Why is data not being read on input from a file?

Question

C++ / C#

A simple example of a program taken from the book "Programming in C" by D. Griffiths. Takes two world coordinates (float) and an explanation for them (char []) from the input stream and formats this to the output stream in json format. When streaming from the keyboard, everything works fine. When reassigning: csv2json.exe < gps.txt > gps.json (as indicated in the book), the program writes that there are few parameters and their number = 0, i.e. actually refuses to read from a file. Such picture both in windows, and in Linux. Where did the dog dig?

#include <stdio.h>
#include<locale.h>

int main()
{
  
char *locale = setlocale(LC_ALL, "");

float latitude; 
float longitude; 
char info[80]; 
int started = 0;
int result;

printf("data=[");

while (1)	
{
  if ((result = scanf("%f,%f,%79[^\n]", &latitude, &longitude, info)) < 3)
  {
    printf("Слишком мало параметров %d", result);
    return 2;
  }
  else if(result >3)
  {
    printf("Слишком много параметров %d", result);
    return 2;
  }
  printf("The number of fields input is %d\n", result);
  if (started) 
    printf(",\n"); 
  else
  started = 1;
  if ((latitude < -90.0) || (latitude > 90.0)) {
    fprintf(stderr,"Неправильная широта: %f\n", latitude);
    return 2;
  }
  if ((longitude < -180.0) || (longitude > 180.0))	{
    fprintf(stderr, "Неправильная долгота: %f\n", longitude);
    return 2;
  }
  printf ("{latitude: %f, longitude: %f, info: '%s'}\n", latitude, longitude, info);
}

printf("]\n"); 



return 0;
}

File with coordinates:

42.363400,-71.098465,Speed=21  
42.363327,-71.097588,Speed=23
42.363255,-71.096710,Speed=17
42.363182,-71.095833,Speed=22
42.363110,-71.094955,Speed=14
42.363037,-71.094078,Speed=16
42.362965,-71.093201,Speed=18
42.362892,-71.092323,Speed=22
42.362820,-71.091446,Speed=17
42.362747,-71.090569,Speed=23
42.362675,-71.089691,Speed=14
42.362602,-71.088814,Speed=19
42.362530,-71.087936,Speed=16
42.362457,-71.087059,Speed=16
42.362385,-71.086182,Speed=21

Answer 1

Most likely an error in the files. They are called differently than you pass in the parameters, or they are in a different directory, or they are empty. And you see the correct text in another file. Check all the titles again. Or the first line is empty.