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File Date Author Commit
avfscoda 2001-05-31 mszeredi mszeredi [1c4d02] avfscoda security and other fixes
bzlib 2001-05-18 mszeredi mszeredi [a9c6ac] indexing of bzip2 files
extfs 2001-05-04 mszeredi mszeredi [c5a162] archive support started
include 2001-05-25 mszeredi mszeredi [47ac81] cleanups and bugfixes
lib 2001-05-16 mszeredi mszeredi [6e7fdb] bzlib added
libneon 2001-05-04 mszeredi mszeredi [c5a162] archive support started
macros 2001-03-13 mszeredi mszeredi [14ac10] libneon is bundled + total reorganization of di...
modules 2001-05-29 mszeredi mszeredi [0e328a] rsh improvements
patch 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
preload 2001-05-25 mszeredi mszeredi [7b7412] install fixes
scripts 2001-05-28 mszeredi mszeredi [b0fcc1] install fix
spec 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
src 2001-05-25 mszeredi mszeredi [47ac81] cleanups and bugfixes
test 2001-05-24 mszeredi mszeredi [85dfd3] minor bugfixes
zlib 2001-05-14 mszeredi mszeredi [246bda] ugz and zfile fixes
.cvsignore 2001-05-04 mszeredi mszeredi [c5a162] archive support started
COPYING 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
COPYING.LIB 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
FORMAT 2001-05-24 mszeredi mszeredi [57ba53] documentation changes
INSTALL.avfscoda 2001-05-25 mszeredi mszeredi [7b7412] install fixes
INSTALL.preload 2001-05-25 mszeredi mszeredi [7b7412] install fixes
Makefile 2001-05-16 mszeredi mszeredi [6e7fdb] bzlib added
NEWS 2001-05-24 mszeredi mszeredi [57ba53] documentation changes
README 2001-05-29 mszeredi mszeredi [0e328a] rsh improvements
TODO 2001-05-24 mszeredi mszeredi [57ba53] documentation changes
acconfig.h 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
aclocal.m4 2001-03-19 mszeredi mszeredi [0de4a6] build fixes
config.guess 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
config.h.in 2001-05-25 mszeredi mszeredi [7b7412] install fixes
config.sub 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
configure 2001-05-25 mszeredi mszeredi [7b7412] install fixes
configure.in 2001-05-25 mszeredi mszeredi [7b7412] install fixes
install-sh 2001-03-01 mszeredi mszeredi [30ed08] Initial revision
mkconf 2001-03-13 mszeredi mszeredi [14ac10] libneon is bundled + total reorganization of di...
mkinstalldirs 2001-03-01 mszeredi mszeredi [30ed08] Initial revision

Read Me

What Is AVFS
------------

AVFS is a system, which enables all programs to look inside archived
or compressed files, or access remote files without recompiling the
programs or changing the kernel.

At the moment it supports floppies, tar and gzip files, zip, bzip2, ar
and rar files, ftp sessions, http, webdav, rsh/rcp, ssh/scp. Quite a
few other handlers are implemented with the Midnight Commander's
external FS.

AVFS is (C) under the GNU GPL (see the file COPYING). The shared
library supporting AVFS with LD_PRELOAD is (C) unred the GNU LGPL (see
the file COPYING.LIB).

AVFS comes with ABSOLUTELY NO WARRANTY, for details see the file COPYING. 

Where Is The Latest Version
---------------------------

Check out the page

  http://www.inf.bme.hu/~mszeredi/avfs/

or

  http://sourceforge.net/projects/avf

Forms of AVFS
-------------

AVFS can now be installed in two different ways. These are:

 - Avfscoda 
        This method in theory works on any Linux system which has the
        'coda' filesystem compiled in the kernel or as a kernel module.

        In practice it works best with glibc-6.1 or higher, and it has
        been tested on 2.2.X and 2.4.X kernels.

 - Preload
        Currently this works on solaris systems. There are problems
        making the preload method work for GLIBC version 6.1 or
        higher, so systems using GLIBC are not supported.

Using AVFS is very similar in both cases. Differences will be indicated.

The installation method is different. For installation instructions
see the files 'INSTALL.preload' and 'INSTALL.avfscoda' respectively.

Using AVFS
----------

It is quite simple, you just do everything with the virtual files, as
you would do with real files. Here are some examples:

Listing a tar archive:

  ls -l avfs-0.9.1.tgz#/
  ls -l avfs-0.9.1.tgz#/avfs-0.9.1/

Obtaining information about avfs itself:

  cat /#avfsstat/copyright      - prints copyright information and version
  cat /#avfsstat/modules        - lists available handlers
  cat /#avfsstat/version        - prints version information

'cd' into an archive:
  (For the 'preload' method the shell itself must be started with
   avfs)

  cd avfs-0.9.1.tgz#/
  less avfs-0.9.1/README

Some more examples: (these are all shell commands, but of course you
could use any program: file manager, browser, editor, etc.)

Unpacking an archive:

  cp -a tarfile.tgz#/dir .
  cp -a zipfile.zip#/* .

  (For the 'preload' method, using '*' means that the shell must be
   started with AVFS)

Creating an archive:

  mkdir tarfile.tgz#+  
  cp -a dir tarfile.tgz#+/

  Note: The efficiency of this method is not yet the same as the
  'normal' archive creation method, but it should not be more than 2
  times slower.

NOTES:

2) ('preload' only) Input and output redirection to/from virtual files
   does not work. This is not a problem with the 'avfscoda' method.

