ARCHIVE_WRITE_BLOCKSIZE(3) Introduction to Library Functions

NAME

archive_write_get_bytes_per_block, archive_write_set_bytes_per_block,
archive_write_get_bytes_in_last_block,
archive_write_set_bytes_in_last_block - functions for creating archives

LIBRARY

Streaming Archive Library (libarchive, -larchive)

SYNOPSIS

#include <archive.h>

int
archive_write_get_bytes_per_block(struct archive *);

int
archive_write_set_bytes_per_block(struct archive *,
int bytes_per_block);

int
archive_write_get_bytes_in_last_block(struct archive *);

int
archive_write_set_bytes_in_last_block(struct archive *, int);

DESCRIPTION

archive_write_set_bytes_per_block()
Sets the block size used for writing the archive data. Every
call to the write callback function, except possibly the last
one, will use this value for the length. The default is to use
a block size of 10240 bytes. Note that a block size of zero
will suppress internal blocking and cause writes to be sent
directly to the write callback as they occur.

archive_write_get_bytes_per_block()
Retrieve the block size to be used for writing. A value of -1
here indicates that the library should use default values. A
value of zero indicates that internal blocking is suppressed.

archive_write_set_bytes_in_last_block()
Sets the block size used for writing the last block. If this
value is zero, the last block will be padded to the same size
as the other blocks. Otherwise, the final block will be padded
to a multiple of this size. In particular, setting it to 1
will cause the final block to not be padded. For compressed
output, any padding generated by this option is applied only
after the compression. The uncompressed data is always
unpadded. The default is to pad the last block to the full
block size (note that archive_write_open_filename() will set
this based on the file type). Unlike the other "set"
functions, this function can be called after the archive is
opened.

archive_write_get_bytes_in_last_block()
Retrieve the currently-set value for last block size. A value
of -1 here indicates that the library should use default
values.

RETURN VALUES

archive_write_set_bytes_per_block() and
archive_write_set_bytes_in_last_block() return ARCHIVE_OK on success,
or ARCHIVE_FATAL.

archive_write_get_bytes_per_block() and
archive_write_get_bytes_in_last_block() return currently configured
block size (-1 indicates the default block size), or ARCHIVE_FATAL.

ERRORS

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

SEE ALSO

tar(1), archive_write_set_options(3), libarchive(3), cpio(5), mtree(5),
tar(5)

illumos February 2, 2012 illumos