What have you tried so far?

The perlfaq4 lists various conversions, for example from binary to decimal and from decimal to hexadecimal. Why don't you combine those two steps to form a direct conversion from binary to hexadecimal?

I found the answers by using

perldoc -q convert
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That's a totally pointless requirement, but the following does achieve it:

$hex = sprintf('%X', oct("0b$bin"));
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oct converts the binary representation of the number to a number, then sprintf '%X' converts it to its hex representation. It's never represented in decimal.

Update: Or maybe you're actually interested in converting bytes to their hex representation:

$hex = sprintf('%02X', ord($byte));
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Another snippet for your perusal:

#!/usr/bin/perl
use warnings;
use strict;

my $binary = '11101010101010101010101010101010';
my $int = unpack("N", pack("B32", substr("0" x 32 . $binary, -32)));
my $hex = sprintf("%x", $int );
print $hex,"\n";
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Hi zentara and all, Thanx for the info. I got it done very easily using pack and unpack as suggested by zentara. Rgds, Kiran Polu

THanks Ikigami . I was looking everywhere for that.

this function works only for 32 bits, this will work for any binary length sub b2h { my $num=shift; my $WIDTH=32; my $index=length($num)-$WIDTH; print "index= $index\n"; my $hex=""; do { my $width=$WIDTH; if ($index<0) { $width+=$index; $index=0; } $cut_string=substr($num,$index,$width); print "index is $index width is $width Cut String is $cut_string\n"; $hex= sprintf('%X', oct("0b$cut_string")). $hex; $index-=$WIDTH; } while ($index>(-1*$WIDTH)); return $hex; }

Since the code Does What I Want (works even for bit widths > 32), I have made it readable by using perltidy. I have also made it strict and removed the print statements:

use warnings FATAL => 'all';
use strict;

for (
        qw(
            00
            1010
            1110
            010001
            01101011
        ),
        '1' x 33,
        '0101' x 16
) {
    my $h = b2h($_);
    print "$_ $h width=", length($_), "\n";
}
exit;


sub b2h {
    my $num   = shift;
    my $WIDTH = 32;
    my $index = length($num) - $WIDTH;
    my $hex = '';
    do {
        my $width = $WIDTH;
        if ($index < 0) {
            $width += $index;
            $index = 0;
        }
        my $cut_string = substr($num, $index, $width);
        $hex = sprintf('%X', oct("0b$cut_string")) . $hex;
        $index -= $WIDTH;
    } while ($index > (-1 * $WIDTH));
    return $hex;
}

__END__

Output:

00 0 width=2
1010 A width=4
1110 E width=4
010001 11 width=6
01101011 6B width=8
111111111111111111111111111111111 1FFFFFFFF width=33
0101010101010101010101010101010101010101010101010101010101010101 55555
+55555555555 width=64
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I have also been attempting to implement this with pack and unpack, to no avail.

You don't even need perl for this one (at least on a Unix / Cygwin box):

od -t x1 input_file

...roboticus