use warnings;
use strict;
use IO::Uncompress::Unzip ();

my $filename = 'foo.zip';
my $membername = 'bar.txt';

my $z = IO::Uncompress::Unzip->new($filename, Name=>$membername)
	or die "unzip failed: $IO::Uncompress::Unzip::UnzipError\n";
while (my $line = <$z>) {
	# do something with each $line
}
$z->close;