copy an array in c

I have a function, it accepts a char**, what is the quickest and most efficient way of making a local copy of the array in the function scope?

That is, i have , for example:

void funk(char **x){

char **b;

/*How do i make a separate copy of x to b?*/
}

Take pity on me internets, I'm a noob :) Thanks.

Answer to what?

It's kind of pointless arguing about null-terminated strings in C. Want to use the standard libraries? You don't really have a choice _but_ to use them. Don't want null-terminated strings? Roll your own string API, and be prepared to not be able to pass your custom strings to the standard library system functions which expect them.

>>41
See post >>42 for the question.

Copying arrays? Forget it, it's NP-Complete.

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// assuming x is a null terminated array of null terminated strings
// untested
void funk(char **x) {
    // calculate length of x
    size_t len;
    for (len = 0; x[len]; ++len);
    // allocate copy
    char **copy = malloc((len + 1) * sizeof(*x));
    // copy over strings
    for (size_t i = 0; i < len; ++i) {
        copy[i] = malloc(strlen(x[i]));
        strcpy(copy[i], x[i]);
    }
    // add null terminator
    copy[len] = 0;
}

>>51

I forgot nulls on strings


// assuming x is a null terminated array of null terminated strings
// untested
void funk(char **x) {
    // calculate length of x
    size_t len;
    for (len = 0; x[len]; ++len);
    // allocate copy
    char **copy = malloc((len + 1) * sizeof(*x));
    // copy over strings
    for (size_t i = 0; i < len; ++i) {
        size_t _len = strlen(x[i]);
        copy[i] = malloc(_len + 1);
        strcpy(copy[i], x[i]);
        copy[_len] = 0;
    }
    // add null terminator
    copy[len] = 0;
}

>>52

oops copy[_len]...


// assuming x is a null terminated array of null terminated strings
// untested
void funk(char **x) {
    // calculate length of x
    size_t len;
    for (len = 0; x[len]; ++len);
    // allocate copy
    char **copy = malloc((len + 1) * sizeof(*x));
    // copy over strings
    for (size_t i = 0; i < len; ++i) {
        size_t _len = strlen(x[i]);
        copy[i] = malloc(_len + 1);
        strcpy(copy[i], x[i]);
        copy[i][_len] = 0;
    }
    // add null terminator
    copy[len] = 0;
}

>>53

oh strcpy copys over null terminated so i need to change this again.


// assuming x is a null terminated array of null terminated strings
// untested
void funk(char **x) {
    // calculate length of x
    size_t len;
    for (len = 0; x[len]; ++len);
    // allocate copy
    char **copy = malloc((len + 1) * sizeof(*x));
    // copy over strings
    for (size_t i = 0; i < len; ++i) {
        size_t _len = strlen(x[i]);
        copy[i] = malloc(_len + 1);
        strcpy(copy[i], x[i]);
    }
    // add null terminator
    copy[len] = 0;
}