Question

 void readit(FILE* filePtr, int* num1, int* num2, char** strings, int lines)
     {
int t;
char line[50];

for (t = 0; t < lines; t++){
    fgets(line, 50, filePtr);
    *(strings + t) = strtok(line, " "));
    *(num2 + t) = atoi(strtok(NULL, " "));
    *(num2 + t) = atoi(strtok(NULL, " "));
}

In this code, the *strings portion is not performing as intended. Every pass through the code overwrites the entire string array. The fgets is reading in the correct data, and every loop through if I print the value of the first token, it is what I expect. Outside of the loop, (or inside if i print (i – 1) all the arrays *str + 1, *str + 2 etc.. Will contain the value of the last pass through.

For example.

         *(strings + 0) = "Hi";
         printf("%s", *(strings + 0)); //Will print hi

         //next iteration
         *(strings + 1) = "You";
         printf("%s", *(strings + 1)); // will print you
         printf("%s", *(strings + 0)); // will print you as well

Answer 1

The problem is that you only have one string buffer that is constantly being over-written. Remember strtok does not allocate new memory it returns a pointer into the buffer it is passed. Each time through the loop strtok sets *(strings + t) = line. Then in the next loop you over-write the date in line. What you are ending up with is an array of char pointers all pointing to the same string buffer. (You are also returning a pointer to a local variable, which is undefined behavior)

You code is equivalent to to the following:

    char *strings[2];
    char line[50];
    strcpy(line, "Hi");
    *(strings + 0) = line;
     printf("%s", *(strings + 0)); //Will print hi

     //next iteration
     strcpy(line, "You");
     *(strings + 1) = line;
     printf("%s", *(strings + 1)); // will print you
     printf("%s", *(strings + 0)); // will print you as well

So both strings+0 and string+1 point line so of course over-writing line with change what strings+0 prints.

You either need to allocate memory dynamically or base in a buffer that you can strcpy into. For example:

char strings[5][50];
readit(filtPtr, &num1, &num2, strings, 50);

...

void readit(FILE* filePtr, int* num1, int* num2, char** strings, int lines)
{
     int t;
     char line[50];

    for (t = 0; t < lines; t++){
        fgets(line, 50, filePtr);
        strcpy(*(strings + t), strtok(line, " ")));
        *(num2 + t) = atoi(strtok(NULL, " "));
        *(num2 + t) = atoi(strtok(NULL, " "));
    }
}