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getrpcbyname(3NSL)   Networking	Services Library Functions  getrpcbyname(3NSL)

NAME
       getrpcbyname,  getrpcbyname_r, getrpcbynumber, getrpcbynumber_r,	getrp-
       cent, getrpcent_r, setrpcent, endrpcent - get RPC entry

SYNOPSIS
       cc [ flag ... ] file ...	-lnsl [	library	... ]
       #include	<rpc/rpcent.h>

       struct rpcent *getrpcbyname(const char *name);

       struct rpcent *getrpcbyname_r(const char	*name, struct rpcent  *result,
       char *buffer, int buflen);

       struct rpcent *getrpcbynumber(const int number);

       struct  rpcent  *getrpcbynumber_r(const	int number, struct rpcent *re-
       sult, char *buffer, int buflen);

       struct rpcent *getrpcent(void);

       struct rpcent *getrpcent_r(struct rpcent	*result, char *buffer, int bu-
       flen);

       void setrpcent(const int	stayopen);

       void endrpcent(void);

DESCRIPTION
       These  functions	 are  used to obtain entries for RPC (Remote Procedure
       Call) services.	An entry may come from any  of	the  sources  for  rpc
       specified in the	/etc/nsswitch.conf file	(see nsswitch.conf(4)).

       getrpcbyname()  searches	 for an	entry with the RPC service name	speci-
       fied by the parameter name.

       getrpcbynumber()	searches for an	entry with the RPC program number num-
       ber.

       The  functions  setrpcent(),  getrpcent(),  and endrpcent() are used to
       enumerate RPC entries from the database.

       setrpcent() sets	(or resets) the	enumeration to the  beginning  of  the
       set  of	RPC  entries.  This function should be called before the first
       call to getrpcent().   Calls  to	 getrpcbyname()	 and  getrpcbynumber()
       leave  the  enumeration	position  in  an indeterminate state.	If the
       stayopen	flag is	non-zero, the system may keep allocated	resources such
       as open file descriptors	until a	subsequent call	to endrpcent().

       Successive  calls  to  getrpcent()  return either successive entries or
       NULL, indicating	the end	of the enumeration.

       endrpcent() may be called to indicate that the caller expects to	do  no
       further RPC entry retrieval operations; the system may then  deallocate
       resources it was	using.	It is still allowed, but possibly  less	 effi-
       cient, for the process to call more RPC entry retrieval functions after
       calling endrpcent().

   Reentrant Interfaces
       The functions getrpcbyname(),  getrpcbynumber(),	 and  getrpcent()  use
       static  storage that is re-used in each call, making these routines un-
       safe for	use in multithreaded applications.

       The functions getrpcbyname_r(), getrpcbynumber_r(),  and	 getrpcent_r()
       provide reentrant interfaces for	these operations.

       Each  reentrant	interface performs the same operation as its non-reen-
       trant counterpart, named	by removing the	 ``_r''	suffix.	 The reentrant
       interfaces,  however,  use  buffers supplied by the caller to store re-
       turned results, and  are	safe for use in	both single-threaded and  mul-
       tithreaded applications.

       Each reentrant interface	takes the same parameters as its non-reentrant
       counterpart, as well as the following additional	parameters.   The  pa-
       rameter result must be a	pointer	to a struct rpcent structure allocated
       by the caller.  On successful completion, the function returns the  RPC
       entry  in  this	structure. The parameter buffer	must be	a pointer to a
       buffer supplied by the caller.  This buffer is used  as	storage	 space
       for the RPC entry data.	All of the pointers within the returned	struct
       rpcent result point to data stored within this buffer (see RETURN  VAL-
       UES).  The  buffer must be large	enough to hold all of the data associ-
       ated with the RPC entry.	The parameter buflen should give the  size  in
       bytes of	the buffer indicated by	buffer.

       For  enumeration	in multithreaded applications, the position within the
       enumeration is a	process-wide property shared by	 all  threads.	setrp-
       cent()  may  be used in a multithreaded application but resets the enu-
       meration	position for all  threads.   If	 multiple  threads  interleave
       calls  to getrpcent_r(),	the threads will enumerate disjoint subsets of
       the RPC entry database.

       Like  their  non-reentrant  counterparts,  getrpcbyname_r()  and	 getr-
       pcbynumber_r()  leave  the  enumeration	position  in  an indeterminate
       state.

RETURN VALUES
       RPC entries are represented by the struct rpcent	structure  defined  in
       <rpc/rpcent.h>:

       struct rpcent {
	  char *r_name;	      /* name of this rpc service
	  char **r_aliases;   /* zero-terminated list of alternate names */
	  int r_number;	      /* rpc program number */
       };

       The  functions  getrpcbyname(), getrpcbyname_r(), getrpcbynumber(), and
       getrpcbynumber_r() each return a	pointer	to a  struct  rpcent  if  they
       successfully locate the requested entry;	otherwise they return NULL.

       The  functions getrpcent() and getrpcent_r() each return	a pointer to a
       struct rpcent if	they successfully enumerate an entry;  otherwise  they
       return NULL, indicating the end of the enumeration.

       The  functions  getrpcbyname(),	getrpcbynumber(),  and getrpcent() use
       static storage, so returned data	must be	 copied	 before	 a  subsequent
       call to any of these functions if the data is to	be saved.

       When  the pointer returned by the reentrant functions getrpcbyname_r(),
       getrpcbynumber_r(), and getrpcent_r() is	non-NULL, it is	 always	 equal
       to the result pointer that was supplied by the caller.

ERRORS
       The reentrant functions	getrpcyname_r(), getrpcbynumber_r() and	getrp-
       cent_r()	will return NULL and set errno to ERANGE if the	length of  the
       buffer supplied by caller is not	large enough to	store the result.  See
       intro(2)	for the	proper usage and interpretation	 of  errno  in	multi-
       threaded	applications.

FILES
       /etc/rpc

       /etc/nsswitch.conf

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |See  "Reentrant Interfaces"  |
       |			     |in DESCRIPTION.		   |
       +-----------------------------+-----------------------------+

SEE ALSO
       rpcinfo(1M), rpc(3NSL), nsswitch.conf(4), rpc(4), attributes(5)

WARNINGS
       The  reentrant  interfaces  getrpcbyname_r(),  getrpcbynumber_r(),  and
       getrpcent_r()  are  included  in	 this  release on an uncommitted basis
       only, and are subject to	change or removal in future minor releases.

NOTES
       Programs	that use the interfaces	described in this manual  page	cannot
       be  linked  statically since the	implementations	of these functions em-
       ploy dynamic loading and	linking	of shared objects at run time.

       When compiling multithreaded applications, see  intro(3), Notes On Mul-
       tithreaded  Applications,  for  information about the use of the	_REEN-
       TRANT flag.

       Use of the enumeration interfaces getrpcent() and getrpcent_r() is dis-
       couraged;  enumeration  may  not	be supported for all database sources.
       The semantics of	enumeration are	discussed further in nsswitch.conf(4).

SunOS 5.9			  20 Feb 1998		    getrpcbyname(3NSL)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | FILES | ATTRIBUTES | SEE ALSO | WARNINGS | NOTES

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