pack/unpack - litle endian - 64bit - question

问题

#!/usr/bin/env perl
use warnings;
use 5.012;

my $var = 1 << 31;
say unpack( "B*", pack( "N", $var )  );

# 10000000000000000000000000000000

How can I get with pack/unpack from

my $var = 1 << 63;

an output like this?

# 1000000000000000000000000000000000000000000000000000000000000000

回答1:

say unpack("B*", pack( "Q>", $var ));

The > forces big-endian byte-order on the Q (unsigned 64-bit "quad") type.

来源：https://stackoverflow.com/questions/4672213/pack-unpack-litle-endian-64bit-question