GETPROTOENT(3) BSD Programmer's Manual GETPROTOENT(3)NAME
getprotoent, getprotobynumber, getprotobyname, setprotoent, endprotoent -
get protocol entry
SYNOPSIS
#include <netdb.h>
struct protoent *
getprotoent();
struct protoent *
getprotobyname(char *name);
struct protoent *
getprotobynumber(int proto);
setprotoent(int stayopen);
endprotoent();
DESCRIPTION
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 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 zero 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 net data base will not be closed after each call to
getprotobyname() or getprotobynumber().
The endprotoent() function closes the file.
The getprotobyname() function 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.
RETURN VALUES
Null pointer (0) returned on EOF or error.
FILES
/etc/protocols
SEE ALSOprotocols(5)HISTORY
The getprotoent(), getprotobynumber(), getprotobyname(), setprotoent(),
and endprotoent() functions appeared in 4.2BSD.
BUGS
These functions use a static data space; if the data is needed for future
use, it should be copied before any subsequent calls overwrite it. Only
the Internet protocols are currently understood.
The getprotoent(), getprotobynumber(), getprotobyname(), setprotoent(),
and endprotoent() functions may not be safely called concurrently from
multiple threads, e.g., the interfaces described by pthreads(3).
4.2 Berkeley Distribution June 4, 1993 2
