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C Interface
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
struct netent *getnetent ()
struct netent *getnetbyname (name)
char *name;
struct netent *getnetbyaddr (net, type)
long net;
int type;
setnetent (stayopen)
int stayopen;
endnetent ()
Description
The getnetent, getnetbyname, and getnetbyaddr
subroutines each return a pointer to an object with the following structure.
This structure contains fields found in the network protocol database,
/etc/networks.
struct netent {
char *n_name; /* official name of net */
char **n_aliases; /* alias list */
int n_addrtype; /* net number type */
long n_net; /* net number */
};
The members of this structure are as follows:
- n_name
- The official name of the network.
- n_aliases
- A null-terminated list of alternate names for the network.
- n_addrtype
- The type of the network number returned, always AF_INET.
- n_net
- The network number. Network numbers are returned in machine byte order.
The getnetent subroutine reads the next line of the file, opening the
file if necessary.
The setnetent subroutine opens and rewinds the file. If the
stayopen flag is non-zero, the network database is not closed
after each call to getnetent (either directly, or indirectly through
one of the other getnet calls).
The endnetent subroutine closes the file.
The getnetbyname subroutine sequentially searches from the beginning
of the file until a network name (among either the official names or the
aliases) matching its parameter name is found, or until EOF is
encountered.
The getnetbyaddr subroutine sequentially searches from the beginning
of the file until a network number matching its parameter net
is found, or until EOF is encountered. The parameter net must
be in network order. The parameter type must be the constant
AF_INET.
Network numbers are supplied in host order. (Refer to the
inet section.)
Restrictions
All information is contained in a static area, so it must be copied if it is
to be saved. Only Internet network numbers are currently understood.
Return Value
The getnetent, getnetbyname, and getnetbyaddr
subroutines return a null pointer (0) on EOF or when they are unable to open
NETWORKS.NET.SYS. The getnetbyaddr subroutine also returns a
null pointer if its parameter type is invalid.
MPE/iX Specific
The name of the networks file on MPE/iX is NETWORKS.NET.SYS, as
opposed to /etc/networks on HP-UX.
Author
UCB (University of California at Berkeley)
Files
NETWORKS.NET.SYS
See Also
inet,
networks
[3kRanger: Topics not located]
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