getprotoent(3n)
NAME
getprotoent, getprotobynumber, getprotobyname, setprotoent, endprotoent − get protocol entry
SYNTAX
#include <netdb.h>
struct protoent *getprotoent()
struct protoent *getprotobyname(name)
char *name;
struct protoent *getprotobynumber(proto)
int proto;
setprotoent(stayopen)
int stayopen
endprotoent()
DESCRIPTION
The getprotoent, getprotobyname, and getprotobynumber subroutines each return a pointer to an object with the following structure containing the broken-out fields of a line in the network protocol data base, /etc/protocols.
structprotoent {
char*p_name;/* official name of protocol */
char**p_aliases;/* alias list */
longp_proto;/* protocol number */
};
The members of this structure are:
p_name The official name of the protocol.
p_aliases A zero terminated list of alternate names for the protocol.
p_proto The protocol number.
The getprotoent subroutine reads the next line of the file, opening the file if necessary.
The setprotoent opens and rewinds the file. If the stayopen flag is non-zero, the net data base will not be closed after each call to getprotoent (either directly, or indirectly through one of the other “getproto” calls).
The endprotoent subroutine closes the file.
The getprotobyname and getprotobynumber subroutines sequentially search from the beginning of the file until a matching protocol name or protocol number is found, or until EOF is encountered.
RESTRICTIONS
All information is contained in a static area so it must be copied if it is to be saved. Only the Internet protocols are currently understood.
RETURN VALUE
Null pointer (0) returned on EOF or error.
FILES
/etc/protocols