Re: gcc err : undefined reference to ?

still confuse :
completed code here : cygwin enviroment

// test.cpp
// use -lstdc++

#include <stdio.h>
#include <unistd.h>
#include <iostream>

#include "LinuxTerminal.h"

using namespace std;

//this printch function is just for test ,direct use this can pass the test
print
/* void printch(char* ch){
  fprintf(stdout,"%c",*ch);
}
*/

int main(int argc, char *argv[])
{
  char* q = new char();

  *q = 'c';

   printf("print a new line of doing test");

   LinuxTestTerminal* lt = new LinuxTestTerminal();
   lt->printch(q);

   //printch(q); // direct use this can pass,but lt->printch(q) can not
,why?

   while(true); // test perpose loop

}

***********************************
// Terminal.h

#ifndef __TERMINAL_H_
#define __TERMINAL_H_

class Terminal{ // this is virtual class of terminal
 public:

  /* <--- comment for test perpose
  virtual void printch(char*) = 0;
  virtual void backSpace() = 0;
  virtual void printCR() = 0;
  virtual void printTab() = 0;
  */

};

#endif // __TERMINAL_H_

***********************************
// LinuxTerminal.h

#ifndef __LINUXTERMINAL_H_
#define __LINUXTERMINAL_H_

#include "Terminal.h"

class LinuxTestTerminal : public Terminal{
public:

  void printch(char* ch );
  // void printch(char ch);
  void backSpace();
  void printCR();
  void printTab();

};

#endif // __LINUXTERMINAL_H_

****************************************
// LinuxTerminal.cpp
void
LinuxTestTerminal::printch(char* ch){
  fprintf(stdout,"%c",*ch);
}

void
LinuxTestTerminal::backSpace(){
   fprintf(stdout,"\b")
}

void
LinuxTestTerminal::printCR(){
  fprintf(stdout,"/n");
}

void
LinuxTestTerminal::printTab(){
  fprintf(stdout,"/t");
}