--- /dev/null
+=encoding utf8
+
+=head1 NAME
+
+virt-edit - Edit a file in a virtual machine
+
+=head1 SYNOPSIS
+
+ virt-edit [--options] -d domname file [file ...]
+
+ virt-edit [--options] -a disk.img [-a disk.img ...] file [file ...]
+
+ virt-edit [-d domname|-a disk.img] file -e 'expr'
+
+Old-style:
+
+ virt-edit domname file
+
+ virt-edit disk.img [disk.img ...] file
+
+=head1 WARNING
+
+You must I<not> use C<virt-edit> on live virtual machines. If you do
+this, you risk disk corruption in the VM. C<virt-edit> tries to stop
+you from doing this, but doesn't catch all cases.
+
+=head1 DESCRIPTION
+
+C<virt-edit> is a command line tool to edit C<file> where each C<file>
+exists in the named virtual machine (or disk image).
+
+Multiple filenames can be given, in which case they are each edited in
+turn. Each filename must be a full path, starting at the root
+directory (starting with '/').
+
+If you want to just view a file, use L<virt-cat(1)>.
+
+For more complex cases you should look at the L<guestfish(1)> tool
+(see L</USING GUESTFISH> below).
+
+C<virt-edit> cannot be used to create a new file. L<guestfish(1)> can
+do that and much more.
+
+=head1 EXAMPLES
+
+Edit the named files interactively:
+
+ virt-edit -d mydomain /boot/grub/grub.conf
+
+ virt-edit -d mydomain /etc/passwd
+
+For Windows guests, some Windows paths are understood:
+
+ virt-edit -d mywindomain 'c:\autoexec.bat'
+
+If Perl is installed, you can also edit files non-interactively (see
+L</NON-INTERACTIVE EDITING> below).
+To change the init default level to 5:
+
+ virt-edit -d mydomain /etc/inittab -e 's/^id:.*/id:5:initdefault:/'
+
+=head1 OPTIONS
+
+=over 4
+
+=item B<--help>
+
+Display brief help.
+
+=item B<-a> file
+
+=item B<--add> file
+
+Add I<file> which should be a disk image from a virtual machine. If
+the virtual machine has multiple block devices, you must supply all of
+them with separate I<-a> options.
+
+The format of the disk image is auto-detected. To override this and
+force a particular format use the I<--format=..> option.
+
+=item B<-b> extension
+
+=item B<--backup> extension
+
+Create a backup of the original file I<in the guest disk image>.
+The backup has the original filename with C<extension> added.
+
+Usually the first character of C<extension> would be a dot C<.>
+so you would write:
+
+ virt-edit -b .orig [etc]
+
+By default, no backup file is made.
+
+=item B<--connect URI> | B<-c URI>
+
+If using libvirt, connect to the given I<URI>. If omitted, then we
+connect to the default libvirt hypervisor.
+
+If you specify guest block devices directly, then libvirt is not used
+at all.
+
+=item B<-d> guest
+
+=item B<--domain> guest
+
+Add all the disks from the named libvirt guest. Domain UUIDs can be
+used instead of names.
+
+=item B<--echo-keys>
+
+When prompting for keys and passphrases, virt-cat normally turns
+echoing off so you cannot see what you are typing. If you are not
+worried about Tempest attacks and there is no one else in the room you
+can specify this flag to see what you are typing.
+
+=item B<--format> raw|qcow2|...
+
+=item B<--format>
+
+The default for the I<-a> option is to auto-detect the format of the
+disk image. Using this forces the disk format for I<-a> options which
+follow on the command line. Using I<--format> with no argument
+switches back to auto-detection for subsequent I<-a> options.
+
+For example:
+
+ virt-edit --format=raw -a disk.img file
+
+forces raw format (no auto-detection) for C<disk.img>.
+
+ virt-edit --format=raw -a disk.img --format -a another.img file
+
+forces raw format (no auto-detection) for C<disk.img> and reverts to
+auto-detection for C<another.img>.
+
+If you have untrusted raw-format guest disk images, you should use
+this option to specify the disk format. This avoids a possible
+security problem with malicious guests (CVE-2010-3851).
+
+=item B<-e> EXPR
+
+=item B<--expr> EXPR
+
+Instead of launching the external editor, non-interactively
+apply the Perl expression C<EXPR> to each line in the file.
+See L</NON-INTERACTIVE EDITING> below.
+
+Be careful to properly quote the expression to prevent it from
+being altered by the shell.
+
+Note that this option is only available when Perl 5 is installed.
+
+=item B<--keys-from-stdin>
+
+Read key or passphrase parameters from stdin. The default is
+to try to read passphrases from the user by opening C</dev/tty>.
+
+=item B<-v>
+
+=item B<--verbose>
+
+Enable verbose messages for debugging.
+
+=item B<-V>
+
+=item B<--version>
+
+Display version number and exit.
+
+=item B<-x>
+
+Enable tracing of libguestfs API calls.
+
+=back
+
+=head1 OLD-STYLE COMMAND LINE ARGUMENTS
+
+Previous versions of virt-edit allowed you to write either:
+
+ virt-edit disk.img [disk.img ...] file
+
+or
+
+ virt-edit guestname file
+
+whereas in this version you should use I<-a> or I<-d> respectively
+to avoid the confusing case where a disk image might have the same
+name as a guest.
+
+For compatibility the old style is still supported.
+
+=head1 NON-INTERACTIVE EDITING
+
+C<virt-edit> normally calls out to C<$EDITOR> (or vi) so
+the system administrator can interactively edit the file.
