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explain_getaddrinfo(3)	   Library Functions Manual	explain_getaddrinfo(3)

NAME
       explain_getaddrinfo - explain getaddrinfo(3) errors

SYNOPSIS
       #include	<libexplain/getaddrinfo.h>
       const  char  *explain_errcode_getaddrinfo(int errnum, const char	*node,
       const char *service, const  struct  addrinfo  *hints,  struct  addrinfo
       **res);
       void   explain_message_errcode_getaddrinfo(char	 *message,   int  mes-
       sage_size, int errnum, const char *node,	 const	char  *service,	 const
       struct addrinfo *hints, struct addrinfo **res);

DESCRIPTION
       These  functions	may be used to obtain explanations for errors returned
       by the getaddrinfo(3) system call.

   explain_errcode_getaddrinfo
       const char *explain_errcode_getaddrinfo(int errnum, const  char	*node,
       const  char  *service,  const  struct  addrinfo *hints, struct addrinfo
       **res);

       The explain_errcode_getaddrinfo function	is used	to obtain an  explana-
       tion of an error	returned by the	getaddrinfo(3) system call.  The least
       the message will	contain	is the	value  of  gai_strerror(errcode),  but
       usually	it  will  do much better, and indicate the underlying cause in
       more detail.

       This function is	intended to be used in a fashion similar to  the  fol-
       lowing example:
	      int errcode = getaddrinfo(node, service, hints, res);
	      if (errncode == GAI_SYSTEM)
		  errcode = errno;
	      if (errcode)
	      {
		  fprintf(stderr, "%s\n", explain_errcode_getaddrinfo(errcode,
		      node, service, hints, res));
		  exit(EXIT_FAILURE);
	      }

       The   above   code   example   is   available   as  the	explain_getad-
       drinfo_or_die(3)	function.

       errnum  The error value to be decoded, usually obtained from the	 errno
	       global  variable	 just before this function is called.  This is
	       necessary if you	need to	call any code between the system  call
	       to  be explained	and this function, because many	libc functions
	       will alter the value of errno.

       node    The original node, exactly as passed to the getaddrinfo(3) sys-
	       tem call.

       service The  original  service, exactly as passed to the	getaddrinfo(3)
	       system call.

       hints   The original hints, exactly as  passed  to  the	getaddrinfo(3)
	       system call.

       res     The  original res, exactly as passed to the getaddrinfo(3) sys-
	       tem call.

       Returns:
	       The message explaining  the  error.   This  message  buffer  is
	       shared by all libexplain	functions which	do not supply a	buffer
	       in their	argument list.	This will be overwritten by  the  next
	       call  to	 any libexplain	function which shares this buffer, in-
	       cluding other threads.

       Note: This function is not thread safe, because it shares a return buf-
       fer across all threads, and many	other functions	in this	library.

   explain_message_errno_getaddrinfo
       void explain_message_errno_getaddrinfo(char *message, int message_size,
       int errnum, const char *node, const char	 *service,  const  struct  ad-
       drinfo *hints, struct addrinfo **res);

       The explain_message_errno_getaddrinfo function may be used to obtain an
       explanation of an error returned	by  the	 getaddrinfo(3)	 system	 call.
       The  least  the	message	will contain is	the value of strerror(errnum),
       but usually it will do much better, and indicate	the  underlying	 cause
       in more detail.

       This  function  is intended to be used in a fashion similar to the fol-
       lowing example:
	      int errcode = getaddrinfo(node, service, hints, res);
	      if (errnode == EAI_SYSTEM)
		  errcode = errno;
	      if (errcode)
	      {
		  char message[3000];
		  explain_message_errcode_getaddrinfo(message, sizeof(message),
		      errcode, node, service, hints, res);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

       The above code example is available pre-packaged	as the	explain_getad-
       drinfo_or_die(3)	function.

       message The  location  in  which	 to  store the returned	message.  If a
	       suitable	message	return buffer is supplied,  this  function  is
	       thread safe.

       message_size
	       The  size  in  bytes  of	the location in	which to store the re-
	       turned message.

       errnum  The error value to be decoded, usually obtained from the	 errno
	       global  variable	 just before this function is called.  This is
	       necessary if you	need to	call any code between the system  call
	       to  be explained	and this function, because many	libc functions
	       will alter the value of errno.

       node    The original node, exactly as passed to the getaddrinfo(3) sys-
	       tem call.

       service The  original  service, exactly as passed to the	getaddrinfo(3)
	       system call.

       hints   The original hints, exactly as  passed  to  the	getaddrinfo(3)
	       system call.

       res     The  original res, exactly as passed to the getaddrinfo(3) sys-
	       tem call.

SEE ALSO
       getaddrinfo(3)
	       network address and

       explain_getaddrinfo_or_die(3)
	       network address and and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2008 Peter	Miller

							explain_getaddrinfo(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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