archive.pl -- Access several archive formats

This library uses libarchive to access a variety of archive formats. The following example lists the entries in an archive:

list_archive(File) :-
      archive_open(File, Archive, []),
      repeat,
         (   archive_next_header(Archive, Path)
         ->  format('~w~n', [Path]),
             fail
         ;   !,
             archive_close(Archive)
         ).

See also: - http://code.google.com/p/libarchive/

archive_open(+Data, +Mode, -Archive, +Options) is det

Open the archive in Data and unify Archive with a handle to the opened archive. Data is either a file or a stream that contains a valid archive. Details are controlled by Options. Typically, the option close_parent(true) is used to close stream if the archive is closed using archive_close/1. For other options, the defaults are typically fine. The option format(raw) must be used to process compressed streams that do not contain explicit entries (e.g., gzip'ed data) unambibuously. The raw format creates a pseudo archive holding a single member named data.

close_parent(+Boolean): If this option is true (default false), Stream is closed if archive_close/1 is called on Archive.
compression(+Compression): Synomym for filter(Compression). Deprecated.
filter(+Filter): Support the indicated filter. This option may be used multiple times to support multiple filters. In read mode, If no filter options are provided, all is assumed. In write mode, none is assumed. Supported values are all, bzip2, compress, gzip, grzip, lrzip, lzip, lzma, lzop, none, rpm, uu and xz. The value all is default for read, none for write.
format(+Format): Support the indicated format. This option may be used multiple times to support multiple formats in read mode. In write mode, you must supply a single format. If no format options are provided, all is assumed for read mode. Note that all does not include raw. To open both archive and non-archive files, both format(all) and format(raw) must be specified. Supported values are: all, 7zip, ar, cab, cpio, empty, gnutar, iso9660, lha, mtree, rar, raw, tar, xar and zip. The value all is default for read.

Note that the actually supported compression types and formats may vary depending on the version and installation options of the underlying libarchive library. This predicate raises a domain error if the (explicitly) requested format is not supported.

Errors: - domain_error(filter, Filter) if the requested filter is not supported.; - domain_error(format, Format) if the requested format type is not supported.

archive_close(+Archive) is det

Close the archive. If close_parent(true) is specified, the underlying stream is closed too. If there is an entry opened with archive_open_entry/2, actually closing the archive is delayed until the stream associated with the entry is closed. This can be used to open a stream to an archive entry without having to worry about closing the archive:

archive_open_named(ArchiveFile, EntryName, Stream) :-
    archive_open(ArchiveFile, Handle, []),
    archive_next_header(Handle, Name),
    archive_open_entry(Handle, Stream),
    archive_close(Archive).

archive_property(+Handle, ?Property) is nondet

True when Property is a property of the archive Handle. Defined properties are:

filters(List): True when the indicated filters are applied before reaching the archive format.

archive_next_header(+Handle, -Name) is semidet

Forward to the next entry of the archive for which Name unifies with the pathname of the entry. Fails silently if the name of the archive is reached before success. Name is typically specified if a single entry must be accessed and unbound otherwise. The following example opens a Prolog stream to a given archive entry. Note that Stream must be closed using close/1 and the archive must be closed using archive_close/1 after the data has been used. See also setup_call_cleanup/3.

open_archive_entry(ArchiveFile, Entry, Stream) :-
    open(ArchiveFile, read, In, [type(binary)]),
    archive_open(In, Archive, [close_parent(true)]),
    archive_next_header(Archive, Entry),
    archive_open_entry(Archive, Stream).

Errors: - permission_error(next_header, archive, Handle) if a previously opened entry is not closed.

archive_open_entry(+Archive, -Stream) is det

Open the current entry as a stream. Stream must be closed. If the stream is not closed before the next call to archive_next_header/2, a permission error is raised.

archive_set_header_property(+Archive, +Property)

Set Property of the current header. Write-mode only. Defined properties are:

filetype(-Type): Type is one of file, link, socket, character_device, block_device, directory or fifo. It appears that this library can also return other values. These are returned as an integer.
mtime(-Time): True when entry was last modified at time.
size(-Bytes): True when entry is Bytes long.
link_target(-Target): Target for a link. Currently only supported for symbolic links.

archive_header_property(+Archive, ?Property)

True when Property is a property of the current header. Defined properties are:

filetype(-Type): Type is one of file, link, socket, character_device, block_device, directory or fifo. It appears that this library can also return other values. These are returned as an integer.
mtime(-Time): True when entry was last modified at time.
size(-Bytes): True when entry is Bytes long.
link_target(-Target): Target for a link. Currently only supported for symbolic links.
format(-Format): Provides the name of the archive format applicable to the current entry. The returned value is the lowercase version of the output of archive_format_name().
permissions(-Integer): True when entry has the indicated permission mask.

archive_extract(+ArchiveFile, +Dir, +Options)

Extract files from the given archive into Dir. Supported options:

remove_prefix(+Prefix): Strip Prefix from all entries before extracting
exclude(+ListOfPatterns): Ignore members that match one of the given patterns. Patterns are handed to wildcard_match/2.

Errors: - existence_error(directory, Dir) if Dir does not exist or is not a directory.; - domain_error(path_prefix(Prefix), Path) if a path in the archive does not start with Prefix
To be done: - Add options

set_permissions(+Perm:integer, +Target:atom)[private]

Restore the permissions. Currently only restores the executable permission.

archive_entries(+Archive, -Paths) is det

True when Paths is a list of pathnames appearing in Archive.

archive_data_stream(+Archive, -DataStream, +Options) is nondet

True when DataStream is a stream to a data object inside Archive. This predicate transparently unpacks data inside possibly nested archives, e.g., a tar file inside a zip file. It applies the appropriate decompression filters and thus ensures that Prolog reads the plain data from DataStream. DataStream must be closed after the content has been processed. Backtracking opens the next member of the (nested) archive. This predicate processes the following options:

meta_data(-Data:list(dict))

If provided, Data is unified with a list of filters applied to the (nested) archive to open the current DataStream. The first element describes the outermost archive. Each Data dict contains the header properties (archive_header_property/2) as well as the keys:

filters(Filters:list(atom)): Filter list as obtained from archive_property/2
name(Atom): Name of the entry.

Non-archive files are handled as pseudo-archives that hold a single stream. This is implemented by using archive_open/3 with the options [format(all),format(raw)].

archive_create(+OutputFile, +InputFiles, +Options) is det

Convenience predicate to create an archive in OutputFile with data from a list of InputFiles and the given Options.

Besides options supported by archive_open/4, the following options are supported:

directory(+Directory): Changes the directory before adding input files. If this is specified, paths of input files must be relative to Directory and archived files will not have Directory as leading path. This is to simulate -C option of the tar program.
format(+Format): Write mode supports the following formats: `7zip, cpio,gnutar, iso9660, xar and zip`. Note that a particular installation may support only a subset of these, depending on the configuration of libarchive.

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

archive_open(Arg1, Arg2, Arg3)