>perl -wMstrict -le
"my $p = 'ABCDabcdABCDabcd' . pack 'V', 0x3039;
 print qq{'$p'};
 ;;
 my $unp = join '_', unpack 'H32V*', $p;
 print qq{'$unp'};
 ;;
 $p = 'ABCDabcdABCDabcd';
 print qq{'$p'};
 ;;
 $unp = join '_', unpack 'H32V*', $p;
 print qq{'$p'};
"
'ABCDabcdABCDabcd90  '
'41424344616263644142434461626364_12345'
'ABCDabcdABCDabcd'
'ABCDabcdABCDabcd'