+
+There are two ways also to use C<virt-edit> from scripts in order to
+make automated edits to files. (Note that although you I<can> use
+C<virt-edit> like this, it's less error-prone to write scripts
+directly using the libguestfs API and Augeas for configuration file
+editing.)
+
+The first method is to temporarily set C<$EDITOR> to any script or
+program you want to run. The script is invoked as C<$EDITOR tmpfile>
+and it should update C<tmpfile> in place however it likes.
+
+The second method is to use the I<-e> parameter of C<virt-edit> to run
+a short Perl snippet in the style of L<sed(1)>. For example to
+replace all instances of C<foo> with C<bar> in a file:
+
+ virt-edit -d domname filename -e 's/foo/bar/'
+
+The full power of Perl regular expressions can be used (see
+L<perlre(1)>). For example to delete root's password you could do:
+
+ virt-edit -d domname /etc/passwd -e 's/^root:.*?:/root::/'
+
+What really happens is that the snippet is evaluated as a Perl
+expression for each line of the file. The line, including the final
+C<\n>, is passed in C<$_> and the expression should update C<$_> or
+leave it unchanged.
+
+To delete a line, set C<$_> to the empty string. For example, to
+delete the C<apache> user account from the password file you can do:
+
+ virt-edit -d mydomain /etc/passwd -e '$_ = "" if /^apache:/'
+
+To insert a line, prepend or append it to C<$_>. However appending
+lines to the end of the file is rather difficult this way since there
+is no concept of "last line of the file" - your expression just
+doesn't get called again. You might want to use the first method
+(setting C<$EDITOR>) if you want to do this.
+
+The variable C<$lineno> contains the current line number.
+As is traditional, the first line in the file is number C<1>.
+
+The return value from the expression is ignored, but the expression
+may call C<die> in order to abort the whole program, leaving the
+original file untouched.
+
+Remember when matching the end of a line that C<$_> may contain the
+final C<\n>, or (for DOS files) C<\r\n>, or if the file does not end
+with a newline then neither of these. Thus to match or substitute
+some text at the end of a line, use this regular expression:
+
+ /some text(\r?\n)?$/
+
+Alternately, use the perl C<chomp> function, being careful not to
+chomp C<$_> itself (since that would remove all newlines from the
+file):
+
+ my $m = $_; chomp $m; $m =~ /some text$/
+
+=head1 WINDOWS PATHS
+
+C<virt-edit> has a limited ability to understand Windows drive letters
+and paths (eg. C<E:\foo\bar.txt>).
+
+If and only if the guest is running Windows then:
+
+=over 4
+
+=item *
+
+Drive letter prefixes like C<C:> are resolved against the
+Windows Registry to the correct filesystem.
+
+=item *
+
+Any backslash (C<\>) characters in the path are replaced
+with forward slashes so that libguestfs can process it.
+
+=item *
+
+The path is resolved case insensitively to locate the file
+that should be edited.
+
+=back
+
+There are some known shortcomings:
+
+=over 4
+
+=item *
+
+Some NTFS symbolic links may not be followed correctly.
+
+=item *
+
+NTFS junction points that cross filesystems are not followed.
+
+=back
+
+=head1 USING GUESTFISH
+
+L<guestfish(1)> is a more powerful, lower level tool which you can use
+when C<virt-edit> doesn't work.
+
+Using C<virt-edit> is approximately equivalent to doing:
+
+ guestfish --rw -i -d domname edit /file
+
+where C<domname> is the name of the libvirt guest, and C</file> is the
+full path to the file.
+
+The command above uses libguestfs's guest inspection feature and so
+does not work on guests that libguestfs cannot inspect, or on things
+like arbitrary disk images that don't contain guests. To edit a file
+on a disk image directly, use:
+
+ guestfish --rw -a disk.img -m /dev/sda1 edit /file
+
+where C<disk.img> is the disk image, C</dev/sda1> is the filesystem
+within the disk image to edit, and C</file> is the full path to the
+file.
+
+C<virt-edit> cannot create new files. Use the guestfish commands
+C<touch>, C<write> or C<upload> instead:
+
+ guestfish --rw -i -d domname touch /newfile
+
+ guestfish --rw -i -d domname write /newfile "new content"
+
+ guestfish --rw -i -d domname upload localfile /newfile
+
+=head1 ENVIRONMENT VARIABLES
+
+=over 4
+
+=item C<EDITOR>
+
+If set, this string is used as the editor. It may contain arguments,
+eg. C<"emacs -nw">
+
+If not set, C<vi> is used.
+
+=back
+
+=head1 SHELL QUOTING
+
+Libvirt guest names can contain arbitrary characters, some of which
+have meaning to the shell such as C<#> and space. You may need to
+quote or escape these characters on the command line. See the shell
+manual page L<sh(1)> for details.
+
+=head1 SEE ALSO
+
+L<guestfs(3)>,
+L<guestfish(1)>,
+L<virt-cat(1)>,
+L<virt-copy-in(1)>,
+L<virt-tar-in(1)>,
+L<Sys::Guestfs(3)>,
+L<Sys::Guestfs::Lib(3)>,
+L<Sys::Virt(3)>,
+L<http://libguestfs.org/>,
+L<perl(1)>,
+L<perlre(1)>.
+
+=head1 AUTHOR
+
+Richard W.M. Jones L<http://people.redhat.com/~rjones/>
+
+=head1 COPYRIGHT
+
+Copyright (C) 2009-2011 Red Hat Inc.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
git.annexia.org / libguestfs.git / blobdiff