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explain_setbuffer(3)	   Library Functions Manual	  explain_setbuffer(3)

NAME
       explain_setbuffer - explain setbuffer(3)	errors

SYNOPSIS
       #include	<libexplain/setbuffer.h>
       const char *explain_setbuffer(FILE *fp, char *data, size_t size);
       const char *explain_errno_setbuffer(int errnum, FILE *fp, char *data,
       size_t size);
       void explain_message_setbuffer(char *message, int message_size, FILE
       *fp, char *data,	size_t size);
       void explain_message_errno_setbuffer(char *message, int message_size,
       int errnum, FILE	*fp, char *data, size_t	size);

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

   explain_setbuffer
       const char *explain_setbuffer(FILE *fp, char *data, size_t size);

       The  explain_setbuffer  function	is used	to obtain an explanation of an
       error returned by the setbuffer(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.

       fp      The  original  fp, exactly as passed to the setbuffer(3)	system
	       call.

       data    The original data, exactly as passed to the setbuffer(3)	system
	       call.

       size    The original size, exactly as passed to the setbuffer(3)	system
	       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:
	      void result = setbuffer(fp, data,	size);
	      if (result < 0)
	      {
		  fprintf(stderr, "%s\n", explain_setbuffer(fp,	data, size));
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_setbuffer
       const char *explain_errno_setbuffer(int errnum, FILE *fp, char *data,
       size_t size);

       The explain_errno_setbuffer function is used to obtain  an  explanation
       of  an  error  returned by the setbuffer(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.

       fp      The  original  fp, exactly as passed to the setbuffer(3)	system
	       call.

       data    The original data, exactly as passed to the setbuffer(3)	system
	       call.

       size    The original size, exactly as passed to the setbuffer(3)	system
	       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:
	      void result = setbuffer(fp, data,	size);
	      if (result < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_setbuffer(err, fp,
		  data,	size));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_setbuffer
       void explain_message_setbuffer(char *message, int message_size, FILE
       *fp, char *data,	size_t size);

       The explain_message_setbuffer function is used to obtain	an explanation
       of an error returned by the setbuffer(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.

       fp      The original fp,	exactly	as passed to the  setbuffer(3)	system
	       call.

       data    The original data, exactly as passed to the setbuffer(3)	system
	       call.

       size    The original size, exactly as passed to the setbuffer(3)	system
	       call.

       Example:	 This  function	is intended to be used in a fashion similar to
       the following example:
	      void result = setbuffer(fp, data,	size);
	      if (result < 0)
	      {
		  char message[3000];
		  explain_message_setbuffer(message, sizeof(message), fp,
		  data,	size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_errno_setbuffer
       void explain_message_errno_setbuffer(char *message, int message_size,
       int errnum, FILE	*fp, char *data, size_t	size);

       The  explain_message_errno_setbuffer  function is used to obtain	an ex-
       planation of an error returned by the setbuffer(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.

       fp      The original fp,	exactly	as passed to the  setbuffer(3)	system
	       call.

       data    The original data, exactly as passed to the setbuffer(3)	system
	       call.

       size    The original size, exactly as passed to the setbuffer(3)	system
	       call.

       Example:	 This  function	is intended to be used in a fashion similar to
       the following example:
	      void result = setbuffer(fp, data,	size);
	      if (result < 0)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_setbuffer(message, sizeof(message),
		  err, fp, data, size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

SEE ALSO
       setbuffer(3)
	       stream buffering	operations

       explain_setbuffer_or_die(3)
	       stream buffering	operations and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2010 Peter	Miller

							  explain_setbuffer(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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