GETSERVENT(3N)                       BSD                        GETSERVENT(3N)



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 database, /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  nonzero,
     the  net  database 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(3N), services(5)

DIAGNOSTICS
     getservent, getservbyport, and getservbyname return a NULL pointer (0) on
     EOF or error.  setservent and endservent return 0 upon successful open or
     close of /etc/services, respectively, and -1 upon failure.

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.