C Programming File I/O -

i'm trying read text file , write one, every time execute code, nothing happens text files. "nothing happens", mean program won't read input file , no data exported output file. point out why not working? given in advance. here code:

#include <stdio.h> #include <stdlib.h>  file *inptr, *outptr;   int main() {     int a, b, c;     inptr = fopen("trianglein.txt","r"); //initialization of pointer , opening of file trianglein.txt     outptr = fopen("triangleout.txt","w"); //initialization of pointer , opening of file triangleout.txt      while((fscanf(inptr,"%d %d %d",&a, &b, &c))!= eof){           fprintf(outptr,"\n%2d %2d %2d\n",a,b,c);          if(a+b>c && b+c>a && c+a>b){             fprintf(outptr, "this triangle.\n");              if(a !=b && b !=c && a!=c){                  fprintf(outptr, "this scalene triangle.\n");                 if(a==b && a==c && c==b){                     fprintf(outptr, "this equilateral triangle.\n");                     if(a*a+b*b==c*c || b*b+c*c==a*a || a*a+c*c==b*b){                         fprintf(outptr, "this right trianlge.\n");                     }                 }             }          }     }      return 0; } 

trianglein.txt contents:

10 12 15 2 3 7 3 4 5 6 9 5 6 6 6 6 8 10 7 7 9 

multiple problems.

firstly, need check if inptr , outptr valid testing against null.

secondly, fscanf can return either eof, 0 or > 0.

if input file doesn't contain valid input.

also there problems in can 3 ints read successfull, or 2 ints or 1 , value of a, b , c optionally set.

if no conversion took place on input value of 0 returned in case while loop exit.

also bear in mind scanf style functions input succeed , return value of 1.

"1rubbish"

i think may want following:

// somewhere near top #include <stderr.h> // ... other includes  const char* inname = "trianglein.txt"; const char* outname = "triangleout.txt";  // other stuff   // inside main...  // initialization of pointer , opening of file trianglein.txt if ((inptr = fopen(inname,"r")) == 0){   fprintf(stderr, "error opening file %s: %s", inname, strerror(inname));   return -1; }  // initialization of pointer , opening of file triangleout.txt if ((outptr = fopen(outname,"w")) == 0){   fprintf(stderr, "error opening file %s: %s", outname, strerror(outname));   return -1; }   int result; while(true){   result = fscanf(inptr,"%d %d %d",&a, &b, &c);   if (result == eof)     break;    if (result < 3)  // ignore incomplete lines     continue;    // normal stuff }