networks(5) [x11r4 man page]

NETWORKS(5)                                                 Linux System Administration                                                NETWORKS(5)

NAME

       networks - network name information

DESCRIPTION

       The  file  /etc/networks is a plain ASCII file that describes known DARPA networks and symbolic names for these networks.  Each line repre-
       sents a network and has the following structure:

              name number aliases ...

       where the fields are delimited by spaces or tabs.  Empty lines are ignored.  The hash character (#) indicates the start of a comment:  this
       character, and the remaining characters up to the end of the current line, are ignored by library functions that process the file.

       The field descriptions are:

       name   The  symbolic name for the network.  Network names can contain any printable characters except white-space characters or the comment
              character.

       number The official number for this network in numbers-and-dots notation (see inet(3)).  The trailing ".0" (for the host component  of  the
              network address) may be omitted.

       aliases
              Optional aliases for the network.

       This  file is read by the route(8) and netstat(8) utilities.  Only Class A, B or C networks are supported, partitioned networks (i.e., net-
       work/26 or network/28) are not supported by this facility.

FILES

       /etc/networks
              The networks definition file.

SEE ALSO

       getnetbyaddr(3), getnetbyname(3), getnetent(3), netstat(8), route(8)

COLOPHON

       This page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and  the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU
/Linux                                                           2008-09-04                                                         NETWORKS(5)

GETNETENT(3)						     Linux Programmer's Manual						      GETNETENT(3)

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(long net, int type);

       void setnetent(int stayopen);

       void endnetent(void);

DESCRIPTION

       The  getnetent()  function  reads the next line from the file /etc/networks and returns a structure netent containing the broken out fields
       from the line.  The /etc/networks file is opened if necessary.

       The getnetbyname() function returns a netent structure for the line from /etc/networks that matches the network name.

       The getnetbyaddr() function returns a netent structure for the line that matches the network number net of type type.

       The setnetent() function opens and rewinds the /etc/networks file.  If stayopen is true (1), then the file will not be closed between calls
       to getnetbyname() and getnetbyaddr().

       The endservent() function closes /etc/networks.

       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 */
		      unsigned long int n_net;	/* network number */
	      }

       The members of the netent 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; always AF_INET.

       n_net  The network number in host byte order.

RETURN VALUE

       The  getnetent(),  getnetbyname() and getnetbyaddr() functions return the 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

       BSD 4.3

SEE ALSO

       getprotoent(3), getservent(3), networks(5)
       RFC 1101

BSD
								    1993-05-15							      GETNETENT(3)