getservent, getservbyport, getservbyname, setservent, endservent -
get service entry

#include <netdb.h>

struct servent *getservent()

struct servent *getservbyname(name, proto)
const char *name, *proto;

struct servent *getservbyport(port, proto)
int port; const char *proto;

void setservent(stayopen)
int stayopen

void endservent()

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 */
fchar *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

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

Getservent reads the next line of the file, opening the file if

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 .IR 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.


getprotoent(3), services(5)

Null pointer (0) returned on EOF or error.

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.