写面这段程序是用来删除c语言中的注释语句，有处理带引号的字符窜和字符常量的功能，小弟有点看不明白，是怎么删除注释，请指教！



/* 标准文档模板 */

#include "Stdio.h"
#include "Conio.h"

void rcomment(int c);
void in_comment(void);
void echo_quote(int c);

  main(void)
{
 int c,d;
  while ((c = getch()) != EOF)
  rcomment(c);       /* 此处添加你自己的代码 */
  getch();
  return 0;
}

  void rcomment(int c)
   {
     int d;

      if (c == '/')
         if ((d = getchar()) == '*')
             in_comment();
         else if (d == '/')
        {
             putchar(c);
             rcomment(d);
         }
         else {
         putchar(c);
         putchar(d);
         }
      else if(c == '\'' || c == '"')
      echo_quote(c);
      else
       putchar(c);
      }

 void in_comment(void)
    {
      int c,d;

      c = getchar();
      d = getchar();
      while (c != '*'|| d != '/')
      {
         c = d;
         d =getchar();
         }

       }

 void echo_quote(int c)
   {
     int d;

     putchar(c);
     while ((d = getchar()) != c)
       {
         putchar(d);
        if (d == '\\')
        putchar(getchar());
    }
  putchar(d);
 }