Binary to trinary [duplicate]

Question

The problem

Given a binary number from 0 to 111111 convert it to trinary. (Base 3). Then print the result.

Rules

No using a list of conversions.

Don't cheat

You must use a string as the number

No compressing the input string As I will be testing the code with several different numbers I can't use compressed strings

Notes

By trinary I mean counting in base 3. So 0,1,2,10,11,12,20... ect

Leading zeros will be present 001101

Most important number is on the left.

Example

String input = "110111"
String a = code(input);
print(a);

To win

This is code golf!

Do it correctly and in the smallest size.

Answer 1

Bash 25 bytes

Golfed

bc<<<"ibase=2;obase=3;$1"

Answer 2

JavaScript (ES6), 26 bytes

s=>(+`0b${s}`).toString(3)

Answer 3

Ruby, 97 87 bytes

f=->a{x=0
a.chars.map{|i|x+=x+i.ord%2}
o=x>0?"":?0
(o=(48+x%3).chr+o
x/=3)while x>0
o}

Old version:

def f a
x=0
a.chars.map{|i|x=x+x+i.ord%2}
o=x>0?"":"0"
while x>0
o=(48+x%3).chr+o
x/=3
end
o
end