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NAME

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

SYNOPSIS

       #include <netdb.h>

       struct netent *getnetent(void);

       struct netent *getnetbyname(const char *name);

       struct netent *getnetbyaddr(uint32_t net, int type);

       void setnetent(int stayopen);

       void endnetent(void);

DESCRIPTION

       The getnetent()  function  reads  the  next  entry  from  the  networks
       database  and  returns  a  netent  structure  containing the broken-out
       fields from the entry.  A connection  is  opened  to  the  database  if
       necessary.

       The  getnetbyname()  function  returns a netent structure for the entry
       from the database that matches the network name.

       The getnetbyaddr() function returns a netent structure  for  the  entry
       from  the  database  that  matches the network number net of type type.
       The net argument must be in host byte order.

       The setnetent() function opens a connection to the database,  and  sets
       the  next  entry  to the first entry.  If stayopen is nonzero, then the
       connection to the database will not be closed between calls to  one  of
       the getnet*() functions.

       The endnetent() function closes the connection to the database.

       The netent structure is defined in <netdb.h> as follows:

           struct netent {
               char      *n_name;     /* official network name */
               char     **n_aliases;  /* alias list */
               int        n_addrtype; /* net address type */
               uint32_t   n_net;      /* network number */
           }

       The members of the netent structure are:

       n_name The official name of the network.

       n_aliases
              A NULL-terminated list of alternative names for the network.

       n_addrtype
              The type of the network number; always AF_INET.

       n_net  The network number in host byte order.

RETURN VALUE

       The  getnetent(),  getnetbyname() and getnetbyaddr() functions return a
       pointer to a statically allocated netent structure, or a  NULL  pointer
       if an error occurs or the end of the file is reached.

FILES

       /etc/networks
              networks database file

CONFORMING TO

       4.3BSD, POSIX.1-2001.

NOTES

       In glibc versions before 2.2, the net argument of getnetbyaddr() was of
       type long.

SEE ALSO

       getnetent_r(3), getprotoent(3), getservent(3)
       RFC 1101

COLOPHON

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