GETNETENT(3N)                                       GETNETENT(3N)



     NAME
          getnetent, getnetbyaddr, getnetbyname, setnetent, endnetent
          - get network entry

     SYNOPSIS
          #include <netdb.h>

          struct netent *getnetent()

          struct netent *getnetbyname(name)
          char *name;

          struct netent *getnetbyaddr(net, type)
          long net;
          int type;

          setnetent(stayopen)
          int stayopen;

          endnetent()

     DESCRIPTION
          Getnetent, getnetbyname, and getnetbyaddr each return a
          pointer to an object with the following structure containing
          the broken-out fields of a line in the network data base,
          /etc/networks.

               struct    netent {
                    char      *n_name;  /* official name of net */
                    char      **n_aliases;   /* alias list */
                    int       n_addrtype;    /* net number type */
                    unsigned long  n_net;         /* net number */
               };

          The members of this structure are:

          n_name      The official name of the network.

          n_aliases   A zero terminated list of  alternate  names  for
                      the network.

          n_addrtype  The  type  of  the  network   number   returned;
                      currently only AF_INET.

          n_net       The  network  number.    Network   numbers   are
                      returned in machine byte order.

          Getnetent reads the next line of the file, opening the  file
          if necessary.

          Setnetent opens and rewinds the file.  If the stayopen  flag
          is non-zero, the net data base will not be closed after each



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     GETNETENT(3N)                                       GETNETENT(3N)



          call to getnetbyname or getnetbyaddr.

          Endnetent closes the file.


          Getnetbyname and getnetbyaddr sequentially search  from  the
          beginning  of  the  file  until  a  matching net name or net
          address and type is found,  or  until  EOF  is  encountered.
          Network numbers are supplied in host order.

     FILES
          /etc/networks

     SEE ALSO
          networks(5)

     DIAGNOSTICS
          Null pointer (0) returned on EOF or error.

     BUGS
          All information is contained in a static area so it must  be
          copied  if it is to be saved.  Only Internet network numbers
          are currently understood.  Expecting network numbers to  fit
          in no more than 32 bits is probably naive.

     NOTE
          There are two versions of the primitives documented in  this
          manual entry:  a vanilla version and a Yellow Pages version.
          The programmatic interface of both  versions  is  identical.
          The  vanilla version gets its information from an ASCII file
          in /etc.  The Yellow Pages version knows about Sun's  Yellow
          Pages  distributed  lookup  service.  If you want the Yellow
          Pages  version,  link   the   program   according   to   the
          instructions  for  (3Y) primitives as described in intro(3).
          Refer to ypserv(1M)  and  the  NFS  User's  Guide  for  more
          information about the Yellow Pages.

     ORIGIN
          4.3 BSD
















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