networks(5) [opendarwin 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)
Check Out this Related Man Page
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)