- See also
- https://github.com/libarchive/libarchive/
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)
).
Here is another example which counts the files in the archive and
prints file type information. It uses archive_foldl/4,
a higher level predicate:
print_entry(Path, Handle, Cnt0, Cnt1) :-
archive_header_property(Handle, filetype(Type)),
format('File ~w is of type ~w~n', [Path, Type]),
Cnt1 is Cnt0 + 1.
list_archive(File) :-
archive_foldl(print_entry, File, 0, FileCount),
format('We have ~w files', [FileCount]).
- [det]archive_open(+Data,
-Archive, +Options)
- Wrapper around archive_open/4
that opens the archive in read mode.
- [det]archive_open(+Data,
+Mode, -Archive, +Options)
- 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 and mtree.
To open both archive and non-archive files, both format(all)
and
format(raw) and/or format(mtree) 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.
- [det]archive_close(+Archive)
- 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).
- [nondet]archive_property(+Handle,
?Property)
- 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.
- [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.
- [det]archive_open_entry(+Archive,
-Stream)
- 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.
- 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.
- 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.
- Extract files from the given archive into Dir. Supported
options:
- remove_prefix(+Prefix)
- Strip Prefix from all entries before extracting. If Prefix
is a list, then each prefix is tried in order, succeding at the first
one that matches. If no prefixes match, an error is reported. If Prefix
is an atom, then that prefix is removed.
- exclude(+ListOfPatterns)
- Ignore members that match one of the given patterns. Patterns are handed
to wildcard_match/2.
- include(+ListOfPatterns)
- Include members that match one of the given patterns. Patterns are
handed to wildcard_match/2. The
exclude
options takes preference if a member matches both the include
and the exclude option.
- 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
- [det]archive_entries(+Archive,
-Paths)
- True when Paths is a list of pathnames appearing in Archive.
- [nondet]archive_data_stream(+Archive,
-DataStream, +Options)
- 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)].
- [det]archive_create(+OutputFile,
+InputFiles, +Options)
- 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.
- archive_foldl(:Goal,
+Archive, +State0, -State)
- Operates like foldl/4 but for the entries
in the archive. For each member of the archive, Goal called
as `call(:Goal, +Path, +Handle, +S0, -S1). Here, S0
is current state of the accumulator (starting with State0)
and S1 is the next state of the accumulator, producing State
after the last member of the archive.
| Archive | File name or stream to be given to
archive_open/[3,4]. |
- See also
- archive_header_property/2, archive_open/4.