First, don't combine system() and backticks, as has been explained.

#!/usr/bin/perl -w
$file = 'index.php';
system("cat $file")
    && die "System call failure: $!\n";
print "\n";
[download]

Second, always assume the system call will fail at some time and add an error printout using die or Carp. UN!X System calls use the opposite return result convention to regular perl calls like open(), that's why && rather than the more-usual or.

Update: Also, you can do this without spawning an extra shell by separating the words of the system call:

system('cat', "file") && ..
[download]