Perl Getting An Error With Refferrer

my $refer = $ENV{HTTP_REFERER}; my $gk1 = substr($str1, -4); if ($gk1 = .swf) { my $antigk = 'gk detected'; } else { my $antigk = $link; } what is wrong with this code? i get

Solution 1:

You probably have this near the top of your index_dl.pm file:

use strict;

This means that you need to declare each variable with my before you use it:

my $str1;

You probably want to declare $antigkbefore your if-else block and maybe you really want:

my $antigk = $link;
if ($gk1 eq '.swf') { $antigk = "gk detected"; } 
else 
{ $antigk = $link; }

Solution 2:

# In this line you store the HTTP referer in the variable $refer
my $refer = $ENV{HTTP_REFERER};

# Then, in this link you take a substring of the variable $str1.
# But you don't have a variable called $str1.
# Perhaps you actually wanted to take a substring of $refer?
my $gk1 = substr($str1, -4); 

# This next line will be a syntax error because you need to quote
# strings (and .swf is a string. This should be '.swf'.
# Also, you are using '='. This is the assignment operator. This
# will set $pgk1 to the value '.swf'. That's not what you want to do.
# You want to compare $pgk1 and '.swf'. For that you need the comparison
# operator - which is 'eq'.
# So this whole line should be:
# if ($gk1 eq '.swf') {
if ($gk1 = .swf) {
  # It's good that you are declaring $antigk using 'my'. But 'my' only
  # works within a code block. So you're setting $antigk here, but the
  # value will be lost as soon as you pass the end of the code block
  # (which is the '}' on the very next line).
  # Better to declare $antigk (with 'my $antigk') before the 'if' statement.
  my $antigk = "gk detected";
} else {
  my $antigk = $link;
}

In general, you are making some very basic programming errors here. I assume that you think you learn best by jumping into a problem and Googling for help. I don't think that approach is working for you. I'd strongly recommend talking a couple of days to work through a beginner Perl book (like "Learning Perl") before continuing with this project.

Solution 3:

Apart of toolic's answer, I guess you have to change those lines:

my $refer = $ENV{HTTP_REFERER};
my $gk1 = substr($str1, -4); 

to these ones:

my $refer = $ENV{HTTP_REFERER};
my $gk1   = substr($refer, -4); 
#                  ^^^^^^