Question

I’m relatively new to C in general and I’m having a problem with some code. It’s pretty simple code: The objective of the code is to copy a given array of char pointers, or char **source, in other words, to a given char **destination.

The issue I’m having is that sometimes (usually when I have more than 2 strings in source) the first element gets completely corrupted and when I end up printing out destination, it will print out something like “;@?” for the first element, with the other elements printing fine.

The code that performs the copying is:

void CopyArrayOfStrings(char **source, int numStrings)
{
   char **destination = malloc(numStrings);

    for (int i = 0; i < numStrings; i++)
    {
        destination[i] = malloc(strlen(source[i] + 1);
        strcpy(destination[i], source[i]);
    }
}

Note that I left out the code that checks if the result of malloc is NULL.

Answer 1

You need to change your allocation of destination as :

char **destination = malloc(numStrings*(sizeof(char*)));

to allocate number of char * pointers to hold strings.

Also verify you are appropriately passing char ** as source array of strings.