http://qs321.pair.com?node_id=368945

erikharrison has asked for the wisdom of the Perl Monks concerning the following question:

It's been awhile, so pardon if this should go in Meditations.

I've been tinkering around with writing a filemanager in Perl for a while. For implementing basic functionality the abstraction that kept coming to me was to see the filesystem as a hash of hashes and scalars. The following tie is a first cut at that.

package Tie::Filesystem; use warnings; use strict; our $DIR_SEP = '/'; sub TIEHASH { my $class = shift; my $root = shift || '/'; bless {root => $root}, $class; } sub FETCH { my $self = shift; my $leaf = shift; my $pathname = $self->{'root'} . $DIR_SEP . $leaf; return undef unless -e $pathname; if (-d $pathname) { my %dir; tie %dir, 'Tie::Filesystem', $pathname; return \%dir; } return $pathname; #in the future, possibly return something useful } sub EXISTS { my $self = shift; my $leaf = shift; return -e ($self-{'root'} . $DIR_SEP . $leaf); } sub FIRSTKEY { my $self = shift; opendir DIR, $self->{'root'} or return undef; $self->{'dir_handle'} = \*DIR; #This magic allows NEXTKEY to work al +most sanely; return readdir DIR; } sub NEXTKEY { my $self = shift; my $dir = $self->{'dir_handle'}; return undef unless $dir; my $entry = readdir $$dir; closedir $$dir unless $entry; return $entry; } 1;

The first bit of Perl I've written in a long while follows. It passes my preliminary test code, but I'm sure it's full of bugs and gotchas. I'm hoping some of y'all could give it a look, and tell me what you think. Specifically, are there any obvious bugs, and what feature would seem useful extensions of the current behavior?

Cheers,
Erik

Light a man a fire, he's warm for a day. Catch a man on fire, and he's warm for the rest of his life. - Terry Pratchet