xref: /external/e2fsprogs/ext2ed

ext2ed - The extended-2 filesystem editor, version e2fsprogs


This version of ext2ed has been modified and updated by Theodore Ts'o
for inclusion with the e2fsprogs package.  It now builds with modern
ncurses and I've fixed various small bugs, particular in the redrawing
and resizing functions.

It is currently not built by default -- the top-level e2fsprogs
Makefile doesn't recurse into this directory.  This is because ext2ed
has a number of VERY SERIOUS shortcomings:

1)  It doesn't work on filesystems bigger than 2GB

2)  It assumes that all's the world an Intel, and assumes that
	everything is in Intel (little-endian) byte order.

Fixing either of these problems would be non-trivial, and so I at this
point DO NOT RECOMMEND that distributions try to include this program,
even as modified and updated in e2fsprogs.  This especially goes for
Debian, where the Debian maintainer for e2fsprogs has a history of
making authorized changes to e2fsprogs to include programs that aren't
supported, and then starts bugging me with bug reports.  YES I KNOW.
THIS PROGRAM HAS HORRIBLE SHORTCOMINGS.  IT IS INCLUDED HERE ONLY
BECAUSE IT'S A CONVENIENT WAY FOR (FOR E2FSPROGS DEVELOPERS ON INTEL
MACHINES) TO GENERATE TEST CASES BY SELECTIVELY CORRUPTING
FILESYSTEMS.  I WILL NOT SUPPORT THIS PROGRAM FOR USE BY GENERAL USERS
SO PLEASE DO NOT INCLUDE IT IN A DISTRIBUTION.

I have currently disabled the use of GNU Readline in this program,
because readline and ncurses really don't play well together at all.
Readline assumes that it can write arbitrary text to the screen
(especially when it tries to print out a completion list), which just
doesn't work with ncurses.  Fixing this so they would work together
would require wholesale changes to readline.   

				Theodore Ts'o
				tytso (a] MIT.EDU
				May 12, 2001

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ext2ed - The extended-2 filesystem editor, version 0.2
------------------------------------------------------

This is version 0.2 of ext2ed - The extended-2 filesystem editor.

Modifications on Apr 5 2001
This is minor bug fixes to ext2ed, as of April 2001.
It supports modern ext2 version that has file type in directory structure
and fixes the missunderstanding between ncurses and
readline.

I first applied patches from Redhat except the one for readline that 
rewrote a readline behavior.

Globals diffs between version 0.1 and 0.2 is stored in file :
	diff-ext2ed.1.2

Christian Bac <Christian.Bac (a] nt-evry.fr>

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Documentation
-------------

ext2ed's documentation consists of three documents:

1.	The user's guide.
2.	Technical overview of the ext2 filesystem.
3.	The EXT2ED design and implementation document.

Those documents are available in the doc directory, in linuxdoc-sgml and
postscript formats.

The documentation is also available online at:

http://tochnapc2.technion.ac.il

under the ext2ed section.

Installation
------------

ext2ed requires the kernel sources and the readline and ncurses packages.
Please edit the makefile if you are using an "old" version of ncurses (See the
details below) or if gcc can't find the various header files and libraries.

To install, simply issue a 'make' command to compile and a 'make install'
command to install. I have also included an already compiled linux a.out
binary.

ext2ed and ncurses
------------------

ext2ed uses the ncurses library for terminal output. It is very important
that ncurses will be properly installed on your system:

1.	Old versions of ncurses (around 1.8.5) need the OLD_NCURSES compile
	time option in EXT2ED.

	At least from 1.9.2c, this flag should not be used. I would recommend
	upgrading the ncurses library to the newer versions.

2.	ncurses uses its own terminfo database rather then the termcap file.
	It is important that the terminfo database will be found by ncurses.
	If this is not the case, you will see on startup some lines which
	refer to /etc/termcap. This will mean that there is a problem with
	the terminfo database.

3.	Newer versions of ncurses (and the 1.3 series of the kernel) describe
	the linux console in the entry 'linux' and not 'console', as it was
	before. If you run ext2ed in the linux console, you should either
	set your TERM environment variable to 'linux' or link
	l/linux to c/console in the terminfo database.

4.	The percompiled binary was linked with ncurses 1.9.4 and will search
	for the terminfo database on /usr/local/lib/terminfo. If you are
	using it, and your 1.9.4 compatible terminfo database is not on the
	directory above, use the TERMINFO environment variable to specify
	an alternate location.

Running ext2ed
--------------

For those of you who don't like reading lengthy articles, here are a few
basic guidelines:

1.	Don't use ext2ed to change a mounted filesystem !

	Using ext2ed in read-only mode on a mounted filesystem can be allowed
	by using the configuration file option 'AllowMountedRead on'. However,
	note that the displayed data will be unreliable.

2.	ext2ed currently can't handle filesystems bigger than 2 GB. I am
	sorry for the inconvenience. This will hopefully be fixed in future
	releases.

3. 	Before running ext2ed, edit the configuration file
	/var/lib/ext2ed/ext2ed.conf to suit your needs. The various
	configuration options are documented there.

4.	Use the 'setdevice' command to open an ext2 filesystem.
	e.g. 'setdevice /dev/hda1'.

5.	If the filesystem is an ext2 filesystem and ext2ed fails to
	autodetect this, use the 'ForceExt2 on' configuration file option.

6.	The filesystem will always be opened in read-only mode. Feel free to
	experiment, but take care with the 'enablewrite' command.

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Feel free to send me feedback with anything regarding to ext2ed.

Enjoy,

Gadi Oxman <tgud (a] tochnapc2.technion.ac.il>
Haifa, August 23 1995