my $packfmt = "A135A11A6A6A20A8A3A978";
my $outline = pack $packfmt,
   " ", "DATE=${mdy}", ${mdy}, ${hms}, " ", "G1ADP",
   $CLIENT_ID, " ";

# Unpack, trailing blanks preserved
(undef, $DMDY, $mdy, $hms, undef, $CLIENT_ID)
            = unpack $packfmt, $outline;

# Unpack 1: remove trailing blanks (same format, but
# using map to trim the strings):
(undef, $DMDY, $mdy, $hms, undef, $CLIENT_ID)
            = map { s/\s+$//; $_ }
              unpack $packfmt, $outline;

# Unpack 2: remove trailing blanks, different format
my $parsefmt = lc($packfmt);
(undef, $DMDY, $mdy, $hms, undef, $CLIENT_ID)
            = unpack $parsefmt, $outline;