GETPROTOENT(3) BSD Programmer's Manual GETPROTOENT(3)
getprotoent, getprotoent_r, getprotobynumber, getprotobynumber_r,
getprotobyname, getprotobyname_r, setprotoent, setprotoent_r,
endprotoent, endprotoent_r - get protocol entry
#include <netdb.h>
struct protoent *
getprotoent(void);
int
getprotoent_r(struct protoent *protoent,
struct protoent_data *protoent_data);
struct protoent *
getprotobyname(const char *name);
int
getprotobyname_r(const char *name, struct protoent *protoent,
struct protoent_data *protoent_data);
struct protoent *
getprotobynumber(int proto);
int
getprotobynumber_r(int proto, struct protoent *protoent,
struct protoent_data *protoent_data);
void
setprotoent(int stayopen);
void
setprotoent_r(int stayopen, struct protoent_data *protoent_data);
void
endprotoent(void);
void
endprotoent_r(struct protoent_data *protoent_data);
The getprotoent(), getprotobyname(), and getprotobynumber() functions
each return a pointer to an object with the following structure contain-
ing the broken-out fields of a line in the network protocol database,
/etc/protocols.
struct protoent {
char *p_name; /* official name of protocol */
char **p_aliases; /* alias list */
int p_proto; /* protocol number */
};
The members of this structure are:
p_name The official name of the protocol.
p_aliases A null-terminated list of alternate names for the protocol.
p_proto The protocol number.
The getprotoent() function reads the next line of the file, opening the
file if necessary.
The setprotoent() function opens and rewinds the file. If the stayopen
flag is non-zero, the protocol database will not be closed after each
call to getprotobyname() or getprotobynumber().
The endprotoent() function closes the file.
The getprotobyname() and getprotobynumber() functions sequentially search
from the beginning of the file until a matching protocol name or protocol
number is found, or until EOF is encountered.
The getprotoent_r(), getprotobyport_r(), getprotobyname_r(),
setprotoent_r(), and endprotoent_r() functions are reentrant versions of
the above functions that take a pointer to a protoent_data structure
which is used to store state information. The structure must be zero-
filled before it is used and should be considered opaque for the sake of
portability.
The getprotoent_r(), getprotobyport_r(), and getprotobyname_r() functions
also take a pointer to a protoent structure which is used to store the
results of the database lookup.
The getprotoent(), getprotobyport(), and getprotobyname() functions re-
turn a pointer to a protoent structure on success or a null pointer if
end-of-file is reached or an error occurs.
The getprotoent_r(), getprotobyport_r(), and getprotobyname_r() functions
return 0 on success or -1 if end-of-file is reached or an error occurs.
/etc/protocols
protocols(5)
The getprotoent(), getprotobynumber(), getprotobyname(), setprotoent(),
and endprotoent() functions conform to IEEE Std 1003.1-2004 ("POSIX.1").
The getprotoent_r(), getprotobyport_r(), getprotobyname_r(),
setprotoent_r(), and endprotoent_r() functions are not currently stand-
ardized. This implementation follows the API used by HP, IBM, and Digi-
tal.
The getprotoent(), getprotobynumber(), getprotobyname(), setprotoent(),
and endprotoent() functions appeared in 4.2BSD.
The getprotoent_r(), getprotobyport_r(), getprotobyname_r(),
setprotoent_r(), and endprotoent_r() functions appeared in OpenBSD 3.7.
The non-reentrant functions use a static data space; if the data is need-
ed for future use, it should be copied before any subsequent calls
overwrite it. Only the Internet protocols are currently understood.
MirBSD #10-current October 13, 2004 1