A Diumenge 22 Octubre 2006 18:38, Gav Ford va escriure:
> Hello,
>
> I'm just starting out here and hope someone can help, I think I've
> gotten all confused over how to read values from a Hash.
>
> Or it could be I've just got totally the wrong end of the stick.
>
> The data in question is the album art attached to an MP3 file. I'm
> trying to read it from the MP3 and save it as a file. I'm using a
> module I got from cpan called MP3::Tag.
>
> Here is my program so far, see if this makes things clearer.
>
>
>
> #!/usr/bin/perl -w
>
> use MP3::Tag;
>
> chomp ($filename = $ARGV[0]);
>
> print "Getting art for $filename \n";
>
> $mp3 = MP3::Tag->new($filename);
>
> $mp3->get_tags();
>
> $tagdata = $mp3->{ID3v2} if exists $mp3->{ID3v2};
>
> $title = ($tagdata->get_frame("TIT2"));
> $artist = ($tagdata->get_frame("TPE1"));
> $album = ($tagdata->get_frame("TALB"));
>
> print "This is $title by $artist\, from the album $album.\n";
> print "So I'll call the artwork file: $album\.jpg \n";
>
>
> %artinfo = $tagdata->get_frame("PIC"); # doesn't seem to work?
>
> $mp3->close();
>
> $art = $artinfo{"_Data"}; # or it could fault
>
>
> # write the art to file
> open ARTWORK, ">$album.jpg" or die "File $album.jpg could not be
> opened.\n"; print ARTWORK $art;
> close ARTWORK;
>
>
>
> Things seem fine, It can read the artist, album and track names and all
> this goes well. The documentation tells me that get->frame() will
> return simple strings I can use and this is so.
>
> For PIC it should return a Hash containing keys called 'Image Format',
> 'Picture Type', '_Data', 'Description' and 'encoding' and a string
>
> The data I want is attached to the key '_Data'.
>
> However it seems to return two strings 'HASH(0x8356294)' and 'Attached
> picture' when I read it to an array or a set of comma separated scalars.
>
> I feel that the value HASH(0x8356294) is somehow a clue, but I can't
> figure out how to access what I want from it.
>
> Please could somebody point me in the right direction?
>
> -Gav
to assing values to a (key of ) hash do as: $hash_name{$key_name} =
$value_name. to read same pair key/value use each function into a while loop:
while (($key_name, $value_name)) = each %hash_name). sign % indicates the
whole hash.
cheers,
--
Xavier Mas
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
<http://learn.perl.org/> <http://learn.perl.org/first-response>
