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explain_fdopendir(3)	   Library Functions Manual	  explain_fdopendir(3)

NAME
       explain_fdopendir - explain fdopendir(3)	errors

SYNOPSIS
       #include	<libexplain/fdopendir.h>
       const char *explain_fdopendir(int fildes);
       const char *explain_errno_fdopendir(int errnum, int fildes);
       void explain_message_fdopendir(char *message, int message_size, int
       fildes);
       void explain_message_errno_fdopendir(char *message, int message_size,
       int errnum, int fildes);

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

   explain_fdopendir
       const char *explain_fdopendir(int fildes);

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

       The  errno global variable will be used to obtain the error value to be
       decoded.

       fildes  The original fildes, exactly as passed to the fdopendir(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,  including
	       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.

       Example:	This function is intended to be	used in	a fashion  similar  to
       the following example:
	      DIR *result = fdopendir(fildes);
	      if (!result)
	      {
		  fprintf(stderr, "%s\n", explain_fdopendir(fildes));
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_fdopendir
       const char *explain_errno_fdopendir(int errnum, int fildes);

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

       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.

       fildes  The original fildes, exactly as passed to the fdopendir(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, including
	       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.

       Example:	 This  function	is intended to be used in a fashion similar to
       the following example:
	      DIR *result = fdopendir(fildes);
	      if (!result)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_fdopendir(err,
		  fildes));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_fdopendir
       void explain_message_fdopendir(char *message, int message_size, int
       fildes);

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

       The errno global	variable will be used to obtain	the error value	to  be
       decoded.

       message The location in which to	store the returned message. If a suit-
	       able 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.

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

       Example:	 This  function	is intended to be used in a fashion similar to
       the following example:
	      DIR *result = fdopendir(fildes);
	      if (!result)
	      {
		  char message[3000];
		  explain_message_fdopendir(message, sizeof(message), fildes);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_errno_fdopendir
       void explain_message_errno_fdopendir(char *message, int message_size,
       int errnum, int fildes);

       The explain_message_errno_fdopendir function is used to obtain  an  ex-
       planation  of  an  error	returned by the	fdopendir(3) system call.  The
       least the message will contain is the  value  of	 strerror(errno),  but
       usually	it  will  do much better, and indicate the underlying cause in
       more detail.

       message The location in which to	store the returned message. If a suit-
	       able 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.

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

       Example:	This function is intended to be	used in	a fashion  similar  to
       the following example:
	      DIR *result = fdopendir(fildes);
	      if (!result)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_fdopendir(message, sizeof(message),
		  err, fildes);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

SEE ALSO
       fdopendir(3)
	       open a directory

       explain_fdopendir_or_die(3)
	       open a directory	and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2009 Peter	Miller

							  explain_fdopendir(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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