[C/C++]_[十六进制字符串转换数值并写入文件]

#include <stdio.h>
#include <stdint.h>
#include <assert.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

size_t ConvertHexStrToInt(const char* hex_str,size_t length)
{
size_t sum = 0;
for(size_t i = 0;i < length; ++i)
{
int asc = (int)hex_str[i];
size_t r1 =(asc & 0x40)?(asc&0x0F)+0x9:(asc & 0x0F);
sum+=(r1*pow(16,length-i-1));
}
return sum;
}

uint8_t * ConvertToBinBuf(const char* hex_str,size_t *buf_size)
{
if(!hex_str)
{
*buf_size = 0;
return NULL;
}
//1.偶数个
size_t len = strlen(hex_str);
assert(!(len%2));

*buf_size = len/2;
uint8_t* buf = (uint8_t*)malloc(*buf_size);

for(size_t i = 0,j = 0; i<len; i+=2,++j)
{
uint8_t value = (uint8_t)ConvertHexStrToInt(hex_str+i,2);
buf[j] = value;
}
return buf;
}

int main(int argc, char *argv[])
{
printf(".......................\n");

const char* str= "000000DD000000E00000015C000000E2";
//	uint8_t buf[]=
//	{
//		0x00,0x00,0x00,0xDD,
//		0x00,0x00,0x00,0xE0,
//		0x00,0x00,0x01,0x5C,
//		0x00,0x00,0x00,0xE2
//	};

FILE* file = fopen("E:/1.bin","wb");
assert(file);

size_t len = 0;
uint8_t* buf2 = ConvertToBinBuf(str,&len);
fwrite(buf2,1,len,file);
free(buf2);

fclose(file);

printf(".......................\n");
return 0;
}