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

NAME
     getnetent, getnetbyaddr, getnetbyname, setnetent, endnetent -- get net-
     work entry

LIBRARY
     Standard C Library (libc, -lc)

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(), getnetbyname(), and getnetbyaddr() functions each return
     a pointer to an object with the following structure describing an inter-
     net network.  This structure contains information obtained from
     opendirectoryd(8), including records in /etc/networks.

           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 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.

     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.  The type argument must be
     AF_INET.  Network numbers are supplied in host order.

FILES
     /etc/networks
     /etc/resolv.conf

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

SEE ALSO
     networks(5)

     RFC 1101

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

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

BSD                              June 4, 1993                              BSD