16floatpow.c

16进制浮点数换算

#include "stdio.h"
#include "conio.h"
#include "math.h"
htof();
ftoh();
testhex();
unsigned char AscToHex(unsigned char da);
pow_test();
void tst_pow (void);
main()
{
/* testhex();
 htof();*/
 ftoh();
 /*pow_test();*/

}
testhex()
{
    unsigned char unixtimetemp2[4];
    long int unixtimetemp=0,unixtimetemp1=0;
    float fvalue = 7295;
    unixtimetemp2[0] = 0x11;
    unixtimetemp2[1] = 0x82;
    unixtimetemp2[2] = 0x7D;
    unixtimetemp2[3] = 0x17;
   /* unixtimetemp = (unixtimetemp2[0]*0x1000)+(unixtimetemp2[1]*0x0100)+(unixtimetemp2[2]*0x0010)+(unixtimetemp2[3]);*/
    memcpy(&unixtimetemp, &fvalue, sizeof(long int));

    printf("%lx",unixtimetemp);
    getch();
}
htof()
{
    long int dwValue = 0xCDCDCDCD ;/*42eb262c; */
    float fValue=1;

    memcpy(&fValue, &dwValue, sizeof(long int));
    printf("%lx\n",dwValue);
    printf("%f\n", fValue);
    printf("%d\n",strlen(fValue));
    getch();
}

ftoh()
{
    long int dwValue = 0xffffffff;
    float fValue=6;

    memcpy(&dwValue,&fValue,  sizeof(long int));

    printf("%f\n", fValue);
    printf("%lx",dwValue);
    getch();
}

unsigned char AscToHex(unsigned char da)
{
  unsigned char InstHigh = da;

  if((da>='0')&&(da<='9'))
  {

    da = da-'0';
  }

  if((da>='a')&&(da<='z'))
  {

    da = da-'a'+10;
  }
  if((da>='A')&&(da<='Z'))
  {

    da = da-'A'+10;
    InstHigh = da;
  }

  return da;
}
pow_test()
{   unsigned char Valtemp1[]={"122.125"};
    unsigned char j;
    float Valtemp2;
    for(j=0;j<3;j++)
   {
     Valtemp2 += AscToHex(Valtemp1[j])*(pow(10,2-j));
   }
   for(j=0;j<4;j++)
   {
     Valtemp2 += AscToHex(Valtemp1[j+4])*(pow(10,-j-1));
   }
   printf("%f\n",Valtemp2);
   getch();

}

void tst_pow (void)
{
  char base;
  char power;
  float y;

  base  = 2;
  power = -2;

  y = pow (base, power);                   /* y = 256 */

  printf ("%d ^ %d = %f\n", base, power, y);
  getch();
}