getservent(3)
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.