virt-edit(1)

📦
version 1.57.3 · 15 versions
, in centos-stream 10

✨ NAME ✨

Okay so bestie, meet virt-edit — the main character of virt-edit(1) from the Virtualization Support manual, and it literally edits a file in a virtual machine. Slay.

🦋 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

💀 WARNING 💀

Using virt-edit on live virtual machines, or concurrently with other disk editing tools, can be dangerous, potentially causing disk corruption. The virtual machine must be shut down before you use this command, and disk images must not be edited concurrently. No cap, this is the serious part. 🫶

🌸 DESCRIPTION 🌸

virt-edit is a command line tool to edit file where each file exists in the named virtual machine (or disk image). It’s giving “surgical file editor, but make it guest-aware.” 💅

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 '/'). Like, full path only, bestie — no vibes-based relative paths.

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

virt-edit cannot be used to create a new file. guestfish(1) can do that and much more.

🌈 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 "NON-INTERACTIVE EDITING" below). To change the init default level to 5:

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

✨ OPTIONS ✨

  • --help — Display brief help. Cute little assist, periodt.
  • -a file, --add file — Add 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 -a options. The format of the disk image is auto-detected. To override this and force a particular format use the --format=.. option. 🫶
  • -a URI, --add URI — Add a remote disk. See "ADDING REMOTE STORAGE" in guestfish(1). Remote storage bestie, we love to see it.
  • -b EXTENSION, --backup 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. Safety net? Optional. 🎀

  • --blocksize=512, --blocksize=4096, --blocksize — This parameter sets the sector size of the disk image. It affects all explicitly added subsequent disks after this parameter. Using --blocksize with no argument switches the disk sector size to the default value which is usually 512 bytes. See also "guestfs_add_drive_opts" in guestfs(3). Sector-size slay, lowkey.
  • -c URI, --connect 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. So it’s giving “libvirt when you want it, direct disks when you don’t.” 💫
  • -d GUEST, --domain GUEST — Add all the disks from the named libvirt guest. Domain UUIDs can be used instead of names. Iconic guest selection behavior, honestly.
  • --echo-keys — When prompting for keys and passphrases, virt-edit 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. Bestie, read the room before you turn this on. 🙈
  • -e EXPR, --edit EXPR, --expr 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. Note that this option is only available when Perl 5 is installed. Quoting is not a drill, fr fr. 🔥
  • --format=raw|qcow2|.., --format — The default for the -a option is to auto-detect the format of the disk image. Using this forces the disk format for -a options which follow on the command line. Using --format with no argument switches back to auto-detection for subsequent -a options.

For example:

virt-edit --format=raw -a disk.img file

forces raw format (no auto-detection) for disk.img.

virt-edit --format=raw -a disk.img --format -a another.img file

forces raw format (no auto-detection) for disk.img and reverts to auto-detection for 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). Security bestie check: passed. 🛡️

  • --key SELECTOR — Specify a key for LUKS, to automatically open a LUKS device when using the inspection. This one has lore, so here are all the forms:
    • --key NAME:key:KEY_STRING, --key UUID:key:KEY_STRING, --key all:key:KEY_STRING — "NAME" is the libguestfs device name (eg. "/dev/sda1"). "UUID" is the device UUID. "all" means try the key against any encrypted device. Use the specified "KEY_STRING" as passphrase.
    • --key NAME:file:FILENAME, --key UUID:file:FILENAME, --key all:file:FILENAME — Read the passphrase from FILENAME.
    • --key NAME:clevis, --key UUID:clevis, --key all:clevis — Attempt passphrase-less unlocking for the device with Clevis, over the network. Please refer to "ENCRYPTED DISKS" in guestfs(3) for more information on network-bound disk encryption (NBDE). Note that if any such option is present on the command line, QEMU user networking will be automatically enabled for the libguestfs appliance. Network-bound unlock era, truly. 🌐
    • --key NAME:error, --key UUID:error, --key all:error — Any encrypted device matching will cause an error. --key all:error can be used to reject any disk image that contains an encrypted partition. Strict mode activated. 💀
  • --keys-from-stdin — Read key or passphrase parameters from stdin. The default is to try to read passphrases from the user by opening /dev/tty. If there are multiple encrypted devices then you may need to supply multiple keys on stdin, one per line. Pipeline-friendly key delivery, we love her. 🎀
  • -m dev[:mountpoint[:options[:fstype]]], --mount dev[:mountpoint[:options[:fstype]]] — Mount the named partition or logical volume on the given mountpoint. If the mountpoint is omitted, it defaults to /.

