If you are reading a host's address from the COMMAND line, you may not know if you have an aaa.bbb.ccc.ddd style address, or a host.domain.com style address. What I do with these, is first try to use it as a aaa.bbb.ccc.ddd type address, and if that fails, then do a NAME lookup on it. Here is an example.

/* Converts ascii text to in_addr struct.

/* NULL is returned if the

address can not be found. */

struct in_addr *atoaddr(char *address) {

struct hostent *host;

static struct in_addr saddr;

/* First try it as aaa.bbb.ccc.ddd. */

saddr.s_addr = inet_addr(address);

if (saddr.s_addr != -1) {

return &saddr;

}

host = gethostbyname(address);

if (host != NULL) {

return (struct in_addr *) *host->h_addr_list;

}

return NULL;

}

If you are reading a host's address from the command line, you may not know if you have an aaa.bbb.ccc.ddd style address, or a host.domain.com style address. What I do with these, is first try to use it as a aaa.bbb.ccc.ddd type address, and if that fails, then do a name lookup on it. Here is an example.

/* Converts ascii text to in_addr struct.

/* NULL is returned if the

address can not be found. */

struct in_addr *atoaddr(char *address) {

struct hostent *host;

static struct in_addr saddr;

/* First try it as aaa.bbb.ccc.ddd. */

saddr.s_addr = inet_addr(address);

if (saddr.s_addr != -1) {

return &saddr;

}

host = gethostbyname(address);

if (host != NULL) {

return (struct in_addr *) *host->h_addr_list;

}

return NULL;

}