Re: Bit by a Hex String

Here's a Math::BigInt solution.

#!/usr/bin/perl

use strict;
use warnings;

use Math::BigInt;

$_ = "DEADBEEFBABEFACE1234567890";

my $num = Math::BigInt -> new (0);

# Convert the number to a Math::Int decimal number.
while (length) {
    my $chunk = substr $_, 0, 4, "";
    $num *= 2 ** (4 * length $chunk);
    $num  += hex $chunk;
}

# Multiply by 2, add 1.
$num *= 2;
$num += 1;

# Convert the Math::BigInt number to hex.
my @a;
while ($num) {
    push @a => sprintf "%X" => $num % 16;
    $num /= 16;
}
my $new = join "" => @a;

print $new, "\n";
[download]

And here's an Inline::BC solution:

#!/usr/bin/perl

use strict;
use warnings;

use Inline 'BC';

print x("DEADBEEFBABEFACE1234567890");

__DATA__
__BC__
ibase = 16
obase = 10
define x (a) {
    return (a * 2 + 1)
}
[download]

Abigail

Comment on Re: Bit by a Hex String Select or Download Code

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Re: Re: Bit by a Hex String by abitkin (Monk) on Aug 29, 2003 at 15:29 UTC
Okay, first I need to say, I love your BC solution. It's simple, and elegant. That being said I did some playing around with BigInt, so here's the code I came up with: `sub shift_bs{ $add = shift; $source = shift; $num1=Math::BigInt->new("0x".$source); $num1->blsft(1); $num1+=$add; $temp = $num1->as_hex(); $temp =~ /0x(.*)/; return $1; }` [download] Yeah, the $add is a legacy thing, but that's okay. I want to thank you especially, because you went to quite a bit of work to come up with that code. == Kwyjibo. A big, dumb, balding North American ape. With no chin.	[reply] [d/l]
Re: Bit by a Hex String by Abigail-II (Bishop) on Aug 29, 2003 at 15:45 UTC
`$num1=Math::BigInt->new("0x".$source);` [download] Ah, I didn't know you could do that. The Math::BigInt manual page says: `Input Input values to these routines may be either Math::Big- Int objects or strings of the form "/^[+-]?[\d]+\.?[\d]E?[+-]?[\d]$/".` [download] Abigail	[reply] [d/l] [select]
Re: Re: Bit by a Hex String by abitkin (Monk) on Aug 29, 2003 at 15:52 UTC
Neither did I I only tried it after seeing this in the documentation: `Examples for converting: my $x = Math::BigInt->new('0b1'.'01' x 123); print "bin: ",$x->as_bin()," hex:",$x->as_hex()," dec: ",$x,"\n";` [download] == Kwyjibo. A big, dumb, balding North American ape. With no chin.	[reply] [d/l]