Your code looks pretty good. use strit warnings and diagnostics or die is worth a read RE benefits of strict. foreach and for are synonyms. You use aliasing to $_ in one loop and a my $var in another. This is inconsistent but it makes for easier to read code to write for my $whatever (@widgets) {} as your code becomes more self documenting, especially if the contents of @widgets is not immediately apparent. This loop structure:
$num_domains = scalar @domains;
while ($num_domains > '0') { # Start Loopy Code
[blah]
my $new_domain = shift @domains;
[blah]
$num_domains = scalar @domains; # get the size of array
}
is pretty obtuse to me. while loops are fine but they will also go infinite if you don't satisfy the condition (easy to do). All you really need is a simple
for ( 0 .. $#@domains ) {
# do stuff
}
# or
for my $root_domain ( @domains ) {
# blah
push @domains, @new_domains;
}
The second code snippet is nifty because if you say extract the links from a page and then add the domains to @domains the @domains list gets longer and....you have an instant spider. Without using recursion per se. You can use this iterating over a list/adding to the list in the loop technique to 'recurse' virtually any structure you like. There is an example at Link Checker FWIW that will spider a website. You can also walk a directory tree in a few lines with:
my $root = 'd:/perl/';
my ( @dirs, @fails, @files);
@dirs = ( $root );
for my $dir ( @dirs ) {
opendir DIR, $dir or die $!;#do { push @fails, $dir; next };
while ( $_ = readdir DIR ) {
next if -s "$dir/$_";
do{ push @dirs, "$dir/$_"; next } if -d "$dir/$_"
and not m/^\.\.?$/;
do{ push @files, "$dir/$_"; next } if -f "$dir/$_";
}
}
print "$_\n" for @dirs;
Sure you can use File::Find but this is short, sweet and quite a bit faster.
cheers
tachyon
s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print
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