File i/o help!

[omGeeK]

So my professor gave us a sample program below, and it does not work, the program i must write must have an input of pi (1million numbers of precision) but i have no clue on how to start seeing as how the sample program doesnt even work lol. I understand how to do everything, besides setting up my file input correctly which apparently my professor cant do... Any help would be gracious.

Edit: Everytime i run the sample it says my "error opening myinput.txt" which means that infile==null, but i dont know what that means, is my input file wrong or can it just not read because of something else.

Edit 2: Okay now i am not getting the error, but nothing is printing in the output...??? thoughts

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>

void main()
{
	FILE *infile;
	FILE *outfile;
	int x,y,z,sum;
	float avg;

	// Open input file, exit if error
	infile=fopen("myinput.txt","r+t");
	if (infile==NULL) 
	{ 
		printf("Error opening myinput.txt\n"); 
		exit(0); 
	}
	
	// Generally file opens are done as below
	if ((outfile=fopen("myoutput.txt","w+t"))==NULL) 
	{ 
		printf("Error opening myoutput.txt\n"); 
		exit(0); 
		
	// read the three values 
	// its a good idea to  account for \n's in the file
	fscanf(infile,"%d\n",&x);
	fscanf(infile,"%d\n",&y);
	fscanf(infile,"%d\n",&z);

	// sum and avg
	sum = x+y+z;
	avg = (float)sum/3.0;

	// print out values
	fprintf(outfile,"Values: %d, %d, %d\n",x,y,z);
	fprintf(outfile,"Sum: %d\n",sum);
	fprintf(outfile,"Avg: %7.2f\n",avg);

	// close the files
	fclose(infile);
	fclose(outfile);
	}
}

[claudiu]

Is the file in the same directory as the executable?

Do you have permissions to read the file?

Also, void main should be int main(void) and should return 0.

[omGeeK]

view next post

[omGeeK]

well i changed this

	// Generally file opens are done as below
	if ((outfile=fopen("myoutput.txt","w+t"))==NULL) 
	{ 
		printf("Error opening myoutput.txt\n"); 
		exit(0); 
		
	// read the three values 
	// its a good idea to  account for \n's in the file
	fscanf(infile,"%d\n",&x);
	fscanf(infile,"%d\n",&y);
	fscanf(infile,"%d\n",&z);

	// sum and avg
	sum = x+y+z;
	avg = (float)sum/3.0;

	// print out values
	fprintf(outfile,"Values: %d, %d, %d\n",x,y,z);
	fprintf(outfile,"Sum: %d\n",sum);
	fprintf(outfile,"Avg: %7.2f\n",avg);

	// close the files
	fclose(infile);
	fclose(outfile);
	}
}

to this and it works fine now...

	// Generally file opens are done as below
	if ((outfile=fopen("myoutput.txt","w+t"))==NULL) 
	{ 
		printf("Error opening myoutput.txt\n"); 
		exit(0); 
	}	
	// read the three values 
	// its a good idea to  account for \n's in the file
	fscanf(infile,"%d\n",&x);
	fscanf(infile,"%d\n",&y);
	fscanf(infile,"%d\n",&z);

	// sum and avg
	sum = x+y+z;
	avg = (float)sum/3.0;

	// print out values
	fprintf(outfile,"Values: %d, %d, %d\n",x,y,z);
	fprintf(outfile,"Sum: %d\n",sum);
	fprintf(outfile,"Avg: %7.2f\n",avg);

	// close the files
	fclose(infile);
	fclose(outfile);
	
}