GETSERVENT(3N)
NAME
getservent, getservbyport, getservbyname, setservent, endservent − get service entry
USAGE
#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. The structure contains the separated fields of a line in the network services database, /etc/services.
structservent {
char*s_name;/* official name of service */
char**s_aliases;/* alias list */
longs_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 database will not be closed after each call to getservent (either directly or indirectly through one of the other “getserv” calls).
Endservent closes the file.
Getservbyname and getservbyport search sequentially 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.
NOTES
All information is kept in a static area, so you must copy it if you wish to save it.
DIAGNOSTICS
Null pointer (zero) is returned on EOF or error.
FILES
/etc/services