Fundamentals of CGI Programming Using Perl

1. Fundamentals of CGI Programming Using Perl

2. Lesson 1:ApplicationDevelopment Fundamentals

3. Objectives • Explain the application development process • Distinguish among various application development environments • Identify common application development platforms • Clarify various communication protocols • Determine when to use client-side or server-side scripting

4. Define a need for a solution Analyze the requirements Create an implementation plan and perform top-level design Perform in-depth design Create the application Test the system Deploy the system Maintain the system The ApplicationDevelopment Process

5. Platforms,Languages and Protocols • Development platforms • Server-side development technologies • Client-side development technologies • Communication protocols

6. Client-Side vs. Server-Side Scripting • Performance issues • Security risks

7. HypertextTransfer Protocol • Passing information with HTTP • HTTP methods

8. Summary • Explain the application development process • Distinguish among various application development environments • Identify common application development platforms • Clarify various communication protocols • Determine when to use client-side or server-side scripting

9. Lesson 2:Introduction to CGI and Perl

10. Objectives • Explain how the Common Gateway Interface works • Describe the GET and POST methods • Describe the benefits of CGI • Describe the benefits of choosing Perl as your CGI scripting language

11. Web Architecture Overview • Browser, server and script interaction • Common Gateway Interface

12. What Is CGI? • Common • Supported on almost every platform • Gateway • Gate or conduit that connects clients and servers or server programs • Interface • The manner in which the gateway is used

13. Why Use CGI? • Two-directional communication • Storage of user-entered data • Portability of code • Browser independence

14. What Is Perl? • Practical Extraction Report Language

15. Why Use Perl? • Free license • Smooth installation • Pre-existing programs • Text and file processing capabilities • Strong points from other languages

16. Summary • Explain how the Common Gateway Interface works • Describe the GET and POST methods • Describe the benefits of CGI • Describe the benefits of choosing Perl as your CGI scripting language

17. Lesson 3:Creating a Simple Script

18. Objectives • Discuss the advantages and disadvantages of client-side and server-side scripts • Use scalar variables • Print HTML to the browser using the print statement

19. Key Concepts and Syntax • Client-side versus server-side scripting • Scalar variables in Perl • Built-in functions • Single and double quotation marks • Using variables in strings • User-defined functions

20. Key Concepts and Syntax(cont’d) • Printing HTML from a Perl script • Including HTML after the _END_ keyword • Printing HTML using print <<ANYWORD • Printing HTML from a file

21. Summary • Discuss the advantages and disadvantages of client-side and server-side scripts • Use scalar variables • Print HTML to the browser using the print statement

22. Lesson 4:Perl Fundamentals

23. Objectives • Use CGI.pm to examine environment variables • Use Perl arrays and associative arrays • Define list and scalar context • Use pattern matching operators • Write if statements • Create loops

24. Accessing Environment Variables • Environment variables are stored in an associative array

25. Using CGI.pm to Access Environment Variables • Simpler CGI.pm syntax • Environment access methods

26. If Statement • Used exactly as it is used in JavaScript • Can also be used in a unique way at the end of any statement

27. Logical Expressions • Numeric and string operators

28. Pattern Matching • Pattern matching operator

29. Perl Arrays • Holds a list of scalars (numbers of strings) • List context versus scalar context • Initializing scalar variables from an array

30. Passing Values to Functions • Values that are passed to functions are held in arrays

31. Associative Arrays • Converting associative arrays to arrays • Using join with arrays and associative arrays • Using split with arrays

32. Loops • The while loop • The next and last statements • The for loop • The foreach loop • The sort function

33. Summary • Use CGI.pm to examine environment variables • Use Perl arrays and associative arrays • Define list and scalar context • Use pattern matching operators • Write if statements • Create loops

34. Lesson 5:Perl File Input and Output Capabilities

35. Objectives • Open and close files from within scripts • Read and write to sequential files • Read and write to random-access files • Define file modes • Use the diamond operator in scalar and list contexts • Use file tests in conditional statements

36. File IO Using File Handles • The unless statement • The die statement and the | | operator • The && operator

37. File Modes • Reading a file • Writing to a file • Appending to a file • Reading and writing to a random-access file

38. Using Files in Scripts • Writing to a file • Reading from a file using the diamond operator <> • Reading from a file using the read function • Reading and writing to a random-access file • The seek function

39. Creating a Hit Counter • Every time a page is called, a counter reads and increments the number in the file, and stores it back to the file

40. Summary • Open and close files from within scripts • Read and write to sequential files • Read and write to random-access files • Define file modes • Use the diamond operator in scalar and list contexts • Use file tests in conditional statements

41. Lesson 6:Controlling Processing and Output

42. Objectives • Use the HTML form generation methods of CGI.pm to create HTML pages • Use the param method to retrieve form values • Create a dual-mode form that accepts and generates data depending on how it is accessed • Validate form data and print a missing fields page • Test Perl scripts in offline mode

43. Incorporating HTML into Perl Using CGI.pm • Methods of CGI.pm include • start_html • end_html • startform A,B,C • endform • submit A • textfield A,B,C,D • button A,B • hidden A,B • header A

44. Using CGI.pm to Access Form Data • The POST method • Using CGI.pm for GET or POST

45. ProcessingUser-Entered Data • Using the ReadParse method

46. Using One File to Createand Process an HTML Form • Perl scripts can operate in two modes • Called from a hyperlink • Called from a form submission

47. Using Perl toValidate Form Input • Perl scripts commonly validate form data: • Before saving the data • Before processing the data

48. Summary • Use the HTML form generation methods of CGI.pm to create HTML pages • Use the param method to retrieve form values • Create a dual-mode form that accepts and generates data depending on how it is accessed • Validate form data and print a missing fields page • Test Perl scripts in offline mode

49. Lesson 7:Saving User-Supplied Data to a File

50. Objectives • Use the named parameters syntax for CGI.pm methods • Save data to a file in a tab-delimited format • Save data to a file using the save method of the CGI.pm module • Delete and append name-value pairs • Use the substitution pattern-matching operator • Use the &_ variable to simplify scripts