Thread: Need EOF help trying to extract data from .dat file

Hello all,

I am trying to extract weather data from a (.dat) file. The contents of this space delimited file look like this:

2534 80 12 22 105 134 0
2971 74 9 20 106 163 0
2971 62 1 11 112 102 0
...
...

My problem is that I don't know the code to loop to the EOF in my while loop. I know it exists just not how to do it in this case.

Here is my code:

Code:

#include <stdio.h>

#define arrSize 33

int main()
{
	/* variable declarations */
	int stationNumberInput;

	int loop1;

	int	stNum,
		year,
		month,
		day,
		hiTemp,
		lowTemp,
		rain;

	int tempArray[arrSize] = {0};
	int daysArray[arrSize] = {0};
  
	double avg;
  
	FILE *in;

	/* prompt for inuput */
	printf("Please enter station number: ");
	scanf("%d", &stationNumberInput);

	/* attempt to open the file */
	in = fopen("weather.dat", "r");
	if(in == NULL)
	{
	    printf("Error opening file. Program terminated.\n");
	    return(1);
	}

	/* scan the file, store the temp, keep track of number of days */

	while( ??? )
	{		
		fscanf(in, "%d %d %d %d %d %d %d", &stNum, &year, &month, &day, &hiTemp, &lowTemp, &rain);

		if(stNum == stationNumberInput)
		{
			tempArray[year-48] += (hiTemp - 100);
			daysArray[year-48] += 1;
		}
	}

	/* print results */
	printf("\tYear\tRainfall\n");
	printf("\t----\t--------\n");
		
	for(loop1=0; loop1<arrSize; ++loop1)
	{
	    avg = tempArray[loop1] / (double)daysArray[loop1];
	    printf("\t%d\t%f\n", loop1+48, avg);
	}

	fclose (in);

	return 0;
}

Thanks in advance.

Hammer told you the answer!

You could always try

Code:

while(fscanf(in, "%d %d %d %d %d %d %d", &stNum, &year, &month, &day, &hiTemp, &lowTemp, &rain) != EOF)
{


}

Mr. C.

i might be repeating hammer, but it's important to realize that EOF is an integer, not a byte. therefore, it's returned by the operating system when it detects that user program x is trying to access space outside the size of the file. while fscanf avoids ambiguity, using functions like feof() can cause confusion among newbies, who use a char to accept the data returned, and wonder why they aren't getting an EOF.