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explain_readlink(3)	   Library Functions Manual	   explain_readlink(3)

NAME
       explain_readlink	- explain readlink(2) errors

SYNOPSIS
       #include	<libexplain/readlink.h>
       const  char  *explain_readlink(const char *pathname, char *data,	size_t
       data_size);
       const char *explain_errno_readlink(int errnum,  const  char  *pathname,
       char *data, size_t data_size);
       void  explain_message_readlink(char  *message,  int message_size, const
       char *pathname, char *data, size_t data_size);
       void explain_message_errno_readlink(char	 *message,  int	 message_size,
       int errnum, const char *pathname, char *data, size_t data_size);

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

   explain_readlink
       const char *explain_readlink(const char *pathname, char	*data,	size_t
       data_size);

       The  explain_readlink  function	is used	to obtain an explanation of an
       error returned by the readlink(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.

       This  function  is intended to be used in a fashion similar to the fol-
       lowing example:
	      if (readlink(pathname, data, data_size) <	0)
	      {
		  fprintf(stderr, "%s\n", explain_readlink(pathname, data, data_size));
		  exit(EXIT_FAILURE);
	      }

       pathname
	       The original pathname, exactly as  passed  to  the  readlink(2)
	       system call.

       data    The  original data, exactly as passed to	the readlink(2)	system
	       call.

       data_size
	       The original data_size, exactly as passed  to  the  readlink(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,  in-
	       cluding 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.

   explain_errno_readlink
       const char *explain_errno_readlink(int errnum,  const  char  *pathname,
       char *data, size_t data_size);

       The explain_errno_readlink function is used to obtain an	explanation of
       an error	returned by the	readlink(2) system call.  The least  the  mes-
       sage will contain is the	value of strerror(errnum), but usually it will
       do much better, and indicate the	underlying cause in more detail.

       This function is	intended to be used in a fashion similar to  the  fol-
       lowing example:
	      if (readlink(pathname, data, data_size) <	0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_readlink(err, pathname,	data,
		      data_size));
		  exit(EXIT_FAILURE);
	      }

       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.

       pathname
	       The  original  pathname,	 exactly  as passed to the readlink(2)
	       system call.

       data    The original data, exactly as passed to the readlink(2)	system
	       call.

       data_size
	       The  original  data_size,  exactly as passed to the readlink(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, in-
	       cluding 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.

   explain_message_readlink
       void  explain_message_readlink(char  *message,  int message_size, const
       char *pathname, char *data, size_t data_size);

       The explain_message_readlink function may be used to  obtain an	expla-
       nation  of an error returned by the readlink(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.

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

       This  function  is intended to be used in a fashion similar to the fol-
       lowing example:
	      if (readlink(pathname, data, data_size) <	0)
	      {
		  char message[3000];
		  explain_message_readlink(message, sizeof(message), pathname, data,
		      data_size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

       message The location in which to	store  the  returned  message.	 If  a
	       suitable	 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.

       pathname
	       The  original  pathname,	 exactly  as passed to the readlink(2)
	       system call.

       data    The original data, exactly as passed to the readlink(2)	system
	       call.

       data_size
	       The  original  data_size,  exactly as passed to the readlink(2)
	       system call.

   explain_message_errno_readlink
       void explain_message_errno_readlink(char	 *message,  int	 message_size,
       int errnum, const char *pathname, char *data, size_t data_size);

       The  explain_message_errno_readlink  function  may be used to obtain an
       explanation of an error returned	by the readlink(2) system  call.   The
       least  the  message  will contain is the	value of strerror(errnum), but
       usually it will do much better, and indicate the	 underlying  cause  in
       more detail.

       This  function  is intended to be used in a fashion similar to the fol-
       lowing example:
	      if (readlink(pathname, data, data_size) <	0)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_readlink(message, sizeof(message), err,	pathname,
		      data, data_size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

       message The location in which to	store  the  returned  message.	 If  a
	       suitable	 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.

       pathname
	       The  original  pathname,	 exactly  as passed to the readlink(2)
	       system call.

       data    The original data, exactly as passed to the readlink(2)	system
	       call.

       data_size
	       The  original  data_size,  exactly as passed to the readlink(2)
	       system call.

SEE ALSO
       readlink(2)
	       blah blah blah

       explain_readlink_or_die(3)
	       blah blah blah  and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2008 Peter	Miller

							   explain_readlink(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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