How Can I convert Hex to Binary in a perl script

telecom_is_me · 07-02-2008, 01:11 PM

I'm attempting to write a script that will convert a stream of Hex to a stream of binary using Perl.

I've found a number of code examples such as this:

Code:

%h2b = (0 => "0000",
1 => "0001", 2 => "0010", 3 => "0011",
4 => "0100", 5 => "0101", 6 => "0110",
7 => "0111", 8 => "1000", 9 => "1001",
a => "1010", b => "1011", c => "1100",
d => "1101", e => "1110", f => "1111",
);

$hex = "414243";
($binary = $hex) =~ s/(.)/$h2b{lc $1}/g;
print $binary, "\n";

But they are static and seem awfully convoluted to get a result, isn't there a function similar to "bc" at the shell, that can convert a piped "|" input.

0.o · 07-02-2008, 01:18 PM

http://search.cpan.org/~eryq/Convert...vert/BinHex.pm

telecom_is_me · 07-02-2008, 01:24 PM

Quote:

Originally Posted by 0.o

http://search.cpan.org/~eryq/Convert...vert/BinHex.pm

Thanks but that's way past my programing ability, I'm just starting to learn perl.

What I'm trying to do is take an input stream similar to this:

Code:

f6f6f628282801020300
9c3c045f3059edeae18c
8c000000000000000000
0000000055045f3059ed
33ff3700000000000000
d19c3c045f3059edeae1
00000000000000000000
b371aad19c3c045f3059
00000000000000000000

And convert it to it's binary equivalent in the same format.

rjlee · 07-02-2008, 02:20 PM

Guide to perl modules: http://stein.cshl.org/genome_informa.../perl-modules/

ntubski · 07-02-2008, 02:20 PM

Code:

#!/bin/bash
echo -n -e $(tr -d '[:space:]' | sed 's/../\\x&/g')

telecom_is_me · 07-02-2008, 02:51 PM

Quote:

Originally Posted by ntubski

Code:

#!/bin/bash
echo -n -e $(tr -d '[:space:]' | sed 's/../\\x&/g')

That does some interesting stuff but not what I was expecting. Instead I get the following:

Code:

$ cat hex.txt
f6f6f628282801020300
9c3c045f3059edeae18c
8c000000000000000000
0000000055045f3059ed
33ff3700000000000000
d19c3c045f3059edeae1
00000000000000000000
b371aad19c3c045f3059
00000000000000000000

$ cat hex.txt | ./scripts/hex2bin.sh > hexout.txt

$ cat hexout.txt
���(((^A^B^C^@�<^D_0Y��ጌ^@^@^@^@^@^@^@^@^@^@^@^@^@U^D_0Y파3�7^@^@^@^@^@^@^@ќ<^D_0Y휌꜌ᜌ^@^@^@^@^@^@^@^@^@^@�q�ќ<^D_0Y^@^@^@^@^@^@^@^@^@^@

??

telecom_is_me · 07-02-2008, 04:38 PM

Quote:

Originally Posted by ntubski

Code:

#!/bin/bash
echo -n -e $(tr -d '[:space:]' | sed 's/../\\x&/g')

I'm trying to do it slightly more manually as a bash case statement with output like this:

Code:

while read VALUE; do
    case "$VALUE" in
        0)      echo "0000";;
        1)      echo "0001";;
        2)      echo "0010";;
        3)      echo "0011";;
        4)      echo "0100";;
        5)      echo "0101";;
        6)      echo "0110";;
        7)      echo "0111";;
        8)      echo "1000";;
        9)      echo "1001";;
        A)      echo "1010";;
        B)      echo "1011";;
        C)      echo "1100";;
        D)      echo "1101";;
        E)      echo "1110";;
        F)      echo "1111";;
        a)      echo "1010";;
        b)      echo "1011";;
        c)      echo "1100";;
        d)      echo "1101";;
        e)      echo "1110";;
        f)      echo "1111";;
    esac
done

However when I feed it an input like (f5) it reads it literally as the string f5 instead of the individual (f)and(5).

Mr. C. · 07-02-2008, 04:53 PM

Try man od

telecom_is_me · 07-02-2008, 04:54 PM

I got it work! Go me!

