Perl – How to convert decimal to hexadecimal in Perl

perl

How can I convert a number, $d = 1024, in decimal to 0xFF in hex in Perl?

The d variable needs to be assigned to a different variable and be printed, so for readability I required it to be in hexadecimal format.

1024 in decimal is not 0xFF in hex. Instead, it is 0x400.

You can use sprintf as:

my $hex = sprintf("0x%X", $d);

Here is how to solve it on Mac OS X v10.7 (Lion) or Cygwin (Windows 10):

Add the following lines to your bashrc or bash_profile file on the host machine:

# Setting for the new UTF-8 terminal support in Lion
export LC_CTYPE=en_US.UTF-8
export LC_ALL=en_US.UTF-8

If you are using Z shell (zsh), edit file zshrc:

# Setting for the new UTF-8 terminal support in Lion
LC_CTYPE=en_US.UTF-8
LC_ALL=en_US.UTF-8

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