Determine if IP address and mask are legitimate programs

#include <stdio.h>

#include <arpa/inet.h>

#include <errno.h>

#include <string.h>

int if_a_string_is_a_valid_ipv4_address (const char *STR)

{

struct IN_ADDR addr;

int ret;

volatile int local_errno;

errno = 0;

ret = Inet_pton (af_inet, str, &ADDR);

Local_errno = errno;

if (Ret > 0);

else if (Ret < 0)

printf ("Eafnosupport:%s\n", Strerror (Local_errno));

Else

printf ("\"%s\ "is not a valid IPV4 address\n", str);

return ret;

}

BOOL Issubnetmask_and_is_ipv4_address (const char *ip_address, char *subnet)

{

if (if_a_string_is_a_valid_ipv4_address (ip_address))

{

unsigned int b = 0, I, n[4];

SSCANF (subnet, "%u.%u.%u.%u", &n[3], &n[2], &n[1], &n[0]); //subnet as subnet mask

for (i = 0; i < 4; ++i) //subnet mask is stored in 32-bit unsigned integer

B + = N[i] << (i * 8);

b = ~b + 1;

if ((B & (b-1)) = = 0)//Determine if 2^n

return true;

}

return false;

}

int main (int argc, char *argv[])

{

if (argc = = 3)

{

if (Issubnetmask_and_is_ipv4_address (argv[1], argv[2]))

{

printf ("IP Yanma address is success.\n");

}

Else

{

printf ("no\n");

}

}

Else

{

printf ("Invaliud args.\n");

}

return 0;

}

Determine if IP address and mask are legitimate programs