  • Weather::Underground.pm
  • PERL-API2.pm
• Graphics generated in PERL (requires GD.pm - Windows and Linux only, sorry!)
  • How to check or install GD and GD::Graph libraries
  • Generate and save a graph

Source code listings were prepared using Code2HTML, courtesy of Peter Palfrader.