in reply to Efficiency Question

Why not do something like: 
foreach (keys %$dirs)
{
    next if $config_dirs->{$skip};
    # Do stuff
}
---- Or ----
foreach (keys %$dirs)
{
    next if grep {/^$skip/} keys %$config_dirs;
    # Do stuff
}

[download]
The second is (as far as I can tell) identical to your code. The first assumes that the entries in $config_dirs is string-wise equal to the entries in $dirs. YMMV

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Re: Re: Efficiency Question
by PrimeLord (Pilgrim) on Mar 21, 2002 at 19:37 UTC
    I'm sorry I forgot to address that. The dirs in %dirs will never exactly match the dirs listed in %config_dirs. The config file will only contain high level directories like /home /etc /usr etc. But the %dirs is going to contain things like /usr/local/bin etc. so an exact match won;t be possible.
[reply]
      If you're brave, you can construct a regex which you can bang your various directories against. This can be done quite simply like so:
      my $skip = join ('|', map {quotemeta} keys %$config_dirs);
      This will look something like "/usr/bin|/home|/var" or what have you. Now you can just go and check against this, like dragonchild suggested, but with a slight mod: 
      foreach (keys %$dirs)
{
    next if /^($skip)/;
    # Do stuff
}

      [download]
      Presumably if the value of $skip does not change within your program, you can use the /o option to only "compile once" your regular expression.
[reply]
[d/l]
[select]
      But then if you have /home in the config file, you should not print /home/foo? (I did not understand that too well) If you are going to have only high level directories (and by that I mean subdirectories in /), and the directories you have to decide wether or not to print are subdirectories of these high level ones, then I guess you could strip everything after the second '/' and then make a direct comparaison... 
      sub print_report {
    foreach (keys %$dirs) {
        print BENCHMARK $_;
        m#^/[^/]+/#;
        next if defined $config_dirs->{$&};
        print "$_\n";
    }
}

      [download]
      (I hope I understood the problem correctly)
[reply]
[d/l]

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