自己写printf函数

 1 void PrintInt(int i)
 2 {
 3     int sign = i>0 ? 0 : 1;
 4     u8 s[10];
 5     int cnt=0;
 6     if(sign)
 7     {
 8         StatlWrite((u8 *)‘-‘,1);
 9         i = -i;
10     }
11     int ten = i%10;
12     while(i)
13     {
14         s[cnt] = ten+‘0‘;
15         cnt++;
16         i /= 10;
17         ten = i%10;
18     }
19     while(cnt>0)
20     {
21         StatlWrite(&s[--cnt],1);
22     }
23 }
24 
25 void PrintStr(char* str)
26 {
27     while(*str != ‘ ‘)
28     StatlWrite((u8 *)str++,1);
29 }
30 
31 void PrintChar(u8 *c)
32 {
33     StatlWrite((u8 *)c,1);
34 }
35 
36  
37 
38 int myprintf (char *format, ...)
39 {
40     va_list arg;
41     static char stepflag =0;
42     int Decdate;
43     char Hex;
44     char* String;
45 
46     va_start (arg, format);
47     do
48     {
49         if(*format != ‘%‘)
50         {
51             if(stepflag==1)
52             {
53                 stepflag = 0;
54                 format++;    
55             }
56             else
57             {
58                 PrintChar((u8*)format++);
59             }
60         }
61         else
62         {
63             stepflag = 1;
64             switch(*(++format))
65             {
66                 case(‘d‘):
67                     Decdate = va_arg(arg,int);
68                     PrintInt(Decdate);
69                 break;    
70                 case(‘c‘):
71                     Hex = va_arg(arg,int);
72                     //PrintChar(Hex);
73                 break;
74                 case(‘s‘):
75                     String = va_arg(arg,char *);
76                     //PrintStr(String);
77                 break;
78                 default:
79                 //myprintf("I need relax.");
80                 break;
81             }    
82         }
83     }
84     while(*format != ‘\0‘);    
85 
86     va_end (arg);
87     return 1;
88 }