export dev2='/dev/sdb';
perl -'MDigest::MD5 md5' -ne 'BEGIN{$/=1024};print md5($_)' $dev2

perl -'MDigest::MD5 md5' -ne 'BEGIN{$/=1024};print md5($_)'

perl -'MDigest::MD5 md5_hex' -ne 'BEGIN{$/=1024};print "n$.:, md5_hex($_),"n"'