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Re^2: Recursion and Such
by djantzen (Priest) on Jan 31, 2005 at 19:19 UTC

    Yup, $depth is probably getting set on the first invocation and never getting updated un subsequent invocations. See this article

    "The dead do not recognize context" -- Kai, Lexx
[reply]
[d/l]
      Yes, this is exactly the problem! The article you sent me to got me on the right path, but I thought it was too brief, or at least it didn't offer enough examples for me to figure out what was happen. You are right, however, the root of my problem was exactly that.

      The following I thought was a very good article on the same thing, although their code is a little cryptic in some places. http://www.serverwatch.com/tutorials/article.php/10825_1128811_1

      Finally The following is the re-written fileDir sub-routine that works just fine (although I think it looks a little ugly to me). 

      sub findDir{
    
    my ($dir, $min, $max) = @_;
    $min_depth = \$min;
    $max_depth = \$max;
    #print "findDir: $dir min: $min_depth max: $max_depth\n";
    $count_files = *count{0};
    
    find( {
        preprocess => \&preprocess,
        wanted => \&wanted,
    }, $dir);
    
    #print "count: $count_files\n";
    
    sub preprocess {
        my $depth = $File::Find::dir =~ tr[/][];
        #print "depth: $depth\n";
        return @_ if $depth < $$max_depth;
        print "depth: $depth max: $$max_depth\n";
        if ($depth == $$max_depth){
            print "greping\n";
            return grep { -df } @_;
        }
        return;
    }
    
    sub wanted {
       
        my $depth = $File::Find::dir =~ tr[/][];
        return if $depth < $$min_depth;
        
        if(!($_ =~ m/^\./)){
            $$count_files++;
        }
    }
    return $$count_files;
    
}

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[reply]
[d/l]
Re^2: Recursion and Such
by Grundle (Scribe) on Jan 31, 2005 at 20:30 UTC
    I thought about using the mkdir() from perl, but my problem is that if a nested directory structure doesn't exist

    i.e. /foo/bar/foobar/

    then the code

    mkdir("/foo/bar/foobar/");

    is going to fail. Therefore I used a system call with the -p option so that any depth of directory will be created without failures.
    As for the recursion bottoming out, just run the code. If it runs inifinitely then it doesn't bottom out. If it exits out, then it has a base case.

    Thanks for the pointers.
[reply]
[d/l]

      Check out File::Path - it has a function mkpath which solves that problem for you. Anything to avoid an unnecessary system call ;-) (Also note that this is part of the standard perl distribution so you can just use it anywhere without having to require extra modules.)

[reply]
        Wow, that is a great suggestion. Thanks for the tip, I definitely prefer not to make direct calls to the system.
[reply]

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