Question

I am pretty confused with pointers in C. I am finding it hard to wrap my mind around creating them and passing stuff around? I have a “Segmentation Fault: 11” error after I added code, in which previously it worked. Needed to add something. This is part of the code:

char *token2;
char *line2;
char comma_loc = 0;
int num_of_commas = 0;
char *line2[1];

while(token != NULL) { //lets make sure token has a string token
        //printf("Wats in token: %s\n", token);
        if(key==true) {
            //printf("This should be an identifier: %s\n", token);

            if(comma != true) { //added if statement, just take away if it fails, the first case is the original
            int len = strlen(token);
            iden_holder[iden_holder_count] = (char *)malloc(sizeof(char) * (len +1));
            memcpy(iden_holder[iden_holder_count], token, len +1);
            iden_holder_count++;
            key = false;
            } else {

                int len2 = strlen(token);
                line2[0] = (char *)malloc(sizeof(char) * (len2 + 1));
                memcpy(line2[0], token, len2 + 1);
                token2 = strtok(line2[0],",");
                    while(token2 != NULL) {
                            int len = strlen(token2);
                            iden_holder[iden_holder_count] = (char *)malloc(sizeof(char) * (len +1));
                            memcpy(iden_holder[iden_holder_count], token, len +1);
                            iden_holder_count++;
                            token2 = strtok(line2[0],",");
                        }
                key = false;

            }

Point of this code is to take the string within token and copy it into another token, in my case token2. I decided to use memcpy, but I am confused how to use it due to the pointers confusion. I should also note that I used strtok before this, and the code here is within in. Could it be that if I use it again that it will override the other one?

Answer 1

Read this completely. It will help you with your basics. It did to me. 🙂