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 <>

     struct netent *
     getnetent(void);

     struct netent *
     getnetbyname(const char *name);

     struct netent *
     getnetbyaddr(uint32t 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 containing the bro-
     ken-out fields of a line in the network data base, /etc/networks.

           struct  netent {
                   char            *nname;        /* official name of net */
                   char            **naliases;    /* alias list */
                   int             naddrtype;     /* net number type */
                   unsigned long   nnet;          /* net number */
           };

     The members of this structure are:

     nname      The official name of the network.

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

     naddrtype  The type of the network number returned; currently only
                 AFINET.

     nnet       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 must be AFINET.
     Network numbers are supplied in host order.

FILES
     /etc/networks

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 static; if future use requires
     the data, it should be copied before any subsequent calls to these func-
     tions overwrite it.  Only Internet network numbers are currently under-
     stood.  Expecting network numbers to fit in no more than 32 bits is prob-
     ably naive.

BSD                              June 4, 1993                              BSD