#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);
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 nonzero, 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:
| Interface | Attribute | Value |
| getnetent() | Thread safety |
MT-Unsafe race:netent
race:netentbuf env locale |
| getnetbyname() | Thread safety |
MT-Unsafe race:netbyname
env locale |
| getnetbyaddr() | Thread safety |
MT-Unsafe race:netbyaddr
locale |
|
setnetent(),
endnetent() | Thread safety |
MT-Unsafe race:netent env
locale |
In the above table, netent in race:netent signifies that if any of the functions setnetent(), getnetent(), or endnetent() are used in parallel in different threads of a program, then data races could occur.