INET(3N)                COMMAND REFERENCE                INET(3N)



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

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

     u_long inet_addr(cp)
     char *cp;

     u_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
     The routines inet_addr and inet_network each 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.  The routine inet_ntoa takes an
     Internet address and returns an ASCII string representing
     the address in dot (.) notation.  The routine inet_makeaddr
     takes an Internet network number and a local network address
     and constructs an Internet address from it.  The routines
     inet_netof and inet_lnaof break apart Internet host
     addresses, returning the network number and local network
     address part, respectively.

     All Internet address 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:




Printed 5/12/88                                                 1

INET(3N)                COMMAND REFERENCE                INET(3N)



          a.b.c.d
          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.  Note that when an Internet address
     is viewed as a 32-bit integer quantity on the VAX, the bytes
     referred to above appear as d.c.b.a.  That is, VAX bytes are
     ordered from right to left.

     When a three part address is specified, the last part is
     interpreted as a 16-bit quantity and placed in the right
     most 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 right
     most 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 (for example, a leading 0x or 0X implies
     hexadecimal; otherwise, a leading 0 implies octal;
     otherwise, the number is interpreted as decimal).

DIAGNOSTICS
     The value -1 is returned by inet_addr and inet_network for
     malformed requests.

CAVEATS
     The string returned by inet_ntoa resides in a static memory
     area so it must be copied if it is to be saved.

SEE ALSO
     gethostent(3n), getnetent(3n), hosts(5n), and networks(5n).












Printed 5/12/88                                                 2

%%index%%
na:264,182;
sy:446,3393;
de:3839,1946;6121,1420;
di:7541,422;
ca:7963,287;
se:8250,233;
%%index%%000000000121