Converting string of 1s and 0s into binary value

Question

I'm trying to convert an incoming sting of 1s and 0s from stdin into their respective binary values (where a string such as "11110111" would be converted to 0xF7). This seems pretty trivial but I don't want to reinvent the wheel so I'm wondering if there's anything in the C/C++ standard libs that can already perform such an operation?

Answer 1

#include <stdio.h>
#include <stdlib.h>

int main(void) {
    char * ptr;
    long parsed = strtol("11110111", & ptr, 2);
    printf("%lX\n", parsed);
    return EXIT_SUCCESS;
}

For larger numbers, there as a long long version, strtoll.

Answer 2

You can use std::bitset (if then length of your bits is known at compile time)
Though with some program you could break it up into chunks and combine.

#include <bitset>
#include <iostream>

int main()
{
    std::bitset<5>  x(std::string("01011"));

    std::cout << x << ":" << x.to_ulong() << std::endl;
}

Answer 3

You can use strtol

char string[] = "1101110100110100100000";
char * end;
long int value = strtol (string,&end,2);

Answer 4

You can use Boost Dynamic Bitset:

boost::dynamic_bitset<>  x(std::string("01011"));
std::cout << x << ":" << x.to_ulong() << std::endl;

Answer 5

I've wrote a few functions for this and licensed under LGPL. Can be found here.