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GETNETENT(3)             BSD Library Functions Manual             GETNETENT(3)

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

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <netdb.h>

     struct netent *
     getnetent();

     struct netent *
     getnetbyname(const char *name);

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

     setnetent(int stayopen);

     endnetent();

DESCRIPTION
     The getnetent(), getnetbyname(), and getnetbyaddr() functions each return
     a pointer to an object with the following structure containing the
     broken-out fields of a line in the network data base as described in
     networks(5).

           struct  netent {
                   char            *n_name;        /* official name of net */
                   char            **n_aliases;    /* alias list */
                   int             n_addrtype;     /* net number type */
                   uint32_t        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 alternative 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.

     The getnetent() function reads the next line of the file, opening the
     file if necessary.

     The setnetent() function opens and rewinds the file.  If the stayopen
     flag is non-zero, the net data base will not be closed after each call to
     getnetbyname() or getnetbyaddr().

     The endnetent() function closes the file.

     The getnetbyname() function 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

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

SEE ALSO
     networks(5), nsswitch.conf(5)

HISTORY
     The getnetent(), getnetbyaddr(), getnetbyname(), setnetent(), and
     endnetent() functions appeared in 4.2BSD.

BUGS
     The data space used by these functions is static; if future use requires
     the data, it should be copied before any subsequent calls to these
     functions overwrite it.  Only Internet network numbers are currently
     understood.  Expecting network numbers to fit in no more than 32 bits is
     probably naive.

BSD                               May 8, 2004                              BSD
NAME | LIBRARY | SYNOPSIS | DESCRIPTION | FILES | DIAGNOSTICS | SEE ALSO | HISTORY | BUGS