c计算所有可能的子网

我正在尝试使用我的网络IP和掩码计算所有可能的子网：

char *net = "192.168.1.0"
char *mask = "255.255.255.0"

in_addr_t _net = inet_addr(net);
in_addr_t _mask = inet_addr(mask);
int possibleHosts = ntohl(~_mask);  // = 255


for (int i=0; i<possibleHosts; i++) {    //From 0 to 255
    in_addr_t subnet = (_mask & _net) | i;    // should calculate the subnets from 192.168.1.0 to 192.168.1.255
    struct in_addr in;
    in.s_addr = subnet;
    char *test = inet_ntoa(in);
    printf("%s\n", test);    //always prints 192.168.1.0???

}

char*net=“192.168.1.0”
char*mask=“255.255.255.0”
in_addr_t_net=inet_addr（net）；
in_addr_t_mask=inet_addr（mask）；
int-possibleHosts=ntohl（~\u掩码）；/=255
对于（inti=0；i核心概念

mask32 = 0xFFFFFFFF = (~0 << 0);
mask31 = 0xFFFFFFFE = (~0 << 1);
mask30 = 0xFFFFFFFB = (~0 << 2);

mask01 = 0x00000000 = (~0 << 31);

[Note: ~0 means inverting all bits of 0, i.e. 0xFFFFFFFF. "<<" means left bit shift.]

假设您想保留现有的代码（这是一个很大的假设），请记住
\u net
和
\u mask
都仍然处于网络顺序，因此您的OR'd in子地址也需要保留

const char *net = "192.168.1.0";
const char *mask = "255.255.255.0";

in_addr_t _net = inet_addr(net);
in_addr_t _mask = inet_addr(mask);
int possibleHosts = ntohl(~_mask);


for (int i=0; i<possibleHosts; i++)
{
    in_addr_t subnet = (_mask & _net) | htonl(i); // <<== must be network-order
    struct in_addr in;
    in.s_addr = subnet;
    char *test = inet_ntoa(in);
    printf("%s\n", test);

}

在进入循环之前打印
\u net
和
\u mask
可能会对您的问题有所帮助。或者更好的是，调试器可能会提供同样的信息。考虑到此代码不会编译，这并不会使它变得更容易。使用您提供的代码，我得到了输出192.168.1.0 193.168.1.0 194.168.1.0 195.168.1.0 196.168.1.0 197.168.1.0 198.168.1.0等。如果您没有收到此输出，请更新您的问题以提供更多信息。我收到了相同的输出，但应该是192.168.1.0、192.168.1.1、192.168.1.2…192.168.1.255听起来像是big-endian vs.little-endian哦，我不知道htonl的存在。我正在尝试类似于\u addr\t子网中的
（_mask&_net）|它是
ntohl（）
的正反面。此外，如果上面的代码在
i
的加法器中使用
，它甚至是可移植的（听起来像是扭曲的）。
// A function to convert mask from number format to string format.
// See http://www.allredroster.com/iptodec.htm for reference
// Example: maskAsString( 0xC0A80100 ) --> "192.168.1.0"
char const * maskAsString( uint32_t mask );

// .. and also the inverse function
uint32_t stringAsMask( char const * maskString );

const char *net = "192.168.1.0";
const char *mask = "255.255.255.0";

in_addr_t _net = inet_addr(net);
in_addr_t _mask = inet_addr(mask);
int possibleHosts = ntohl(~_mask);


for (int i=0; i<possibleHosts; i++)
{
    in_addr_t subnet = (_mask & _net) | htonl(i); // <<== must be network-order
    struct in_addr in;
    in.s_addr = subnet;
    char *test = inet_ntoa(in);
    printf("%s\n", test);

}

192.168.1.0
192.168.1.1
192.168.1.2
192.168.1.3
192.168.1.4
192.168.1.5
192.168.1.6
192.168.1.7
192.168.1.8
192.168.1.9
192.168.1.10
192.168.1.11
192.168.1.12
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192.168.1.14
192.168.1.15
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192.168.1.18
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192.168.1.25
192.168.1.26
192.168.1.27
192.168.1.28
192.168.1.29
192.168.1.30
192.168.1.31
192.168.1.32
192.168.1.33
192.168.1.34
192.168.1.35
192.168.1.36
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