Refactor the read_compression_program to add two new abilities:
* Public API: You can now include a signature string when you
register a program; the program will run only on input that
matches the signature string.
* Internal API: You can use the init() function to instantiate
an external program as part of a filter pipeline. This
can be used for graceful fallback (if zlib is unavailable, use
external gzip instead) and to use external programs with
bidders that are more sophisticated than a static signature check.
from libarchive.googlecode.com: Add a new "archive_read_disk" API
that provides the important service of reading metadata from the
disk. In particular, this will make it possible to remove all
knowledge of extended attributes, ACLs, etc, from clients such
as bsdtar and bsdcpio.
Closely related, this API also provides pluggable uid->uname
and gid->gname lookup and caching services similar to
the uname->uid and gname->gid services provided by archive_write_disk.
Remember this is also required for correct ACL management.
Documentation is still pending...
* Wrap long declarations to fit 80 chars
* #undef macros that shouldn't be exported
* Organize the version-dependent conditionals a
bit more consistently
Speculative:
* libarchive 3.0 will (eventually) use int64_t
instead of off_t. This is an attempt to avoid
some the headaches caused by Linux LFS. (I'll
still have to do ugly things for the struct stat
references in archive_entry.h, of course.)
is present for FreeBSD. If you "make distfile" on FreeBSD, you will
soon have a tar.gz file suitable for deploying to other systems
(complete with the expected "configure" script, etc). This latter
relies (at least for now) on the GNU auto??? tools. (I like autoconf
okay, but someday I hope to write a custom Makefile.in and dispense
with automake, which is somewhat odious.)
As part of this, I've cleaned up some of the conditional
compilation options, added make-foo to construct archive.h dynamically
(it now contains some version constants), and added some useful
informational files.
archive_version: Returns a text string, e.g., "libarchive 1.00.000"
archive_api_version: Returns the SHLIB major version
archive_api_feature: Returns a feature number useful for answering
questions such as "Is this recent enough to do XXX?"
The last two also have macros defined in archive.h, so you can compare
the compile-time and run-time environments. (In particular, you can
compare ARCHIVE_API_VERSION to archive_api_version() to detect library
version mismatches.)
With these in hand, it will soon be time to turn on the
shared-library version of libarchive... stay tuned.
* Rename some variables/functions/etc to try to make things clearer.
* Add separate flags to control fflag/acl restore
* Collect metadata restore into a single function for clarity
* Propagate errors in metadata restore back out to the client
* Fix some places where errors were being returned when they
shouldn't and vice-versa
* Modes are now always restored; ARCHIVE_EXTRACT_PERM just controls
whether or not umask is obeyed.
* Restore suid/sgid bits only if user/group matches archive
* Cache the last stat results to try to reduce the number of stat calls
This change also pointed out one API deficiency: the
archive_read_data_into_XXX functions were originally defined to return
the total bytes read. This is, of course, ambiguous when dealing with
non-contiguous files. Change it to just return a status value.
* New read_data_block is both sparse-file aware and uses zero-copy semantics
* Push read_data_block down into specific formats (opens door to
various encoded entry bodies, such as zip or gtar -S)
* Reimplement read_data, read_data_skip, read_data_into_fd in terms
of new read_data_block.
* Update documentation
It's unfortunate that I couldn't just call the new interface
archive_read_data, but didn't want to upset the API that much.
with 'star' ACL handling, though there's still a
bit more work needed in this area.
Added 'write_open_fd' and 'read_open_fd' to simplify, e.g.,
tar's u and r modes. Eliminated old 'write_open_file_position'
as a bad idea. (It required closing/reopening files to
do updates, which led to unpleasant implications.)
Various other minor fixes, API tweaks, etc.
* Disabled shared-library building, as some API breakage is
still likely. (I didn't realize it was turned on by default.) If
you have an existing /usr/lib/libarchive.so.2, I recommend deleting it.
* Pax interchange format now correctly stores and reads UTF8
for extended attributes. In particular, pax format can portably
handle arbitrarily long pathnames containing arbitrary characters.
* Library compiles cleanly at -O2, -O3, and WARNS=6 on all
FreeBSD-CURRENT platforms.
* Minor portability improvements inspired by Juergen Lock
and Greg Lewis. (Less reliance on stdint.h, isolating of
various portability-challenged constructs.)
* archive_entry transparently converts multi-byte <-> wide character
strings, allowing clients and format handlers to deal with either
one, as appropriate.
* Support for reading 'L' and 'K' entries in standard tar archives
for star compatibility.
* Recognize (but don't yet handle) ACL entries from Solaris tar.
* Pushed format-specific data for format readers down into
format-specific storage and out of library-global storage. This
should make it easier to maintain individual formats without mucking
with the core library management.
* Documentation updates to track the above changes.
* Updates to tar.5 to correct a few mistakes and add some additional
information about GNU tar and Solaris tar formats.
Notes:
* The basic 'tar' reader is getting more general; there's not much
point in keeping the 'gnutar' reader separate. Merging the two
would lose a bunch of duplicate code.
* The libc ACL support is looking increasingly inadequate for my needs
here. I might need to assemble some fairly significant code for
parsing and building ACLs. <sigh>
Portability: Thanks to Juergen Lock, libarchive now compiles cleanly
on Linux. Along the way, I cleaned up a lot of error return codes and
reorganized some code to simplify conditional compilation of certain
sections.
Bug fixes:
* pax format now actually stores filenames that are 101-154
characters long.
* pax format now allows newline characters in extended attributes
(this fixes a long-standing bug in ACL handling)
* mtime/atime are now restored for directories
* directory list is now sorted prior to fix-up to permit
correct restore of non-writable dir heirarchies
What it is:
A library for reading and writing various streaming archive
formats, especially tar and cpio. Being a library, it should
be easy to incorporate into pkg_* tools, sysinstall, and any
other place that needs to read or write such archives.
Features:
* Full automatic detection of both compression and archive format.
* Extensible internal architecture to make it easy to add new formats.
* Support for "pax interchange format," a new POSIX-standard tar format
that eliminates essentially all of the restrictions of historic formats.
* BSD license
Thanks to: jkh for pushing me to start this work, gordon for
encouraging me to commit it, bde for answering endless style
questions, and many others for feedback and encouragement.
Status: Pretty good overall, though there are still a few rough edges and
the library could always use more testing. Feedback eagerly solicited.
