NAME

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

SYNTAX

#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

The getservent, getservbyname, and getservbyport subroutines 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.

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. 

The getservent subroutine reads the next line of the file, opening the file if necessary.

The setservent subroutine opens and rewinds the file.  If the stayopen flag is nonzero, the net data base will not be closed after each call to getservent (either directly, or indirectly through one of the other “getserv” calls).

The endservent subroutine closes the file.

The getservbyname and getservbyport subroutines 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.

RESTRICTIONS

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

RETURN VALUE

Null pointer (0) returned on EOF or error. 

FILES

/etc/services

SEE ALSO

getprotoent(3n), services(5)

Subroutines