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
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