Heres a good use for closeures. The way File::Find works there are no good way to pass extra arguments into the wanted subroutine without using closeures. So for your example you could do something like this: 
sub Get_Saves {
    my @files;
    #Just a small mod here. Call FileName since it now
    #returns a suitable closeure, and pass in the 
    #reference to @files so that FileName knows
    #where to add stuff.
    @files=find(FileName(\@files),"/usr/local/apache/htdocs/service
+/");
    return  \@files, $#files+1;
}##END Get_Saves

sub FileName {
    my $files_ref=shift; #Use reference to array
    return sub {
       unless (($_ eq "." )or ($_ eq "temp.svd")){
          push @{$files_ref}, $_;
       }
       #removed this since returning anything from the
       #wanted function does not really make any sence(See
       #File::Find)
       #return @files
   }
}

[download]

A few years back a colleuge of mine was horrified of the File::Find module, since you basically had to use "global" variables to be able to pass arguments in to it. I was sure that couldnt be so, but I didnt know/understand closeures at the time. He ended up writing his own find routine, and I twisted my brain for days on how to do this with File::Find.

The solution came to me months later when I learned about closeures. Unfortunately I had quit the company by then, so I couldnt tell him how he had wasted his time reimplementing File::Find. Anyway, I guess the moral is something like:Whenever File::Find doesnt seem to do all you want, start reading about closeures again.

GoldClaw

In reply to Re: Sub in a Sub & Recursion by goldclaw
in thread Sub in a Sub & Recursion by hakkr

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