NAME
getservent, getservbyport, getservbyname, setservent,
endservent - get service entry
SYNOPSIS
#include <netdb.h>
struct servent *getservent()
struct servent *getservbyname(name, proto)
char *name, *proto;
struct servent *getservbyport(port, proto)
int port; char *proto;
setservent(stayopen)
int stayopen
endservent()
DESCRIPTION
Getservent, getservbyname, and getservbyport each return a
pointer to an object with the following structure containing
the broken-out fields of a line in the network services data
base, /etc/services.
struct servent {
char *s_name; /* official name of service */
char **s_aliases; /* alias list */
int s_port; /* port service resides at */
char *s_proto; /* protocol to use */
};
The members of this structure are:
s_name The official name of the service.
s_aliases A zero terminated list of alternate names for the
service.
s_port The port number at which the service resides.
Port numbers are returned in network byte order.
s_proto The name of the protocol to use when contacting
the service.
Getservent reads the next line of the file, opening the file
if necessary.
Setservent opens and rewinds the file. If the stayopen flag
is non-zero, the net data base will not be closed after each
call to getservbyname or getservbyport.
Endservent closes the file.
Getservbyname and getservbyport sequentially search from the
beginning of the file until a matching protocol name or port
number is found, or until EOF is encountered. If a protocol
name is also supplied (non-NULL), searches must also match
the protocol.
FILES
/etc/services
SEE ALSO
getprotoent(3), services(5)
DIAGNOSTICS
Null pointer (0) returned on EOF or error.
BUGS
All information is contained in a static area so it must be
copied if it is to be saved. Expecting port numbers to fit
in a 32 bit quantity is probably naive.