The following does the trick:

Code:

#!/usr/bin/perl

$/ = '';

%h2b = (0 => "0000",
1 => "0001", 2 => "0010", 3 => "0011",
4 => "0100", 5 => "0101", 6 => "0110",
7 => "0111", 8 => "1000", 9 => "1001",
a => "1010", b => "1011", c => "1100",
d => "1101", e => "1110", f => "1111",
A => "1010", B => "1011", C => "1100",
D => "1101", E => "1110", F => "1111",
);

while (<>) {
        chomp;
                ($binary = $_) =~ s/(.)/$h2b{lc $1}/g;
                print $binary, "\n";
}

If you input something like:

Code:

f6f6f628282801020300
9c3c045f3059edeae18c
8c000000000000000000
0000000055045f3059ed
33ff3700000000000000
d19c3c045f3059edeae1
00000000000000000000
b371aad19c3c045f3059
00000000000000000000

You get an output of:

Code:

11110110111101101111011000101000001010000010100000000001000000100000001100000000
10011100001111000000010001011111001100000101100111101101111010101110000110001100
10001100000000000000000000000000000000000000000000000000000000000000000000000000
00000000000000000000000000000000010101010000010001011111001100000101100111101101
00110011111111110011011100000000000000000000000000000000000000000000000000000000
11010001100111000011110000000100010111110011000001011001111011011110101011100001
00000000000000000000000000000000000000000000000000000000000000000000000000000000
10110011011100011010101011010001100111000011110000000100010111110011000001011001
00000000000000000000000000000000000000000000000000000000000000000000000000000000

telecom_is_me · 07-02-2008, 05:20 PM

Now if I can figure out a way to do it in reverse I'll be all set.

ntubski · 07-02-2008, 08:38 PM

Quote:

That does some interesting stuff but not what I was expecting.

Yeah, I didn't realize you meant text binary. :P

binary -> hex

Code:

#!/usr/bin/perl

while (<>) {
    chop;
    for (my $i = 0; $i < length($_); $i += 4) {
	my $nibble = '0b'.substr($_, $i, 4);
	printf('%x', oct($nibble));
    }
    print "\n";
}

hex -> binary

Code:

#!/usr/bin/perl
while (<>) {
    chop;
    for (my $i = 0; $i < length($_); $i += 1) {
	printf('%04b', hex(substr($_, $i, 1)))
    }
    print "\n";
}

matthewg42 · 07-02-2008, 08:59 PM

can't you use pack and unpack?

matthewg42 · 07-02-2008, 09:10 PM

Yes, here we go.

Code:

#!/usr/bin/perl

use warnings;
use strict;

foreach my $h (qw(0 1 2 e f 10 11 12 1e 1f 20 30 40 50 100 200 1000)) {
        printf "hex = %4s  binary = %16s\n", $h, hex2bin($h);
}


sub hex2bin {
        my $h = shift;
        my $hlen = length($h);
        my $blen = $hlen * 4;
        return unpack("B$blen", pack("H$hlen", $h));
}

Output:

Code:

hex =    0  binary =             0000
hex =    1  binary =             0001
hex =    2  binary =             0010
hex =    e  binary =             1110
hex =    f  binary =             1111
hex =   10  binary =         00010000
hex =   11  binary =         00010001
hex =   12  binary =         00010010
hex =   1e  binary =         00011110
hex =   1f  binary =         00011111
hex =   20  binary =         00100000
hex =   30  binary =         00110000
hex =   40  binary =         01000000
hex =   50  binary =         01010000
hex =  100  binary =     000100000000
hex =  200  binary =     001000000000
hex = 1000  binary = 0001000000000000

telecom_is_me · 07-02-2008, 09:18 PM

Wow, there's a lot of ways to do it in perl...

Cool, I guess I'll time the processes and see what ones the most time efficient and go from there.

Thanks everyone.

davitz38 · 01-12-2010, 03:36 AM

Hi guys,
For some of you still interested in converting hexadecimal to binary, here's a hex to binary converter. You can make sure you are converting the right way using this tool

David