The
getservent(),
getservbyname(), and
getservbyport() functions 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 NULL terminated list of alternative names for the service.
s_port
The port number at which the service resides. Port numbers must be given and are returned in network byte order.
s_proto
The name of the protocol to use when contacting the service.
The
getservent() function reads the next line of the file, opening the file if necessary.
The
setservent() function 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().
The
endservent() function closes the file.
The
getservbyname() and
getservbyport() functions 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.