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explain_realloc(3)	   Library Functions Manual	    explain_realloc(3)

NAME
       explain_realloc - explain realloc(3) errors

SYNOPSIS
       #include	<libexplain/realloc.h>
       const char *explain_realloc(void	*ptr, size_t size);
       const char *explain_errno_realloc(int errnum, void *ptr,	size_t size);
       void  explain_message_realloc(char  *message,  int  message_size,  void
       *ptr, size_t size);
       void explain_message_errno_realloc(char *message, int message_size, int
       errnum, void *ptr, size_t size);

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

   explain_realloc
       const char *explain_realloc(void	*ptr, size_t size);

       The explain_realloc function is used to obtain an explanation of	an er-
       ror returned by the realloc(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.

       This function is	intended to be used in a fashion similar to  the  fol-
       lowing example:
	      void *new_ptr = realloc(ptr, size);
	      if (!new_ptr)
	      {
		  fprintf(stderr, "%s\n", explain_realloc(ptr, size));
		  exit(EXIT_FAILURE);
	      }

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

       ptr     The original ptr, exactly as passed to  the  realloc(3)	system
	       call.

       size    The  original  size, exactly as passed to the realloc(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, 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_realloc
       const char *explain_errno_realloc(int errnum, void *ptr,	size_t size);

       The  explain_errno_realloc function is used to obtain an	explanation of
       an error	returned by the	realloc(3) 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:
	      void *new_ptr = realloc(ptr, size);
	      if (!new_ptr)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_realloc(err, ptr, size));
		  exit(EXIT_FAILURE);
	      }

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

       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.

       ptr     The original ptr, exactly as passed to  the  realloc(3)	system
	       call.

       size    The  original  size, exactly as passed to the realloc(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, 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_realloc
       void  explain_message_realloc(char  *message,  int  message_size,  void
       *ptr, size_t size);

       The explain_message_realloc function may	be used	to  obtain an explana-
       tion of an error	returned by the	realloc(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.

       This function is	intended to be used in a fashion similar to  the  fol-
       lowing example:
	      void *new_ptr = realloc(ptr, size);
	      if (!new_ptr)
	      {
		  char message[3000];
		  explain_message_realloc(message, sizeof(message), ptr, size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

       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.

       ptr     The  original  ptr,  exactly as passed to the realloc(3)	system
	       call.

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

   explain_message_errno_realloc
       void explain_message_errno_realloc(char *message, int message_size, int
       errnum, void *ptr, size_t size);

       The explain_message_errno_realloc function may be used to obtain	an ex-
       planation  of  an  error	 returned  by the realloc(3) 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:
	      void *new_ptr = realloc(ptr, size);
	      if (!new_ptr)
	      {
		  int err = errno;
		  char message[3000];
		  explain_message_errno_realloc(message, sizeof(message), err, ptr, size);
		  fprintf(stderr, "%s\n", message);
		  exit(EXIT_FAILURE);
	      }

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

       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.

       ptr     The  original  ptr,  exactly as passed to the realloc(3)	system
	       call.

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

SEE ALSO
       realloc(3)
	       Allocate	and free dynamic memory

       explain_realloc_or_die(3)
	       Allocate	and free dynamic memory	and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2009 Peter	Miller

							    explain_realloc(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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