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LIBARCHIVE_CHANGES

Section: C Library Functions (3)
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NAME

libarchive_changes - changes in libarchive interface

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.

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.

Character Set Handling

Libarchive2 assumed that the local platform uses Unicode as the native wchar_t encoding, which is true on Windows modern 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 UTF-8 and libarchive 2 incorrectly assumed that wchar_t strings can be easily converted to UTF-8

Libarchive3 uses the standard iconv library to convert between character sets and is introducing the notion of a ``default character set for the archive'' To support this, archive_entry objects can now be bound to a particular archive when they are created. The automatic character set conversions performed by archive_entry objects when reading and writing filenames, usernames, and other strings will now use an appropriate default character set:

If the archive_entry object is bound to an archive, it will use the default character set for that archive.

The platform default character encoding (as returned by Fn nl_langinfo CHARSET ) will be used if nothing else is specified.

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.

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 int64_t instead of less-portable types such as off_t gid_t uid_t and ino_t

There are a few cases where these changes will affect your source code:

In some cases, libarchive's wider types will introduce the possibility of truncation: for example, on a system with a 16-bit uid_t , you risk having uid 65536 be truncated to uid 0 which can cause serious security problems.
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:
```
#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 ...
}
```

Affected functions:

Fn archive_entry_gid , Fn archive_entry_set_gid
Fn archive_entry_uid , Fn archive_entry_set_uid
Fn archive_entry_ino , Fn archive_entry_set_ino
Fn archive_read_data_block , Fn archive_write_data_block
Fn archive_read_disk_gname , Fn archive_read_disk_uname
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
Fn archive_skip_callback
Fn archive_read_extract_set_skip_file , Fn archive_write_disk_set_skip_file , Fn archive_write_set_skip_file
Fn archive_write_disk_set_group_lookup , Fn archive_write_disk_set_user_lookup

Where these functions or their arguments took or returned gid_t ino_t off_t or uid_t they now take or return int64_t or equivalent.

Deprecated Symbols

Symbols deprecated in libarchive3 will be removed in libarchive4. These symbols, along with their replacements if any, are listed below:

Fn archive_position_compressed , Fn archive_position_uncompressed: Fn archive_filter_bytes
Fn archive_compression: Fn archive_filter_code
Fn archive_compression_name: Fn archive_filter_name
Fn archive_read_finish , Fn archive_write_finish: Fn archive_read_free , Fn archive_write_free
Fn archive_read_open_file , Fn archive_write_open_file: Fn archive_read_open_filename , Fn archive_write_open_filename
Fn archive_read_support_compression_all: Fn archive_read_support_filter_all
Fn archive_read_support_compression_bzip2: Fn archive_read_support_filter_bzip2
Fn archive_read_support_compression_compress: Fn archive_read_support_filter_compress
Fn archive_read_support_compression_gzip: Fn archive_read_support_filter_gzip
Fn archive_read_support_compression_lzip: Fn archive_read_support_filter_lzip
Fn archive_read_support_compression_lzma: Fn archive_read_support_filter_lzma
Fn archive_read_support_compression_none: Fn archive_read_support_filter_none
Fn archive_read_support_compression_program: Fn archive_read_support_filter_program
Fn archive_read_support_compression_program_signature: Fn archive_read_support_filter_program_signature
Fn archive_read_support_compression_rpm: Fn archive_read_support_filter_rpm
Fn archive_read_support_compression_uu: Fn archive_read_support_filter_uu
Fn archive_read_support_compression_xz: Fn archive_read_support_filter_xz
Fn archive_write_set_compression_bzip2: Fn archive_write_add_filter_bzip2
Fn archive_write_set_compression_compress: Fn archive_write_add_filter_compress
Fn archive_write_set_compression_gzip: Fn archive_write_add_filter_gzip
Fn archive_write_set_compression_lzip: Fn archive_write_add_filter_lzip
Fn archive_write_set_compression_lzma: Fn archive_write_add_filter_lzma
Fn archive_write_set_compression_none: Fn archive_write_add_filter_none
Fn archive_write_set_compression_program: Fn archive_write_add_filter_program
Fn archive_write_set_compression_filter: Fn archive_write_add_filter_filter

Removed Symbols

These symbols, listed below along with their replacements if any, were deprecated in libarchive2, and are not part of libarchive3.

Fn archive_api_feature: Fn archive_version_number
Fn archive_api_version: Fn archive_version_number
Fn archive_version: Fn archive_version_string
Fn archive_version_stamp: Fn archive_version_number
Fn archive_read_set_filter_options: Fn archive_read_set_options or Fn archive_read_set_filter_option
Fn archive_read_set_format_options: Fn archive_read_set_options or Fn archive_read_set_format_option
Fn archive_write_set_filter_options: Fn archive_write_set_options or Fn archive_write_set_filter_option
Fn archive_write_set_format_options: Fn archive_write_set_options or Fn archive_write_set_format_option
ARCHIVE_API_FEATURE: ARCHIVE_VERSION_NUMBER
ARCHIVE_API_VERSION: ARCHIVE_VERSION_NUMBER
ARCHIVE_VERSION_STAMP: ARCHIVE_VERSION_NUMBER
ARCHIVE_LIBRARY_VERSION: ARCHIVE_VERSION_STRING
ARCHIVE_COMPRESSION_NONE: ARCHIVE_FILTER_NONE
ARCHIVE_COMPRESSION_GZIP: ARCHIVE_FILTER_GZIP
ARCHIVE_COMPRESSION_BZIP2: ARCHIVE_FILTER_BZIP2
ARCHIVE_COMPRESSION_COMPRESS: ARCHIVE_FILTER_COMPRESS
ARCHIVE_COMPRESSION_PROGRAM: ARCHIVE_FILTER_PROGRAM
ARCHIVE_COMPRESSION_LZMA: ARCHIVE_FILTER_LZMA
ARCHIVE_COMPRESSION_XZ: ARCHIVE_FILTER_XZ
ARCHIVE_COMPRESSION_UU: ARCHIVE_FILTER_UU
ARCHIVE_COMPRESSION_RPM: ARCHIVE_FILTER_RPM
ARCHIVE_COMPRESSION_LZIP: ARCHIVE_FILTER_LZIP
ARCHIVE_BYTES_PER_RECORD: 512
ARCHIVE_DEFAULT_BYTES_PER_BLOCK: 10240

Index

NAME

CHANGES IN LIBARCHIVE 3

Multiple Filters
Character Set Handling
Prototype Changes
Deprecated Symbols
Removed Symbols

SEE ALSO