getprotoent(SLIB)

endprotoent, getprotoent, getprotobynumber, getprotobyname, setprotoent -- get protocol entry

Syntax

cc ... -lsocket

#include  <netdb.h>

struct protoent *
getprotoent()

struct protoent *
getprotobyname(name)
const char *name;

struct protoent *
getprotobynumber(proto)
int proto;

int
setprotoent(stayopen)
int stayopen;

void
endprotoent()

Description

getprotoent, getprotobyname, and getprotobynumber each returns 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.

   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.

getprotoent reads the next line of the file, opening the file if necessary.

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 getprotobyname or getprotobynumber.

endprotoent closes the file.

getprotobyname and getprotobynumber sequentially search from the beginning of the file until a matching protocol name or protocol number is found, or until EOF is encountered.

Files

/etc/protocols

Diagnostics

A null pointer (0) is returned on EOF or error.

Limitations