Chapter Objectives

• Identify and eliminate some problems inherent in CGI scripts.
• Explain and use the undef value.

Topics

• Problems with CGI scripts
• Solutions to these problems
• The value of undefined values

Lab: A CGI script that:

• Dumps the title table from the test_nile database, as in the previous chapter.
• Uses eval:
  • Catch database errors
  • Instead of just dropping dead when they happen
• Tests results with defined():
  • Checks that real handles were returned
  • Instead of just dying if it tries to use one when there is none.

Summary