NAME

       inet_aton,  inet_addr,  inet_network,  inet_ntoa,  inet_makeaddr, inet_lnaof, inet_netof -
       Internet address manipulation routines

SYNOPSIS

       #include <sys/socket.h>
       #include <netinet/in.h>
       #include <arpa/inet.h>

       int inet_aton(const char *cp, struct in_addr *inp);

       unsigned long int inet_addr(const char *cp);

       unsigned long int inet_network(const char *cp);

       char *inet_ntoa(struct in_addr in);

       struct in_addr inet_makeaddr(int net, int host);

       unsigned long int inet_lnaof(struct in_addr in);

       unsigned long int inet_netof(struct in_addr in);

DESCRIPTION

       inet_aton() converts the Internet host  address  cp  from  the  standard  numbers-and-dots
       notation  into  binary  data  and stores it in the structure that inp points to. inet_aton
       returns nonzero if the address is valid, zero if not.

       The inet_addr() function converts the  Internet  host  address  cp  from  numbers-and-dots
       notation  into  binary  data  in network byte order.  If the input is invalid, INADDR_NONE
       (usually -1)  is  returned.   This  is  an  obsolete  interface  to  inet_aton,  described
       immediately  above;  it  is  obsolete because -1 is a valid address (255.255.255.255), and
       inet_aton provides a cleaner way to indicate error return.

       The inet_network() function extracts the network  number  in  host  byte  order  from  the
       address cp in numbers-and-dots notation.  If the input is invalid, -1 is returned.

       The inet_ntoa() function converts the Internet host address in given in network byte order
       to a string in standard numbers-and-dots notation.  The string is returned in a statically
       allocated buffer, which subsequent calls will overwrite.

       The  inet_makeaddr()  function  makes  an  Internet  host address in network byte order by
       combining the network number net with the local address host in network net, both in local
       host byte order.

       The  inet_lnaof() function returns the local host address part of the Internet address in.
       The local host address is returned in local host byte order.

       The inet_netof() function returns the network number part of the Internet Address in.  The
       network number is returned in local host byte order.

       The   structure   in_addr  as  used  in  inet_ntoa(),  inet_makeaddr(),  inet_lnoaf()  and
       inet_netof() is defined in netinet/in.h as:

              struct in_addr {
                      unsigned long int s_addr;
              }

       Note that on the i80x86 the host byte order is Least Significant Byte first,  whereas  the
       network byte order, as used on the Internet, is Most Significant Byte first.

CONFORMING TO

       BSD 4.3

SEE ALSO

       gethostbyname(3), getnetent(3), inet_ntop(3), inet_pton(3), hosts(5), networks(5)