inet(3)                             CLIX                             inet(3)



  NAME

    inet: inet_addr, inet_network, inet_ntoa, inet_makeaddr, inet_lnaof,
    inet_netof - Internet address manipulation functions

  LIBRARY

    Berkeley Software Distribution Library (libbsd.a)

  SYNOPSIS

    #include <sys/types.h>

    #include <sys/socket.h>

    #include <netinet/in.h>

    #include <arpa/inet.h>

    unsigned long inet_addr(
      char *cp );

    unsigned long inet_network(
      char *cp );

    char *inet_ntoa(
      struct in_addr in );

    struct in_addr inet_makeaddr(
      int net,lna );

    int inet_lnaof(
      struct in_addr in );

    int inet_netof(
      struct in_addr in );

  DESCRIPTION

    The inet_addr() and inet_network() functions interpret character strings
    representing numbers expressed in the Internet standard ``.''  notation,
    returning numbers suitable for use as Internet addresses and Internet
    network numbers, respectively.

    The inet_ntoa() function takes an Internet address and returns an ASCII
    string representing the address in ``.'' notation.  The inet_makeaddr()
    function takes an Internet network number and a local network address and
    constructs an Internet address.  The inet_netof() and inet_lnaof()
    functions break apart Internet host addresses, returning the network
    number and local network address part, respectively.




  2/94 - Intergraph Corporation                                              1

  inet(3)                             CLIX                             inet(3)



    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 ``.'' notation assume one of the following
    forms:

    ⊕  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 CLIPPER, the bytes referred to above appear as d.c.b.a.  CLIPPER
    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 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 lqnet.host.

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

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

    Host versus network byte ordering is confusing.  A simple way to specify
    Class C network addresses similarly to that for Classes A and B is needed.
    The string returned by inet_ntoa() resides in a static memory area.

    The inet_addr() function should return a struct in_addr.

  RETURN VALUES

    A value of -1 is returned by the inet_addr() and inet_network() functions
    for malformed requests.



  2                                              Intergraph Corporation - 2/94

  inet(3)                             CLIX                             inet(3)



  RELATED INFORMATION

    Functions:  gethostbyname(3), getnetent(3).

    Files:   hosts(4), networks(4).

















































  2/94 - Intergraph Corporation                                              3