1

I have a base-6 number generated by rolling a physical six-sided dice and want to convert it into base-2 / binary.

Are there built-in commands or programs that can do that for me?

If not, what is the manual way of converting the numbers?

Jeff Schaller
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bmvanity8723
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3 Answers3

2

Like Jeff hints in the comments, you can use bc for base conversion. With regard to physical dice, the digits are usually 1 to 6, while bc (and maths) will need digits 0 to 5, so you need to do something about that, either manually, or with something like tr.

For example, this function would map 111 -> 0, 112 -> 1, 121 -> 6 etc.:

f() { 
    echo "obase=10; ibase=6; $(echo $1 | tr 1-6 0-5)" | bc;
}

The output is in decimal, you can change that by changing the value of obase above. Or you can use the decimal number for other arithmetic.

ilkkachu
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Manually

Set total to 0
Repeat until no more roles:
  multiply total by 6 #this has no effect the first time around the loop
  role dice
  add (number on dice -1) to total

Software

See other answers and comments

Community
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ctrl-alt-delor
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There are a couple of POSIX tools to convert from base 6 to base 2.

However, the symbols in a dice are 1 2 3 4 5 6 while a base-6 integer should use only the symbols 0 1 2 3 4 5, there is a difference of 1. Any tool used must take that into account. For a single digit, that is not a big issue:

The simplest is bc (or dc). The conversion of a single digit could be done as:

digit=5; echo "n=$digit - 1; obase=2; n" | bc

But for several rolls in one string, like 31256 it needs to be input as a decimal number and subtract 1 from each digit (11111 in this case) and then re-input as a base-6 number.

$ echo "ibase=6; obase=2; $(echo "31256-11111" | bc)" | bc
101001100001

Or, as text, you can convert every 6 to 5, every 5 to 4, etc.:

$ echo "ibase=6; obase=2; $(echo "31256" | tr 123456 012345)" | bc
101001100001

Another option is awk:

awk -v n=31256 '
            function roll2dec(str,    ret, i, c){
        for (i = 1; i <= length(str); i++) {
                    c = substr(str, i, 1)
                ret = ret * 6 + index("23456", c)
            }
            return ret
        }
            function dec2bin(dec,    bin){
                while (dec>0){ 
                    bin = dec%2 bin;
                    dec=int(dec/2) 
                };
                return bin
            }
  BEGIN{

  print dec2bin(roll2dec(n))

  }'

101001100001