   E.g. you can't do
           patch -p0 < patchfile.gz#

   only
           cat patchfile.gz# | patch -p0


If something doesn't work, then check the section 'Common Problems'.


Format of an AVFS Path
----------------------

(For a full explanation of the format see the file FORMAT)

As you've seen, the '#' magic character makes a virtual file or
directory from an ordinary file. Actually this is just a shorthand for
the full specification of an AVFS path:

  'tarfile.tgz#' is the same as 'tarfile.tgz#ugz#utar'

Note, the short version will only work if the file-extension is
recognized (most are), but you can always tell exactly what should be
done with the file by using the second method.

There are handlers which do not have a "base" file. The following
handlers are like this: floppy, ftp, rsh, ssh, http, dav, avfsstat,
volatile, rpms.

Examples

  /#floppy:a                                 - a: drive
  /#a                                        - a: drive (alias for /#floppy:a)
  /#rsh:otherhost/foo/bar                    - /foo/bar on 'otherhost'
  /#ssh:user@host/dir                        - /dir on 'host', login as 'user'
  /#ftp:ftp.funet.fi/pub/Linux               - anonymous ftp 
  /#ftp:user@host.domain.org/home/xyz/file   - ftp with username 'user'
  /#ftp_ctl:user@host.domain.org/password    - write the password to this file
                                        (ftppass is a nice utility for this)
  /#http:www.inf.bme.hu|~mszeredi|avfs|      - homepage of AVFS
  /#http:ftp:||ftp.funet.fi|pub|Linux        - use HTTP to get an ftp URL
                                        (useful if you use a HTTP-only proxy)

The environment variable 'http_proxy' is used to set the default value
of the proxy server. You can also set it's value by writing to the file

   /#avfsstat/http_proxy


The following "handelers" are available now:

  name of handler    type of operation      notes
  ---------------    -----------------      -----
  #ugz               gunzip                 builtin,
  #ugzip             gunzip                 uses gzip
  #uz                uncompress             uses gzip
  #gz                gzip                   uses gzip
  #ubz2              bunzip2                builtin
  #ubzip2            bunzip2                uses bzip2
  #bz2               bzip2                  uses bzip2
  #utar              untar                  builtin
  #uzip              unzip                  builtin
  #urar              unrar                  builtin list + uses rar to extract
  #uar               un-ar                  builtin
  #avfsstat          meta information       builtin
  #floppy            floppy                 uses mtools (mdir, mcopy, ...)
  #a                 first floppy drive     alias for #floppy:a
  #rsh               rsh/rcp                only works if rsh needs no password
  #ssh               ssh/scp                only works if ssh needs no password
  #ftp               ftp                    builtin
  #ftp_ctl           control ftp sessions   
  #dav               webdav                 builtin
  #dav_ctl           control dav sessions   
  #volatile          'memory fs'            mainly for testing
  #local             local filesysem        only for internal use

The following handlers are available through Midnight Commanders
'extfs'. These were not written by me, and could contain security
holes. Nonetheless some of them are quite useful.  For documentation
on these, see the files in /usr/lib/avfs/extfs.

  name of handler    type of operation
  ---------------    -----------------
  #uzoo              zoo archives
  #ulha              lha archives
  #ucpio             cpio archives
  #rpm               rpm packages
  #deb               debian packages
  #lslR              directory tree listings
  #ftplist           ?
  #hp48              ?
  #patchfs           browse patch files
  #mailfs            ? 
  #rpms              List of installed rpms
  #trpm              Useful inside #rpms


Writing new modules
-------------------

You want to write a handler module for XY? Great! Please contact me,
and I can give you some advice regarding this.

Credits
-------

David Hanak (dhanak@inf.bme.hu) has contibuted the "rar" and the
"archive" modules, and lots of ideas to AVFS.

The VFS in Midnight Commander, written by Jakub Jelinek and Miguel de
Icaza <miguel@nuclecu.unam.mx>, has greatly helped me write this
library, and will probably continue to do so in the future.

Pavel Machek, who is the current maintainer of Midnight VFS, and who
has contributed lots of ideas and the alien module (which
unfortunately I did not have time to get into shape) to AVFS.  The
'avfscoda' solution grew out of Pavels 'podfuk'. Most of it has been
changed, but the original idea is from Pavel.

Justin Mason <jm-avfs@jmason.org> contributed the dav module.

Koblinger Egmont <egmont@fazekas.hu> has written the "recursive
profile" scripts, set up the mailing list, and also sent me many good
ideas.

The zip and gzip file handler is based on the zlib compression and
decompression library, written by Jean-loup Gailly and Mark Adler.

The bzip2 handler uses the libbzip2 library written by Julian R
Seward.

The tar file handler is based on the GNU tar source, originally
written by John Gilmore.

People, who sent me ideas or bug-reports:
  Jan Niehusmann <jan@gondor.com>
  Demon of the Known Universe <psycho@dodds.net>
  Duncan Pierce <cmrdrp@soc.staffs.ac.uk>
  Scott F. Johnston <scott@fleetingimage.com>
  Larry Riedel <larry@riedel.org>

The Future
----------

I hope AVFS will grow up to be a standard virtual file library, for which
people can write handler modules (or plugins, if you like) for whatever
they want. 

If you thing AVFS is a good idea, and you have any comments or suggestions,
please send me an email about them.

Have fun,

Miklos Szeredi <mszeredi@inf.bme.hu>