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explain_munmap(3)	   Library Functions Manual	     explain_munmap(3)

NAME
       explain_munmap -	explain	munmap(2) errors

SYNOPSIS
       #include	<libexplain/munmap.h>
       const char *explain_munmap(void *data, size_t data_size);
       const char *explain_errno_munmap(int errnum, void *data,	size_t
       data_size);
       void explain_message_munmap(char	*message, int message_size, void
       *data, size_t data_size);
       void explain_message_errno_munmap(char *message,	int message_size, int
       errnum, void *data, size_t data_size);

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

   explain_munmap
       const char *explain_munmap(void *data, size_t data_size);

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

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

       data_size
	       The original data_size, exactly as passed to the	munmap(2) sys-
	       tem 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:
	      if (munmap(data, data_size) < 0)
	      {
		  fprintf(stderr, "%s\n", explain_munmap(data, data_size));
		  exit(EXIT_FAILURE);
	      }

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

   explain_errno_munmap
       const char *explain_errno_munmap(int errnum, void *data,	size_t
       data_size);

       The  explain_errno_munmap  function is used to obtain an	explanation of
       an error	returned by the	munmap(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.

       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.

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

       data_size
	       The original data_size, exactly as passed to the	munmap(2) sys-
	       tem 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:
	      if (munmap(data, data_size) < 0)
	      {
		  int err = errno;
		  fprintf(stderr, "%s\n", explain_errno_munmap(err, data,
		  data_size));
		  exit(EXIT_FAILURE);
	      }

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

   explain_message_munmap
       void explain_message_munmap(char	*message, int message_size, void
       *data, size_t data_size);

       The explain_message_munmap function is used to obtain an	explanation of
       an error	returned by the	munmap(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.

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

       data_size
	       The original data_size, exactly as passed to the	munmap(2) sys-
	       tem call.

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

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

   explain_message_errno_munmap
       void explain_message_errno_munmap(char *message,	int message_size, int
       errnum, void *data, size_t data_size);

       The explain_message_errno_munmap	function is used to obtain an explana-
       tion  of	 an error returned by the munmap(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.

       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.

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

       data_size
	       The original data_size, exactly as passed to the	munmap(2) sys-
	       tem call.

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

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

SEE ALSO
       munmap(2)
	       unmap a file or device from memory

       explain_munmap_or_die(3)
	       unmap a file or device from memory and report errors

COPYRIGHT
       libexplain version 1.3
       Copyright (C) 2010 Peter	Miller

							     explain_munmap(3)

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO | COPYRIGHT

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