NAME

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

SYNOPSIS

#include <netdb.h>

struct protoent *getprotoent()

struct protoent *getprotobyname(name)
char *name;

struct protoent *getprotobynumber(proto)
int proto;

setprotoent(stayopen)
int stayopen

endprotoent()

DESCRIPTION

Getprotoent, getprotobyname, and getprotobynumber each return a pointer to a structure of type protoent containing the broken-out fields of a line in the network protocol data base, /etc/protocols. 

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 protocol data base will not be closed after each call to getprotoent (either directly or indirectly through one of the other “getproto” calls). 

Endprotoent closes the file. 

Getprotobyname and getprotobynumber sequentially search from the beginning of the file until a matching protocol name (among either the official names or the aliases) or protocol number is found, or until EOF is encountered. 

If the system is running Yellow Pages (NFS), getprotobyname and getprotobynumber get the host information from the YP server.  See ypserv(1M) and ypfiles(4).

RETURN VALUE

Getprotoent, getprotobyname and getprotobynumber return a null pointer (0) on EOF or when they are unable to open /etc/protocols. 

WARNINGS

All information is contained in a static area so it must be copied if it is to be saved. 

DEPENDENCIES

Implemented on the Series 300 and 800 only. 

AUTHOR

UCB (University of California at Berkeley)

FILES

/etc/protocols

SEE ALSO

ypserv(1M), protocols(4), ypfiles(4). 

INTERNATIONAL SUPPORT

8-bit data, messages. 
 

Hewlett-Packard Company  —  May 11, 2021