inet(3N)                         DG/UX 5.4.2                        inet(3N)


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

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

       struct in_addr inet_addr(cp)
       char *cp;

       unsigned long inet_network(cp)
       char *cp;

       char *inet_ntoa(in)
       struct in_addr in;

       struct in_addr inet_makeaddr(net, lna)
       int net, lna;

       int inet_lnaof(in)
       struct in_addr in;

       int inet_netof(in)
       struct in_addr in;

DESCRIPTION
       inet_addr, inet_network
                 Interpret character strings representing numbers expressed
                 in the Internet standard dot notation, returning numbers
                 suitable for use as Internet addresses and Internet network
                 numbers, respectively.

       inet_ntoa Takes an Internet address and returns an ASCII string
                 representing the address in dot notation.

       inet_makeaddr
                 Takes an Internet network number and a local network
                 address, and constructs an Internet address from it.

       inet_netof, inet_lnaof
                 Break apart Internet host addresses, returning the network
                 number and local network address part, respectively.

       All Internet addresses are returned in network order (bytes ordered
       from left to right).  All network numbers and local address parts are
       returned as machine-format integer values.

   Internet Addresses
       Values specified using the dot notation take one of the following
       forms:

          a.b.c.d



Licensed material--property of copyright holder(s)                         1

inet(3N)                         DG/UX 5.4.2                        inet(3N)


          a.b.c
          a.b
          a

       When four parts are specified, each is interpreted as a byte of data
       and assigned, from left to right, to the four bytes of an Internet
       address.

       When a three-part address is specified, the last part is interpreted
       as a 16-bit quantity and placed in the rightmost two bytes of the
       network address.  This makes the three-part address format convenient
       for specifying Class B network addresses as 128.net.host.

       When a two-part address is supplied, the last part is interpreted as
       a 24-bit quantity and placed in the rightmost three bytes of the
       network address.  This makes the two-part address format convenient
       for specifying Class A network addresses as net.host.

       When only one part is given, the value is stored directly in the
       network address without any byte rearrangement.

       All numbers supplied as parts in a dot notation may be decimal,
       octal, or hexadecimal, as specified in the C language (i.e., a
       leading 0x or 0X implies hexadecimal; otherwise, a leading 0 implies
       octal; otherwise, the number is interpreted as decimal).

SEE ALSO
       gethostent(3N), getnetent(3N), hosts(4), networks(4).

DIAGNOSTICS
       Inet_addr and inet_network return the value -1 for malformed
       requests.

BUGS
       The problem of host byte ordering versus network byte ordering is
       confusing.  There is no simple way to specify Class C network
       addresses, as there is for Classes A and B.  The string returned by
       inet_ntoa resides in a static memory area.



















Licensed material--property of copyright holder(s)                         2