workinWithtxt

#include<stdio.h>

int main(){
  char x,y;
  printf("Unesite znakove x i y: ");
  scanf(" %c %c",&x,&y);
  if(x>y){
    printf("Pogresan unos");
    return 1;
  }
  FILE* ulaz=fopen("input.txt","r");
  if(ulaz==NULL){
    printf("Datoteka ne postoji");
    return 1;
  }
  FILE* izlaz=fopen("output.txt","w");

  int c;

  while((c=fgetc(ulaz))!=EOF){
    for(;c!=EOF && c>=x && c<=y;c=fgetc(ulaz))
      fputc(c,izlaz);
  }
  fclose(ulaz);
  fclose(izlaz);
  return 0;
}