Variable length binary number to signed integer representation

I have a variable length text representation of a binary number up to 64 "bits" long. I want to be able to convert this back to a singed integer representation of the number.

This is what I have so far, but a few problems are encountered:

binNum = '11000000'    %for example decimal 192, I want it to be read as -64
typecast(uint64(bin2dec(binNum)),'int64')

issues:

1. the leading '1' is dropped and not read in correctly
2. if appending 1's to the front to fill up the 64 bits maximum, bin2dec only supports 53 bits
3. unit8 cannot be used since binNum can be from 1 bit in size to 64 bits

I am thinking I will need to write my own funciton, but was wondering if there was a built in way to handle this problem

Answer 1

[Walter Roberson]

binNum = '11000000';
bin64 = uint64([repmat(binNum(1), 1, 64-length(binNum)), binNum] - '0')

bin64 = 1×64

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

outu64 = sum(bin64 .* uint64(2).^uint64(63:-1:0), 'native')

outu64 = uint64 18446744073709551552

fprintf('%016x', outu64)

ffffffffffffffc0

outs64 = typecast(outu64, 'int64')

outs64 = int64 -64