How do I convert a decimal number to a hex string in Perl?

Question

How do I convert a decimal number to a hex string in Perl?

For example, I would like to convert 2001 into "0x07" and "0xD1".

Answer 1

This works for that case:

($x,$y) = map { "0x$_" } 
          sprintf("%04X\n", 2001) =~ /(..)(..)/; 

But I wonder what you're really trying to do. If you're trying to get UTF-16, this isn't the way you want to do that.

If you're trying to figure out the layout of packed binary data, then you should be using unpack . The "C4" format would work for a 4-byte integer.

$int = 2001;
$bint = pack("N", $int);
@octets = unpack("C4", $bint);
printf "%02X " x 4 . "\n", @octets;
# prints: 00 00 07 D1

For some purposes, you can use printf 's vector print feature:

printf "%v02X\n", pack("N", 2001);
# prints: 00.00.07.D1

printf "%v02X\n", 255.255.255.240;
# prints: FF.FF.FF.F0

Answer 2

我不确定您要使用的确切格式，但是转换为十六进制的一种方法是：

sprintf("%x", 2001)