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ARCHIVE_WRITE_OPEN(3)  FreeBSD Library Functions Manual	 ARCHIVE_WRITE_OPEN(3)

     archive_write_open, archive_write_open_fd,	archive_write_open_FILE,
     archive_write_open_filename, archive_write_open_memory -- functions for
     creating archives

     Streaming Archive Library (libarchive, -larchive)

     #include <archive.h>

     archive_write_open(struct archive *, void *client_data,
	 archive_open_callback *, archive_write_callback *,
	 archive_close_callback	*);

     archive_write_open_fd(struct archive *, int fd);

     archive_write_open_FILE(struct archive *, FILE *file);

     archive_write_open_filename(struct	archive	*, const char *filename);

     archive_write_open_memory(struct archive *, void *buffer,
	 size_t	bufferSize, size_t *outUsed);

	     Freeze the	settings, open the archive, and	prepare	for writing
	     entries.  This is the most	generic	form of	this function, which
	     accepts pointers to three callback	functions which	will be	in-
	     voked by the compression layer to write the constructed archive.
	     This does not alter the default archive padding.

	     A convenience form	of archive_write_open()	that accepts a file
	     descriptor.  The archive_write_open_fd() function is safe for use
	     with tape drives or other block-oriented devices.

	     A convenience form	of archive_write_open()	that accepts a FILE *
	     pointer.  Note that archive_write_open_FILE() is not safe for
	     writing to	tape drives or other devices that require correct

	     A deprecated synonym for archive_write_open_filename().

	     A convenience form	of archive_write_open()	that accepts a file-
	     name.  A NULL argument indicates that the output should be	writ-
	     ten to standard output; an	argument of "-"	will open a file with
	     that name.	 If you	have not invoked
	     archive_write_set_bytes_in_last_block(), then
	     archive_write_open_filename() will	adjust the last-block padding
	     depending on the file: it will enable padding when	writing	to
	     standard output or	to a character or block	device node, it	will
	     disable padding otherwise.	 You can override this by manually in-
	     voking archive_write_set_bytes_in_last_block() before calling
	     archive_write_open().  The	archive_write_open_filename() function
	     is	safe for use with tape drives or other block-oriented devices.

	     A convenience form	of archive_write_open()	that accepts a pointer
	     to	a block	of memory that will receive the	archive.  The final
	     size_t * argument points to a variable that will be updated after
	     each write	to reflect how much of the buffer is currently in use.
	     You should	be careful to ensure that this variable	remains	allo-
	     cated until after the archive is closed.  This function will dis-
	     able padding unless you have specifically set the block size.
     More information about the	struct archive object and the overall design
     of	the library can	be found in the	libarchive(3) overview.

     Note that the convenience forms above vary	in how they block the output.
     See archive_write_blocksize(3) if you need	to control the block size used
     for writes	or the end-of-file padding behavior.

     To	use this library, you will need	to define and register callback	func-
     tions that	will be	invoked	to write data to the resulting archive.	 These
     functions are registered by calling archive_write_open():

	   typedef int archive_open_callback(struct archive *, void

     The open callback is invoked by archive_write_open().  It should return
     ARCHIVE_OK	if the underlying file or data source is successfully opened.
     If	the open fails,	it should call archive_set_error() to register an er-
     ror code and message and return ARCHIVE_FATAL.

	   typedef la_ssize_t archive_write_callback(struct archive *,
	   void	*client_data, const void *buffer, size_t length)

     The write callback	is invoked whenever the	library	needs to write raw
     bytes to the archive.  For	correct	blocking, each call to the write call-
     back function should translate into a single write(2) system call.	 This
     is	especially critical when writing archives to tape drives.  On success,
     the write callback	should return the number of bytes actually written.
     On	error, the callback should invoke archive_set_error() to register an
     error code	and message and	return -1.

	   typedef int archive_close_callback(struct archive *,	void

     The close callback	is invoked by archive_close when the archive process-
     ing is complete.  The callback should return ARCHIVE_OK on	success.  On
     failure, the callback should invoke archive_set_error() to	register an
     error code	and message and	return ARCHIVE_FATAL.

     Note that if the client-provided write callback function returns a	non-
     zero value, that error will be propagated back to the caller through
     whatever API function resulted in that call, which	may include
     archive_write_header(), archive_write_data(), archive_write_close(),
     archive_write_finish(), or	archive_write_free().  The client callback can
     call archive_set_error() to provide values	that can then be retrieved by
     archive_errno() and archive_error_string().

     These functions return ARCHIVE_OK on success, or ARCHIVE_FATAL.

     Detailed error codes and textual descriptions are available from the
     archive_errno() and archive_error_string()	functions.

     tar(1), libarchive(3), archive_write(3), archive_write_blocksize(3),
     archive_write_filter(3), archive_write_format(3), archive_write_new(3),
     archive_write_set_options(3), cpio(5), mtree(5), tar(5)

FreeBSD	13.0		       February	2, 2012			  FreeBSD 13.0


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