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

NAME getnetent, getnetbyname, getnetbyaddr, setnetent, endnetent - get net- work 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/net- works 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

BSD 1993-05-15 GETNETENT(3)