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(uint32_t net, int type);
void setnetent(int stayopen);
void endnetent(void);
DESCRIPTION
The getnetent() function reads the next entry from the networks database and returns a netent structure containing the broken-out fields from the entry. A connection is opened to the database if necessary.
The getnetbyname() function returns a netent structure for the entry from the database that matches the network name.
The getnetbyaddr() function returns a netent structure for the entry from the database that matches the network number net of type type. The net argument must be in host byte order.
The setnetent() function opens a connection to the database, and sets the next entry to the first entry. If stayopen is non-zero, then the connection to the database will not be closed between calls to one of the getnet*() functions.
The endnetent() function closes the connection to the database.
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 */ uint32_t n_net; /* network number */ }
The members of the netent structure are:
| n_name | The official name of the network. |
| n_aliases | |
| A NULL-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 a pointer to a statically allocated 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
4.3BSD, POSIX.1-2001.
NOTES
In glibc versions before 2.2, the net argument of getnetbyaddr() was of type long.
SEE ALSO
getnetent_r(3), getprotoent(3), getservent(3) RFC 1101
COLOPHON
This page is part of release 3.23 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.
