Langue: en

Version: 2010-09-16 (fedora - 01/12/10)

Section: 1 (Commandes utilisateur)


virt-edit - Edit a file in a virtual machine


  virt-edit [--options] domname file
  virt-edit [--options] disk.img [disk.img ...] file
  virt-edit [domname|disk.img] file -e 'expr'


You must not use "virt-edit" on live virtual machines. If you do this, you risk disk corruption in the VM. "virt-edit" tries to stop you from doing this, but doesn't catch all cases.


"virt-edit" is a command line tool to edit "file" where "file" exists in the named virtual machine (or disk image).

If you want to just view a file, use virt-cat(1). For more complex cases you should look at the guestfish(1) tool.


Edit the named files interactively:
  virt-edit mydomain /boot/grub/grub.conf
  virt-edit mydomain /etc/passwd

You can also edit files non-interactively (see ``NON-INTERACTIVE EDITING'' below). To change the init default level to 5:

  virt-edit mydomain /etc/inittab -e 's/^id:.*/id:5:initdefault:/'


Display brief help.
Display version number and exit.
--backup extension | -b extension
Create a backup of the original file in the guest disk image. The backup has the original filename with "extension" added.

Usually the first character of "extension" would be a dot "." so you would write:

  virt-edit -b .orig [etc]

By default, no backup file is made.

--connect URI | -c URI
If using libvirt, connect to the given 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.

--expr EXPR | -e EXPR
Instead of launching the external editor, non-interactively apply the Perl expression "EXPR" to each line in the file. See ``NON-INTERACTIVE EDITING'' below.

Be careful to properly quote the expression to prevent it from being altered by the shell.


"virt-edit" normally calls out to $EDITOR (or vi) so the system administrator can interactively edit the file.

There are two ways also to use "virt-edit" from scripts in order to make automated edits to files. (Note that although you can use "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 $EDITOR to any script or program you want to run. The script is invoked as "$EDITOR tmpfile" and it should update "tmpfile" in place however it likes.

The second method is to use the "-e" parameter of "virt-edit" to run a short Perl snippet in the style of sed(1). For example to replace all instances of "foo" with "bar" in a file:

  virt-edit domname filename -e 's/foo/bar/'

The full power of Perl regular expressions can be used (see perlre(1)). For example to delete root's password you could do:

  virt-edit 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 "\n", is passed in $_ and the expression should update $_ or leave it unchanged.

To delete a line, set $_ to the empty string. For example, to delete the "apache" user account from the password file you can do:

  virt-edit mydomain /etc/passwd -e '$_ = "" if /^apache:/'

To insert a line, prepend or append it to $_. 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 $EDITOR) if you want to do this.

The variable $lineno contains the current line number. As is traditional, the first line in the file is number 1.

The return value from the expression is ignored, but the expression may call "die" in order to abort the whole program, leaving the original file untouched.

Remember when matching the end of a line that $_ may contain the final "\n", or (for DOS files) "\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 "chomp" function, being careful not to chomp $_ itself (since that would remove all newlines from the file):

  my $m = $_; chomp $m; $m =~ /some text$/


If set, this string is used as the editor. It may contain arguments, eg. "emacs -nw"

If not set, "vi" is used.


guestfs(3), guestfish(1), virt-cat(1), Sys::Guestfs(3), Sys::Guestfs::Lib(3), Sys::Virt(3), <>, perl(1), perlre(1).


Richard W.M. Jones <> Copyright (C) 2009-2010 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.