Copying a subarray from an array of substrings in c

Question

I'm working on a function which is supposed to take an array of elements defined by a struct.

typedef struct word{
    char word[100];
    double weight;
} word;

The function takes in a pointer, word *words and creates a subarray which includes only the word elements which are above a certain value n.

I want to use strncpy for this, so I wrote the following:

char dest[numwords]; //the number of words in the array
strncpy(dest, *words, numwords -n);

However, I don't think this code will create the subarray I desire. For example, if the array is {"word1", "word2", "word3", "word4", "word5"} and I want the sub array to be {"word4", "word5"}, using the code above, numwords - n = 4-2, which will give me {"word1", "word2", "word3"} instead.

How do I resolve this? Thanks.

@shari It is unclear where the strings are stored. Are they all stored in the data member word of an object of the type word? Or do you have an array of objects of the structure type? — Vlad from Moscow, Feb 26 '23 at 21:10

score 0 · Answer 1 · answered Feb 26 '23 at 21:23

char **copyStr(const word *src, size_t nElements)
{
    char **result = NULL;
    if(src && nElements)
    {
        result = malloc(nElements * sizeof(*result));
        if(result)
        {
            for(size_t index = 0; index < nElements; index++)
            {
                size_t len = strlen(src[index].word);
                result[index] = malloc(len + 1);
                if(result[index])
                {
                    memcpy(result[index], src[index].word, len + 1);
                }
                else {/* handle error */}
            }
        }
    }
    return result;
}

Copying a subarray from an array of substrings in c

1 Answers1