学步园

场景:

1.有时候需要把十六进制的颜色值转换为整型值。

2.有时候需要生成二进制格式的特定文件。

#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;
}

生成的二进制文件: