What Is The Issue With This Cgi/html/perl Program?

I am using XAMMP Apache Server. There is a text file named 'animal.txt' containing the name of an animal on each line, with a basic description. I am trying to write a Perl progra

Solution 1:

Several issues here, but the crux of the matter is this code.

@animals = (<IN>);
$item = param;
foreach $line (<IN>) {
    if ($line =~ /$item/) {
        print"$item";
    }
}

Let's look at each line in turn:

@animals = (<IN>);

This reads all of the data from IN into the array @animals. It also leaves IN's file pointer at the end of the file. Any further attempts to read data from IN will fail.

$item = param;

If you call param with no arguments, you get a list of the parameter names that were found in the CGI request. As you're assigning this list to a scalar value, this behaviour changes and you'll get the number of parameters. In your system this will always be 1. So $item contains the value 1.

foreach $line (<IN>) {

Remember how you read all of the data from IN a couple of lines back? Well you're trying to read more data from it here. And that's not going to work. I think you probably wanted @animals here, not <IN>. Currently your foreach is never executed as on the first iteration the call to <IN> returns undef - which is false.

if ($line =~ /$item/) {

Let's assume that you've replaced <IN> with @animals in your foreach loop - so that the loop body is actually executed. This still isn't doing what you wanted. Remember that $item contains 1 rather than the name of an animal to search for. And I doubt that you have an animal called "1".

What you probably want is something more like this:

my $animal = param('Search');
while (<IN>) {
    printif /$animal/;
}

I'd also point out that learning CGI in 2014 is pretty ridiculous. You would be far better off looking at a simple Perl web framework like Web::Simple or Dancer.

Solution 2:

I think your problem is

$item = param;

Which is putting the number of parameters in your form, in this case 2, into $item. I doubt you have an animal named 2

Change it to

$item = param('Search');