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explain_asprintf(3)	   Library Functions Manual	   explain_asprintf(3)

NAME
       explain_asprintf	- explain asprintf(3) errors

SYNOPSIS
       #include	<libexplain/asprintf.h>
       const char *explain_asprintf(, ...);
       const char *explain_errno_asprintf(int errnum, ,	...);
       void explain_message_asprintf(char *message, int	message_size, ,	...);
       void explain_message_errno_asprintf(char	*message, int message_size,
       int errnum, , ...);

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

   explain_asprintf
       const char *explain_asprintf(, ...);

       The  explain_asprintf  function	is used	to obtain an explanation of an
       error returned by the asprintf(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.

       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;
	      int result = asprintf();
	      if (result < 0 ||	errno != 0)
	      {
		  fprintf(stderr, "%s\n", explain_asprintf());
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_asprintf
       const char *explain_errno_asprintf(int errnum, ,	...);

       The explain_errno_asprintf function is used to obtain an	explanation of
       an  error  returned by the asprintf(3) 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.

       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;
	      int result = asprintf();
	      if (result < 0 ||	errno != 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_asprintf(err, ));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_asprintf
       void explain_message_asprintf(char *message, int	message_size, ,	...);

       The explain_message_asprintf function is	used to	obtain an  explanation
       of  an  error  returned	by the asprintf(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.

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

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

   explain_message_errno_asprintf
       void explain_message_errno_asprintf(char	*message, int message_size,
       int errnum, , ...);

       The explain_message_errno_asprintf function is used to obtain an	expla-
       nation  of an error returned by the asprintf(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.

       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.

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

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

SEE ALSO
       asprintf(3)
	       print to	allocated string

       explain_asprintf_or_die(3)
	       print to	allocated string and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2013 Peter	Miller

							   explain_asprintf(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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