#include <stdlib.h>
#include <ctype.h>	
#include "tdp.h"	
	
xdata char cmdbuf [1 + MAX_CMD_LEN];	
xdata unsigned char cmdndx;	
	
/* 初始化 */
void cmdb_init (void) {	
	cmdndx = 0;	
	cmdbuf [0] = '\0';	
}	
	
/* 命令提示"COMMAND" */
void cmdb_prompt (void) {	
	com_puts ("COMMAND: ");	
	com_puts (cmdbuf);	
}	
	
/* 輸入命令掃描 */
const char *cmdb_scan (void) {	
	int c;	
while (1)  {	
  if ((c = com_getchar ()) == -1)	
    break;	
  if (c == '\r')	 {	
    com_puts ("\r\n");	
    return (cmdbuf);	
  }	
  if ((c == '\b') && (cmdndx != 0))	{	
    com_puts ("\b \b");	
    cmdbuf [--cmdndx] = '\0';	
    continue;	
  }	
  if (!isprint (c))	{	
BEEPCHAR: com_putchar ('\x7');	
    continue;	
  }	
  if (cmdndx >= MAX_CMD_LEN)	
    goto BEEPCHAR;	
  com_putchar (c);	
  cmdbuf [cmdndx++] = (unsigned char) c;	
  cmdbuf [cmdndx]   = '\0';	
}		
return (NULL);
}