operating system - getting ambigious keypress event in c++ -

i have written simple program detect key press event. up, down, left, right , esc key returning 27!! can not differentiate, key has pressed.

#include<iostream> #include<stdio.h> #include<termios.h> using namespace std;  static struct termios oldsettings,newsettings;  void inittermios(bool echo) {         tcgetattr(0,&oldsettings);         newsettings=oldsettings;         newsettings.c_lflag &=~icanon;         newsettings.c_lflag &= echo ? echo : ~echo;         tcsetattr(0,tcsanow,&newsettings); }  void resettermios(void) {         tcsetattr(0,tcsanow,&oldsettings); }  char getch(bool echo) {         inittermios(echo);         char c=getchar();         resettermios();         return c;  }  int main() {         int i=getch(false);         cout<<i<<endl;         return 0;  } 

what suppose remove ambiguity ??