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explain_signalfd(3)	   Library Functions Manual	   explain_signalfd(3)

NAME
       explain_signalfd	- explain signalfd(2) errors

SYNOPSIS
       #include	<libexplain/signalfd.h>
       const char *explain_signalfd(int	fildes,	const sigset_t *mask, int
       flags);
       const char *explain_errno_signalfd(int errnum, int fildes, const
       sigset_t	*mask, int flags);
       void explain_message_signalfd(char *message, int	message_size, int
       fildes, const sigset_t *mask, int flags);
       void explain_message_errno_signalfd(char	*message, int message_size,
       int errnum, int fildes, const sigset_t *mask, int flags);

DESCRIPTION
       These  functions	may be used to obtain explanations for errors returned
       by the signalfd(2) system call.

   explain_signalfd
       const char *explain_signalfd(int	fildes,	const sigset_t *mask, int
       flags);

       The  explain_signalfd  function	is used	to obtain an explanation of an
       error returned by the signalfd(2) 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 signalfd(2) sys-
	       tem call.

       mask    The original mask, exactly as passed to the signalfd(2)	system
	       call.

       flags   The original flags, exactly as passed to	the signalfd(2)	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:
	      int result = signalfd(fildes, mask, flags);
	      if (result < 0)
	      {
		  fprintf(stderr, "%s\n", explain_signalfd(fildes, mask,
		  flags));
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_signalfd
       const char *explain_errno_signalfd(int errnum, int fildes, const
       sigset_t	*mask, int flags);

       The explain_errno_signalfd function is used to obtain an	explanation of
       an error	returned by the	signalfd(2) system call.  The least  the  mes-
       sage  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 signalfd(2)  sys-
	       tem call.

       mask    The  original mask, exactly as passed to	the signalfd(2)	system
	       call.

       flags   The original flags, exactly as passed to	the signalfd(2)	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:
	      int result = signalfd(fildes, mask, flags);
	      if (result < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_signalfd(err, fildes,
		  mask,	flags));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_signalfd
       void explain_message_signalfd(char *message, int	message_size, int
       fildes, const sigset_t *mask, int flags);

       The explain_message_signalfd function is	used to	obtain an  explanation
       of  an  error  returned	by the signalfd(2) 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 signalfd(2) sys-
	       tem call.

       mask    The original mask, exactly as passed to the signalfd(2)	system
	       call.

       flags   The original flags, exactly as passed to	the signalfd(2)	system
	       call.

       Example:	This function is intended to be	used in	a fashion  similar  to
       the following example:
	      int result = signalfd(fildes, mask, flags);
	      if (result < 0)
	      {
		  char message[3000];
		  explain_message_signalfd(message, sizeof(message), fildes,
		  mask,	flags);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_errno_signalfd
       void explain_message_errno_signalfd(char	*message, int message_size,
       int errnum, int fildes, const sigset_t *mask, int flags);

       The explain_message_errno_signalfd function is used to obtain an	expla-
       nation  of an error returned by the signalfd(2) 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.

       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 signalfd(2) sys-
	       tem call.

       mask    The original mask, exactly as passed to the signalfd(2)	system
	       call.

       flags   The original flags, exactly as passed to	the signalfd(2)	system
	       call.

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

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

SEE ALSO
       signalfd(2)
	       create a	file descriptor	for accepting signals

       explain_signalfd_or_die(3)
	       create  a  file descriptor for accepting	signals	and report er-
	       rors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2009 Peter	Miller

							   explain_signalfd(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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