Finding unique strings within a file

[oceans]

Hello all,

I have been trying to write this program that reads a file of courses and then stores only the unique courses in an array of strings.

for some reason it crashes while reading the 2nd line.

printf within the function are just for me trying to trace the problem.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char** uniqueCourses(FILE *fp, int *wordCount);


int main()
{
    FILE* fp;
    char** in;
    int i =0;
    int n =0;
    int* w = &n;
    fp = fopen("data.txt","r");
    in = uniqueCourses(fp,w);


    for (i=0; i <3; i++)
    {
        printf("%s",in[i]);
    }
    return 0;
}
char** uniqueCourses(FILE *fp, int *wordCount)
{
    char* del = ",";
    char* token;
    char buffer[100];
    char** myArray;
    myArray = malloc(50* sizeof(char*));
    int i = 0;
    int v=0;
    int flag =0;
    int count = 0;


    while(fgets(buffer,sizeof(buffer),fp) != NULL)
    {


        token = strtok(buffer,del);
        while(token != NULL)
        {
            if (count == 0)
            {
                myArray[i] = malloc(10 * sizeof(char));
                strcpy(myArray[i],token);
            }




            for (v =0; v<count; v++)
            {
                if (strcmp(myArray[v],token) == 0)
                {
                    flag = 1;
                    break;
                }
            }
            printf("2");


            /* if not then store it in our main array */
            if (flag != 1 )
            {
                i++;
                myArray[i]= malloc(10 * sizeof(char));
                strcpy(myArray[i],token);
                printf("%s",myArray[i]);


            }
            printf("3");
            count++;
            token = strtok(NULL,del);


        }
        printf("1");


    }


    return myArray;


}

[laserlight]

What is the file format?

It looks like you are doing too much in a single function.

Write a function that reads the information for a single course from the file. Test that this function works correctly.

Write another function that uses the previous function to read all courses from the file. Test that this function works correctly.

Amend the previous function to check for duplicates before adding to course to the array. Or, write another function to remove duplicates.

[oceans]

file format is basically comma delimited course names and multiple functions will definitely make it easier but i'm required to do it all in one function.

[laserlight]

file format is basically comma delimited course names and multiple functions will definitely make it easier but i'm required to do it all in one function.

Since you are only reading course names, i.e., just single strings, you probably do not need a separate function that reads the information for a single course from the file. That said, I doubt that you are required to do it all in a single function, only that it is probably simple enough to do so. (Or if you really are required to do that, then it implies that your teacher is a bad programmer, or is trying to teach by negative example, but this simple scenario hardly qualifies as a negative example.)

So, if you want, you can combine the first two functions into one, and if you amend this function instead of writing a separate function to eliminate duplicates, you really would end up with just one function. But do this step by step.

[zub]

Program could be greatly simplified if you know the maximum length of the course.

Otherwise, I advise you to look at this source code - SourceForge.net Repository - [cutest] Contents of /cutest/CuTest.c

You will learn to make a very comfortable string operations. Your program become trivial with such framework.

[oceans]

Thank you everyone! I was able to fix my original code. I just had to to reset the flag counter, add "counter!=0" to if statement along with flag!= 0 and move counter++ and i++ within the conditionals.