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explain_setlinebuf(3)	   Library Functions Manual	 explain_setlinebuf(3)

NAME
       explain_setlinebuf - explain setlinebuf(3) errors

SYNOPSIS
       #include	<libexplain/setlinebuf.h>
       const char *explain_setlinebuf(FILE *fp);
       const char *explain_errno_setlinebuf(int	errnum,	FILE *fp);
       void explain_message_setlinebuf(char *message, int message_size,	FILE
       *fp);
       void explain_message_errno_setlinebuf(char *message, int	message_size,
       int errnum, FILE	*fp);

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

   explain_setlinebuf
       const char *explain_setlinebuf(FILE *fp);

       The explain_setlinebuf function is used to obtain an explanation	of  an
       error  returned by the setlinebuf(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 setlinebuf(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:
	      errno = 0;
	      void result = setlinebuf(fp);
	      if (result < 0 &&	errno != 0)
	      {
		  fprintf(stderr, "%s\n", explain_setlinebuf(fp));
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_setlinebuf
       const char *explain_errno_setlinebuf(int	errnum,	FILE *fp);

       The explain_errno_setlinebuf function is	used to	obtain an  explanation
       of  an  error returned by the setlinebuf(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 setlinebuf(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:
	      errno = 0;
	      void result = setlinebuf(fp);
	      if (result < 0 &&	errno != 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_setlinebuf(err,	fp));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_setlinebuf
       void explain_message_setlinebuf(char *message, int message_size,	FILE
       *fp);

       The explain_message_setlinebuf function is used to obtain  an  explana-
       tion  of	an error returned by the setlinebuf(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 de-
       tail.

       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 setlinebuf(3)	system
	       call.

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

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

   explain_message_errno_setlinebuf
       void explain_message_errno_setlinebuf(char *message, int	message_size,
       int errnum, FILE	*fp);

       The explain_message_errno_setlinebuf function is	used to	obtain an  ex-
       planation  of  an error returned	by the setlinebuf(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 setlinebuf(3)	system
	       call.

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

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

SEE ALSO
       setlinebuf(3)
	       stream buffering	operations

       explain_setlinebuf_or_die(3)
	       stream buffering	operations and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2010 Peter	Miller

							 explain_setlinebuf(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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