float类型的主机字节和网络字节的转换 ntohf htonf

#include <stdint.h>

uint32_t htonf(float f)
{
    uint32_t p;
    uint32_t sign;

    if (f < 0) { sign = 1; f = -f; }
    else { sign = 0; }
        
    p = ((((uint32_t)f)&0x7fff)<<16) | (sign<<31); // whole part and sign

    p |= (uint32_t)(((f - (int)f) * 65536.0f))&0xffff; // fraction


    return p;
}

float ntohf(uint32_t p)
{
    float f = ((p>>16)&0x7fff); // whole part

    f += (p&0xffff) / 65536.0f; // fraction


    if (((p>>31)&0x1) == 0x1) { f = -f; } // sign bit set


    return f;
}

The above code is sort of a naive implementation that stores a float in a 32-bit number. The high bit (31) is used to store the sign of the number ("1" means negative), and the next seven bits (30-16) are used to store the whole number portion of the float. Finally, the remaining bits (15-0) are used to store the fractional portion of the number.