Hello, I have written a small C programm where I can read data in from a .csv file. This works fine.

But now I want to create a function to read the data in. So I want modify my programm.

I have tried to put the fopen() in a function and to return this value. But this not works.

Here is my original program:

Code:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>



int main(void)
{

    FILE *fp;

    fp = fopen("data.csv","r");

    if (fp == NULL)
    {
        printf("Can not open file");
        exit(0);
    }

    char line[100];
    char *sp;
    double acceleration;
    double rotation;
    double temperature;
    double totalTemperature;
    int count = 0;


    double direction=0;

    while(fgets(line, 100, fp )!= NULL)
    {
        sp = strtok(line, ",");
        acceleration = atof(sp);

        sp = strtok(NULL, ",");
        rotation = atof(sp);

        sp = strtok(NULL, ",");
        temperature = atof(sp);

        totalTemperature += temperature;
        count++;


    }

    printf("The mean Temperature is: %.14f\n", totalTemperature/count);

    fclose(fp);

    return 0;

}

As I said I want to create a function named read_data(), i want to modify my orignal program. This function should read the data from the .csv file, but I did not know what the return should be look like.

I have tried something like that, but it did not worked:

Code:
char * read_data(char* filename)
{

    FILE *fp;

    fp = fopen("data.csv","r");

    if (fp == NULL)
    {
        printf("Can not open file");
        exit(0);
    }

    fclose(fp);

    return fp;


}
Thanks for a help.