Read File Problem

I am trying to get a list of numbers from a file and store each number in an array.

I think I have the structure right but I'm getting a memory referance error and the warning that comes up is:

'l' : unrecognized character espace sequence

what does that mean?

here is my read_file function

Code:

---

// Read data file
double read_file(int num_temps, double temps[])
{
        int i=0;
        double temp;
        FILE *filedata;

        filedata = fopen(DATA,"r");
        if(filedata == NULL)
        {
                printf("Error opening file.\n");
        } else {
                while (fscanf(filedata,"%lf",&temp) == 2)
                {
                        temps[num_temps] = temp;
                        num_temps++;
                }
        }
        fclose(filedata);
        return num_temps;
}

---

Is DATA declared globally?

What is a "memory reference error", and which line of code exactly do you get that warning on?

num_temps is probably the number of elements in the array. So using that as an index into the array will produce buffer overflow. you need a different counter that starts with 0 and goes up to, but not including, num_temps as the array index. For example

Code:

---

temps[i++] = temp;

---

now change the loop to stop when i == num_temps as well as the existing condition.

Finally, I think fscanf() will return 1, not 2, which is the nuumber of items converted.

I made changes as suggested but still same error.

Ok I made some changes. However no data is pulled from the text file.

Code:

---

double read_file(int num_temps, double temps[])
{
        int i=0;
        double temp;
        FILE *filedata;
        filedata = fopen("c:\\labdata.txt","r");

        if(filedata == NULL)
        {
                printf("Error opening file.\n");

        } else {

                while (fscanf(filedata,"%lf",&temp) == 1)
                {
                        temps[i++] = temp;
                }
        }
        fclose(filedata);
        num_temps = i;

        return num_temps;
}

---

When would this ever be true...

Code:

---

while (fscanf(filedata,"%lf",&temp) == 2)

---

...scanning for one value and continuing only when you get two?

Ok, now it reads the first number in my file. But thats it...

So let's see your latest code.


Quzah.

Code:

---


}

// Read data file
double read_file(int num_temps, double temps[])
{
        int i=0;
        double temp;
        FILE *filedata;
        filedata = fopen("c:\\labdata.txt","r");

        if(filedata == NULL)
        {

                printf("Error opening file.\n");

        } else {

                while ((fscanf(filedata,"%lf ",&temp)) == 1)
                {
                        temps[i] = temp;
                        i++;
                }

        }

        fclose(filedata);

        num_temps = i;

        return num_temps;

}

---

what is the complete type of the thing passed as the second parameter to the function?

What error/warnings are you getting, and what line(s) do they refer to?

How do you know the problem is with that function?

hmmm I copied your code and made it into a main function so I could run it, and its working fine. I added some printf's so i could see if it was working correctly, and it seemed to be. here's the code I have:

Code:

---

#include <stdio.h>

int main()
{
        int i=0;
        double temp;
        FILE *filedata;
    int num_temps;
    double temps[100];
        filedata = fopen("c:\\labdata.txt","r");

        if(filedata == NULL)
        {

                printf("Error opening file.\n");

        } else {

                while ((fscanf(filedata,"%lf ",&temp)) == 1)
                {
                        temps[i] = temp;
            printf("%g\n", temps[i]);
                        i++;
                }

        }

        fclose(filedata);

        num_temps = i;

        printf("%d numbers in the file.\n", num_temps);

        return 0;
}

---

thanks. i got it working. just had to add a little pointer in there from my function :)