I have written a code in c, it works and now I want to implement it in Monetdb. 

1) should I append the code in /sql/backends/monet5/UDF/udf.c file?
2) I have gone through udf.c, but still not sure how implement my c code there. I do not know C, just wanted to implement simple code. Can anyone help me adapting it to UDF?

I want a function like BAnd(a.chunk, b.chunk), and instead of {"10101011"} in foo and bar, I want values of the columns.

#include<stdio.h>

main (){
    const char foo[] = {"10101011"};
    const char bar[] = {"01110111"};
    int counter;
    float result;
    int strlen = sizeof(foo)/sizeof(foo[0])-1;
    for (int i=0; i < strlen; i++) {
        if (foo[i] == bar[i]) {
            counter++;
        }
    }
    
    result = (float)counter / strlen;
    printf("%d::%d::%f", counter, strlen, result);

    return 0;
}