int myatoi(const char *str) //将字符str转换为整数
{
const char *p = NULL;
int neg; //标志位，0代表负数，1代表正数
if (str[0] == '-') //str为负整数，置neg标志位为0
{
neg = 0;
p = ++str; //将字符串str字符串中的'-'去除，从str的第二位开始转化
}
else //否则置neg标志位为1
{
neg = 1;
p = str;
}
int i_len = len(p); //调到字符串长度
int i_temp = i_len;
int value = 0;
int i = 0;
for (; i < i_len; i++) //从str[0]开始遍历字符串
{
value += (power10(i_temp - 1) * char2i(p[i]));
i_temp--;
}
if (neg == 0) //str为负数 ，将转化后的字符串前
{
return 0 - value;
}
else
{
return value;
}
}
/*----------------------------------------------------------string2int()
Purpose: convert string (hex eg:ab or int eg: 234) to int
Parameters:
Input: - c:pointer to char: least significant digit of number
- length: number of digits
- base b = h : string represents hexa number
d : string represents decimal number
Output: w32 *num
Return: 1 if error
0 if ok
Output: *num - converted number
*/
int string2int(char *cstr,w32 length,w32 *num,char b){
int i;
w32 digit,base,power;
//printf("string2int: cstr%s len:%d base:%c\n", cstr, length, b);
if(length <=0){
printf("string2int error: string length=%i <=0 \n",length);
return 1;
}
if(cstr == NULL){
printf("string2int error: cstr=NULL \n");
return 1;
}
//printf("string2int start:%s strlength=%i \n",cstr,length);
if(b == 'h') base=16 ;
else if( b == 'd') base =10;
else{
printf("string2int error: unknown base %cstr \n",b);
return 1;
}
if(length>(2*sizeof(w32)) && b =='h'){
printf("string2int error: length=%i >2*sizeof(w32) \n",length);
return 1;
}
if(length>9 && b == 'd'){
printf("string2int error: length=%i >2*sizeof(w32) \n",length);
return 1;
}
*num=0; i=0; power=1; cstr= cstr + length-1;
while(i<(int)length){
//printf("ss= %c \n",*cstr);
if(char2i(*cstr,&digit) == 0) *num=*num+digit*power; else return 1;
power=power*base;
cstr--;
i++;
if(*cstr==' ') break; // ignore leading spaces
};
//if((b =='h'))printf("num= 0x%x \n",*num);else printf("num= %i \n",*num);
return 0;
}
