关于UCOS操作系统很实用的资料,讲了许多经典的问题

				////////////////////////////////////////////////////////////////////////////////////////////
				//
				//    
				//    File: printf.c
				//
				//    Copyright (C): 2005 Searen Network Software Ltd.
				//
				//    [ This source code is the sole property of Searen Network Software Ltd.  ]
				//    [ All rights reserved.  No part of this source code may be reproduced in ]
				//    [ any form or by any electronic or mechanical means, including informa-  ]
				//    [ tion storage and retrieval system, without the prior written permission]
				//    [ of Searen Network Software Ltd.                                        ]
				//    [                                                                        ]
				//    [   For use by authorized Searen Network Software Ltd. employees only.   ]
				//
				//    Description:   This class can read, write and watch one serial port.
				//					 It sends messages to its owner when something happends on the port
				//					 The class creates a thread for reading and writing so the main
				//					 program is not blocked.
				// 
				//
				//
				//  AUTHOR: Ren Yu.
				//  DATE: Sept. 12, 2005
				//
				//
				/////////////////////////////////////////////////////////////////////////////////////////////
				//
				#include "printf.h"
				#include "windows.h"
				#include "includes.h"
				#include 
				
				/////////////////////////////////////////////////////////////////////////////////////
				//
				//
				void  put_char ( char ch )
				{
					PWINDOWS ptr = GetActiveWindow();
				
					if (ch == '\n' || ch == '\0')
					{
						if (ptr->cy < (ptr->ey - ptr->sy))
						{
							if (ptr->cy < ptr->ey - 1)
								ptr->cy ++;
						}
						else
						{
							if (ptr->cy < ptr->ey - 1)
								ptr->cy ++;
						}
						ptr->cx = 0;
					}
					else
					{
						PC_DispChar(ptr->cx, ptr->cy, ch, ptr->color);
						ptr->cx ++;
					}
				}
				
				void  printshort ( int n, const char* fmt )
				{
					char buf[50], c;
					int i = 0;
				
					sprintf( buf, fmt, n);
					while (i < 50)
					{
						c = buf[i];
						if (c == '\0')
							return;
						put_char(c);
						i ++;
					}
				
				}
				
				void  printfloat ( float n, const char* fmt )
				{
					char buf[50], c;
					int i = 0;
				
					sprintf( buf, fmt, n);
					while (i < 50)
					{
						c = buf[i];
						if (c == '\0')
							return;
						put_char(c);
						i ++;
					}
				}
				
				void  print ( const char * fmt, ... )
				{
					register char *s, *n, *p, par[8];
					register *adx, c, cn;
				
					adx = &fmt + 1;			//point to first param
				loop:
					while ((c = *fmt ++) != '%' )
					{
						put_char(c);
						if (c == '\0')
							return;
					}
					c = *fmt ++;
					if (c == 'd')
					{
						printshort(*(int*)adx, "%d");
						adx += 1;
					}
					else if (c == 'f')
					{
						printfloat(*(double*)adx, "%f");
						adx += 4;
					}
					else if (c == 's')
					{
						s = *(char**)adx;
						while (c = *s++)
						{
							if (c == '\0')
								break;
							put_char(c);
						}
						adx += 2;
					}
					else if( c >= 48 && c < 58 || c == '.' )	//格式输出 %3.2f %3f %.3f %3.f
					{
						n = fmt - 2;
						memcpy(par, n, 8);
				
						if ((p = strstr(par, "d")) != NULL)
						{
							*(p+1) = '\0';
							printshort(*(int*)adx, par);
							fmt += p - par - 1;
							adx += 1;
						}
				
						if ((p = strstr(par, "f")) != NULL )
						{
							*(p + 1) = '\0';
							printfloat( *(double*)adx, par );
							fmt += p - par - 1;
							adx += 4;
						}
					}
					else
					{
						put_char('%');
						fmt--;
					}
				
					goto loop;
				}
				
				//////////////////////////////////////////////////////////////////////////////////////