libarchive/libarchive/libarchive_changes.3

.\" Copyright (c) 2011 Tim Kientzle
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.\" $FreeBSD$
.\"
.Dd December 23, 2011
.Dt LIBARCHIVE_CHANGES 3
.Os
.Sh NAME
.Nd changes in libarchive interface
.\"
.Sh CHANGES IN LIBARCHIVE 3
This page describes user-visible changes in libarchive3, and lists
public functions and other symbols changed, deprecated or removed
in libarchive3, along with their replacements if any.
.Pp
.\"
.Ss Multiple Filters
.\"
Libarchive2 permitted a single (input or output) filter active
on an archive.
Libarchive3 extends this into a variable-length stack.
Where
.Fn archive_write_set_compression_XXX
would replace any existing filter,
.Fn archive_write_add_filter_XXX
extends the write pipeline with another filter.
.\"
.Ss Character Set Handling
.\"
Libarchive2 assumed that the local platform uses
.Tn Unicode
as the native
.Tn wchar_t
encoding, which is true on
.Tn Windows ,
modern
.Tn Linux ,
and a few other systems, but is certainly not universal.
As a result, pax format archives were written incorrectly on some
systems, since pax format requires
.Tn UTF-8
and libarchive 2 incorrectly
assumed that
.Tn wchar_t
strings can be easily converted to
.Tn UTF-8 .
.Pp
Libarchive3 uses the standard iconv library to convert between character
sets and is introducing the notion of a
.Dq default character set for the archive .
To support this,
.Tn archive_entry
objects can now be bound to a particular archive when they are created.
The automatic character set conversions performed by
.Tn archive_entry
objects when reading and writing filenames, usernames, and other strings
will now use an appropriate default character set:
.Pp
If the
.Tn archive_entry
object is bound to an archive, it will use the
default character set for that archive.
.Pp
The platform default character encoding (as returned by
.Fn nl_langinfo CHARSET )
will be used if nothing else is specified.
.Pp
Libarchive3 also introduces charset options to many of the archive
readers and writers to control the character set that will be used for
filenames written in those archives.
When possible, this will be set automatically based on information in
the archive itself.
Combining this with the notion of a default character set for the
archive should allow you to configure libarchive to read archives from
other platforms and have the filenames and other information
transparently converted to the character encoding suitable for your
application.
.\"
.Ss Prototype Changes
.\"
These changes break binary compatibility; libarchive3 has a new shared
library version to reflect these changes.
The library now uses portable wide types such as
.Tn int64_t
instead of less-portable types such as
.Tn off_t ,
.Tn gid_t ,
.Tn uid_t ,
and
.Tn ino_t .
.Pp
There are a few cases where these changes will affect your source code:
.Bl -bullet -width ind
.It
In some cases, libarchive's wider types will introduce the possibility
of truncation: for example, on a system with a 16-bit
.Tn uid_t , you risk having uid
.Li 65536
be truncated to uid
.Li 0 ,
which can cause serious security problems.
.It
Typedef function pointer types will be incompatible.
For example, if you define custom skip callbacks, you may have to use
code similar to the following if you want to support building against
libarchive2 and libarchive3:
.Bd -literal
#if ARCHIVE_VERSION_NUMBER < 3000000
typedef off_t myoff_t;
#else
typedef int64_t myoff_t;
#endif

myoff_t
my_skip_function(struct archive *a, void *v, myoff_t o)
{
    ... implementation ...
}
.Ed
.El
.Pp
Affected functions:
.Pp
.Bl -bullet -compact
.It
.Xo
.Fn archive_entry_gid ,
.Fn archive_entry_set_gid
.Xc
.It
.Xo
.Fn archive_entry_uid ,
.Fn archive_entry_set_uid
.Xc
.It
.Xo
.Fn archive_entry_ino ,
.Fn archive_entry_set_ino
.Xc
.It
.Xo
.Fn archive_read_data_block ,
.Fn archive_write_data_block
.Xc
.It
.Xo
.Fn archive_read_disk_gname ,
.Fn archive_read_disk_uname
.Xc
.It
.Xo
.Fn archive_read_disk_set_gname_lookup ,
.Fn archive_read_disk_set_group_lookup ,
.Fn archive_read_disk_set_uname_lookup ,
.Fn archive_read_disk_set_user_lookup
.Xc
.It
.Fn archive_skip_callback
.It
.Xo
.Fn archive_read_extract_set_skip_file ,
.Fn archive_write_disk_set_skip_file ,
.Fn archive_write_set_skip_file
.Xc
.It
.Xo
.Fn archive_write_disk_set_group_lookup ,
.Fn archive_write_disk_set_user_lookup
.Xc
.El
.Pp
Where these functions or their arguments took or returned
.Tn gid_t ,
.Tn ino_t ,
.Tn off_t ,
or
.Tn uid_t
they now take or return
.Tn int64_t
or equivalent.
.\"
.Ss Deprecated Symbols
.\"
Symbols deprecated in libarchive3 will be removed in libarchive4.
