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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  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