getnetent

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 endnetent() 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

4.3BSD, POSIX.1-2001.

SEE ALSO

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