> -----Original Message----- > From: Theresa Mullin [mailto:[EMAIL PROTECTED]] > Sent: Monday, June 24, 2002 2:30 PM > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: Running Modules > > > Greetings All, > > I have the following code, from which I attempt to call the module > "Test" > #!/usr/local/bin/perl > ### > ### Program name: demo.pl > ### Created By: Theresa Mullin > > require "cgi.lib"; > > ### Include the CGI stuff > use CGI qw(:standard); > > ### Include the database access stuff > use DBI; > > ### Push location of user created packages onto @INC array > push(@INC,"/home/tmullin/perl/libs"); > > use Test; > > ### Force "no buffering" for output > $| = 1; > > > ### Parse the arguments sent in from the browser > &ReadParse(); > > ### Open log file > open DEMO_LOG, ">/home/tmullin/demo_log"||die "unable to open > log file"; > > print DEMO_LOG "Begin processing...\n"; > print DEMO_LOG "array INC: @INC\n"; > print DEMO_LOG "Database selected is: $dbase\n"; > > >
I assume you want $dbase to have the value set below, right? > ...Here is module Test: > > #!/usr/bin/perl Don't need this. The shell will never run Test.pm > > ### Program Name: Test.pm > ### Created By: Theresa Mullin > ### Date: 5/20/02 > > package Test; > Add a "use strict" here. > $dbase = "TEST"; Since I told you to add "use strict", you need: our $dbase = "TEST"; > print "And to all a good night \n"; Modules need to end with a true value, so it's customary to have this as the last line, which is always a true value: 1; > > The code appears to execute, and no error messages are generated. > However, the value of $dbase is never written to the log file. > Any advice you can give would be helpful. The reason is that in Test.pm, you set the value of $Test::dbase, while in your main program you access the value of $main::dbase. So, you have two options: 1. Refer to the variable as $Test::dbase in your main program, or 2. "Export" $dbase to your main package. Perl has a simple mechanism that allows modules like Test.pm to "export" symbols into the calling namespace, such that when you access $dbase, you actually are getting the value of $Test::dbase. To do this, you would add the following lines to Test.pm, typically right after the "package Test" line: require Exporter; our @ISA = qw(Exporter); our @EXPORT = qw($dbase); Now when you "use Test" in your main program, the $dbase symbol will be automatically exported to your namespace and everything will Just Work. n.b. if you are creating a module for use by others, it is now considered "impolite" to unilaterally export symbols like this. The preferred method is to use the @EXPORT_OK array instead of @EXPORT: our @EXPORT_OK = qw($dbase); Now, the symbol will only be exported if explicitly requested on the use line: (in main program) use Test qw($dbase); All the poop on this is in: perldoc Exporter HTH P.S. why use both cgi-lib.pl and CGI? The former is deprecated and the latter should be used exclusively... -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
