Why might my parse return seg.fault to check50?

Question

Below is my parse function in server.c pset6; The code is not fully commented yet, my bad; Nonetheless, why are all exit code 0 in check50, where is the loophole? Thank you.

bool parse(const char* line, char* abs_path, char* query)
{
    // TODO

    char * version = " HTTP/1.1";
    char * method = NULL;
    char * target = NULL;
    char x = '?', y = '/', z = '"';

    int n = strlen(query);
    int p = strlen(target);
    int a = strlen(line);
    int b = strlen(method);
    int c = strlen(version);
    int d = (a - b);
    int e = (d - c);
    int q = (p - n);

    if(line != NULL)
    {
        if(strchr(line, z) == 0)
        {
            error(400);
        }

        strncpy(method, line, 3);
        method[3] = '\0';

        if(strstr(method, "GET") != 0)
        {
            error(405);
        }
        else if(strstr(method, "GET") == 0)
        {
            for(int i = 0; i <= e; i++)
            {
            strncpy(target, line+4, d);
            }

            while(target != NULL)
            {

                if(strchr(target, z) == 0)
                {
                   error(400);
                }

                if(target[1] != y)
                {
                    error(501);
                }
                if(strstr(target, version) != 0)
                {
                   error(505); 
                }

                query = strchr(target, x);
                strncpy(abs_path, target, q);

                if(strchr(abs_path, '.') != 0)
                {
                    error(501);
                }

            }
        }

    }
    error(501);
    return false;
}

Answer 1

I have to tell you, with some regret, that you are a little far from the correct solution, look at the following statement:

char * method = NULL;
char * target = NULL;

Something later in your program you do:

int p = strlen(target);

To the function strlen we pass a pointer, but in your case the pointer is null, hence Segmentation fault. If you want you can see my answer in the link:

cs50.stackexchange.com/questions/22217/pset6-parse-help-what-does-it-want-me-to-do/22221#22221