#### In C ##### Create a function that reads a text file with single digit value

Question

#### In C #####

Create a function that reads a text file with single digit values seperated by commas. The return value should be -1 if the EOF was reached before the array was filled, -2 if the EOF was not reached before the array was filled, -3 if opening the file failed, or 0 otherwise. Values should point to a pre-allocated array with a length of numValues. At the completion of this function, values should contain the values from the original text file.

Conversion from the read character to an integer value can be done with the
following function:

int char_to_int(char c) {return c - '0';}

the function should be of the form:

int read(char* fileLocation, int numValues, int* values);

Explanation / Answer

#include<stdio.h>
int char_to_int(char c) {return c - '0';}

// function definition
int read(char* fileLocation, int numValues, int* values)
{
   int i=0; // iterator for array
   int array_full_eof_not_reached=0; // flag to mark that array full before eof
   char ch; // variable for character input
   FILE *fin = fopen(fileLocation,"r");
   if(fin == NULL) return -3;
  
   while(fscanf(fin,"%c,",&ch) != EOF)
   {
       printf("%c %d ",ch,i);
       if(i<numValues)
values[i++]= char_to_int(ch);
       else
       {
           array_full_eof_not_reached = 1;
           break;
       }
      
   }
   //printf("%d ",i);
  
   if(i<numValues) return -1;
   if(array_full_eof_not_reached == 1) return -2;
   return 0;
   
}

// funtion ends

int main()
{
   int arr[10];
   printf("%d ",read("in.txt",5,arr));
   return 0;
  
}

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