These symbols, along with their replacements if any, are listed below:
.\"
.Bl -tag -width ind
.It Fn archive_position_compressed , Fn archive_position_uncompressed
.Fn archive_filter_bytes
.It Fn archive_compression
.Fn archive_filter_code
.It Fn archive_compression_name
.Fn archive_filter_name
.It Fn archive_read_finish , Fn archive_write_finish
.Fn archive_read_free ,
.Fn archive_write_free
.It Fn archive_read_open_file , Fn archive_write_open_file
.Fn archive_read_open_filename ,
.Fn archive_write_open_filename
.It Fn archive_read_support_compression_all
.\" archive_read_support_compression_* -> archive_read_support_filter_*
.Fn archive_read_support_filter_all
.It Fn archive_read_support_compression_bzip2
.Fn archive_read_support_filter_bzip2
.It Fn archive_read_support_compression_compress
.Fn archive_read_support_filter_compress
.It Fn archive_read_support_compression_gzip
.Fn archive_read_support_filter_gzip
.It Fn archive_read_support_compression_lzip
.Fn archive_read_support_filter_lzip
.It Fn archive_read_support_compression_lzma
.Fn archive_read_support_filter_lzma
.It Fn archive_read_support_compression_none
.Fn archive_read_support_filter_none
.It Fn archive_read_support_compression_program
.Fn archive_read_support_filter_program
.It Fn archive_read_support_compression_program_signature
.Fn archive_read_support_filter_program_signature
.It Fn archive_read_support_compression_rpm
.Fn archive_read_support_filter_rpm
.It Fn archive_read_support_compression_uu
.Fn archive_read_support_filter_uu
.It Fn archive_read_support_compression_xz
.Fn archive_read_support_filter_xz
.\" archive_write_set_compression_* -> archive_write_add_filter_*
.It Fn archive_write_set_compression_bzip2
.Fn archive_write_add_filter_bzip2
.It Fn archive_write_set_compression_compress
.Fn archive_write_add_filter_compress
.It Fn archive_write_set_compression_gzip
.Fn archive_write_add_filter_gzip
.It Fn archive_write_set_compression_lzip
.Fn archive_write_add_filter_lzip
.It Fn archive_write_set_compression_lzma
.Fn archive_write_add_filter_lzma
.It Fn archive_write_set_compression_none
.Fn archive_write_add_filter_none
.It Fn archive_write_set_compression_program
.Fn archive_write_add_filter_program
.It Fn archive_write_set_compression_filter
.Fn archive_write_add_filter_filter
.El
.\"
.Ss Removed Symbols
.\"
These symbols, listed below along with their replacements if any,
were deprecated in libarchive2, and are not part of libarchive3.
.\"
.Bl -tag -width ind
.It Fn archive_api_feature
.Fn archive_version_number
.It Fn archive_api_version
.Fn archive_version_number
.It Fn archive_version
.Fn archive_version_string
.It Fn archive_version_stamp
.Fn archive_version_number
.It Fn archive_read_set_filter_options
.Fn archive_read_set_options
or
.Fn archive_read_set_filter_option
.It Fn archive_read_set_format_options
.Fn archive_read_set_options
or
.Fn archive_read_set_format_option
.It Fn archive_write_set_filter_options
.Fn archive_write_set_options
or
.Fn archive_write_set_filter_option
.It Fn archive_write_set_format_options
.Fn archive_write_set_options
or
.Fn archive_write_set_format_option
.It Dv ARCHIVE_API_FEATURE
.Dv ARCHIVE_VERSION_NUMBER
.It Dv ARCHIVE_API_VERSION
.Dv ARCHIVE_VERSION_NUMBER
.It Dv ARCHIVE_VERSION_STAMP
.Dv ARCHIVE_VERSION_NUMBER
.It Dv ARCHIVE_LIBRARY_VERSION
.Dv ARCHIVE_VERSION_STRING
.\"
.It Dv ARCHIVE_COMPRESSION_NONE
.Dv ARCHIVE_FILTER_NONE
.It Dv ARCHIVE_COMPRESSION_GZIP
.Dv ARCHIVE_FILTER_GZIP
.It Dv ARCHIVE_COMPRESSION_BZIP2
.Dv ARCHIVE_FILTER_BZIP2
.It Dv ARCHIVE_COMPRESSION_COMPRESS
.Dv ARCHIVE_FILTER_COMPRESS
.It Dv ARCHIVE_COMPRESSION_PROGRAM
.Dv ARCHIVE_FILTER_PROGRAM
.It Dv ARCHIVE_COMPRESSION_LZMA
.Dv ARCHIVE_FILTER_LZMA
.It Dv ARCHIVE_COMPRESSION_XZ
.Dv ARCHIVE_FILTER_XZ
.It Dv ARCHIVE_COMPRESSION_UU
.Dv ARCHIVE_FILTER_UU
.It Dv ARCHIVE_COMPRESSION_RPM
.Dv ARCHIVE_FILTER_RPM
.It Dv ARCHIVE_COMPRESSION_LZIP
.Dv ARCHIVE_FILTER_LZIP
.\"
.It Dv ARCHIVE_BYTES_PER_RECORD
.Li 512
.It Dv ARCHIVE_DEFAULT_BYTES_PER_BLOCK
.Li 10240
.El
.Sh SEE ALSO
.Xr libarchive 3 ,
.Xr archive_read 3 ,
.Xr archive_read_filter 3 ,
.Xr archive_read_format 3 ,
.Xr archive_read_set_options 3 ,
.Xr archive_write 3 ,
.Xr archive_write_filter 3 ,
.Xr archive_write_format 3 ,
.Xr archive_write_set_options 3 ,
.Xr archive_util 3