Implementation of conio.h under Linux

Reference:
http://kpld.spaces.live.com/Blog/cns!8AC759DD08B8D806!181.entry
http://sourceforge.net/projects/linux-conioh/files/

// 在linux下需要修改terminal的属性
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
 
#undef TERMIOSECHO
#define TERMIOSFLUSH
 
/*
 * kbhit() -- a keyboard lookahead monitor
 *
 * returns the number of characters available to read
 */
static int kbhit ( void )
{
    struct timeval tv;
    struct termios old_termios, new_termios;
    int            error;
    int            count = 0;
    tcgetattr( 0, &old_termios );
    new_termios              = old_termios;
    /*
     * raw mode
     */
    new_termios.c_lflag     &= ~ICANON;
    /*
     * disable echoing the char as it is typed
     */
    new_termios.c_lflag     &= ~ECHO;
    /*
     * minimum chars to wait for
     */
    new_termios.c_cc[VMIN]   = 1;
    /*
     * minimum wait time, 1 * 0.10s
     */
    new_termios.c_cc[VTIME]  = 1;
    error                    = tcsetattr( 0, TCSANOW, &new_termios );
    tv.tv_sec                = 0;
    tv.tv_usec               = 100;
    /*
     * insert a minimal delay
     */
    select( 1, NULL, NULL, NULL, &tv );
    error                   += ioctl( 0, FIONREAD, &count );
    error                   += tcsetattr( 0, TCSANOW, &old_termios );
    return( error == 0 ? count : -1 );
}  /* end of kbhit */
/*------------------------------------------------*/
int getch( void )
{
      int c = 0;
      struct termios org_opts, new_opts;
      int res = 0;
          //-----  store old settings -----------
      res = tcgetattr( STDIN_FILENO, &org_opts );
      assert( res == 0 );
          //---- set new terminal parms --------
      memcpy( &new_opts, &org_opts, sizeof(new_opts) );
      new_opts.c_lflag &= ~( ICANON | ECHO | ECHOE | ECHOK | ECHONL | ECHOPRT | ECHOKE | ICRNL );
      tcsetattr( STDIN_FILENO, TCSANOW, &new_opts );
      c = getchar();
          //------  restore old settings ---------
      res = tcsetattr( STDIN_FILENO, TCSANOW, &org_opts );
      assert( res == 0 );
      return( c );
}