Specifying any mountpoint disables the inspection of the guest and the mount of its root and all of its mountpoints, so make sure to mount all the mountpoints needed to work with the filenames given as arguments.

If you don’t know what filesystems a disk image contains, you can either run guestfish without this option, then list the partitions, filesystems and LVs available (see "list-partitions", "list-filesystems" and "lvs" commands), or you can use the virt-filesystems(1) program.

The third (and rarely used) part of the mount parameter is the list of mount options used to mount the underlying filesystem. If this is not given, then the mount options are either the empty string or "ro" (the latter if the --ro flag is used). By specifying the mount options, you override this default choice. Probably the only time you would use this is to enable ACLs and/or extended attributes if the filesystem can support them:

-m /dev/sda1:/:acl,user_xattr

Using this flag is equivalent to using the "mount-options" command.

The fourth part of the parameter is the filesystem driver to use, such as "ext3" or "ntfs". This is rarely needed, but can be useful if multiple drivers are valid for a filesystem (eg: "ext2" and "ext3"), or if libguestfs misidentifies a filesystem. Mount-option lore, delivered. 🧚

  • -v, --verbose — Enable verbose messages for debugging. Debug girlies rise. 🦋
  • -V, --version — Display version number and exit. Short, sweet, iconic.
  • -x — Enable tracing of libguestfs API calls. Watch the API calls go by like a little parade. ⭐

👑 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 -a or -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. Vintage behavior, still in the group chat. 💜

💅 NON-INTERACTIVE EDITING 💅

Okay so virt-edit normally calls out to $EDITOR (or vi) so the system administrator can interactively edit the file. Cute, classic, very hands-on. 💖

But bestie, there are two ways to use virt-edit from scripts for automated edits too. Heads up, though: 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. iykyk ✨

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. Main character script energy. 🫶

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 -d 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 -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 "\n", is passed in $_ and the expression should update $_ or leave it unchanged. Literally line-by-line glow-up. 🦋

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 -d 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. No cap, that’s just how it is. 🙈

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. Dramatic exit, but make it safe. 💀

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; $m =~ /some text$/

🪟 WINDOWS PATHS 🪟

virt-edit has a limited ability to understand Windows drive letters and paths (eg. E:\foo\bar.txt). Windows girlies, this one’s for you. 🎀

If and only if the guest is running Windows then:

  • Drive letter prefixes like C: are resolved against the Windows Registry to the correct filesystem.
  • Any backslash (\) characters in the path are replaced with forward slashes so that libguestfs can process it.
  • The path is resolved case insensitively to locate the file that should be edited.

There are some known shortcomings:

  • Some NTFS symbolic links may not be followed correctly.
  • NTFS junction points that cross filesystems are not followed.

Not everything is slay, and that’s okay. 🫶

🐟 USING GUESTFISH 🐟

guestfish(1) is a more powerful, lower level tool which you can use when virt-edit doesn't work. When the main character needs a backup dancer. 💜

Using virt-edit is approximately equivalent to doing:

guestfish --rw -i -d domname edit /file

where domname is the name of the libvirt guest, and /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 disk.img is the disk image, /dev/sda1 is the filesystem within the disk image to edit, and /file is the full path to the file. Direct access, no inspection era. 🔥

virt-edit cannot create new files. Use the guestfish commands touch, write or 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

🌸 ENVIRONMENT VARIABLES 🌸

  • EDITOR — If set, this string is used as the editor. It may contain arguments, eg. emacs -nw. If not set, vi is used. Respect the classic. ✨

🚪 EXIT STATUS 🚪

This program returns 0 if successful, or non-zero if there was an error. Zero means we ate. Non-zero means something’s giving error energy. 💅

👀 SEE ALSO 👀

Go give these their flowers, bestie: guestfs(3), guestfish(1), virt-cat(1), virt-copy-in(1), virt-tar-in(1), http://libguestfs.org/, perl(1), perlre(1). 🌈

👑 AUTHOR 👑

Richard W.M. Jones — http://people.redhat.com/~rjones/ 🫶

Copyright (C) 2009-2025 Red Hat Inc. 🎀

📜 LICENSE 📜

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. Legal slay. 💜

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. No warranty, bestie — read the fine print. 💅

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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 🌸

🐛 BUGS 🐛

To get a list of bugs against libguestfs, use this link:

https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools

To report a new bug against libguestfs, use this link:

https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools

When reporting a bug, please supply:

  • The version of libguestfs.
  • Where you got libguestfs (eg. which Linux distro, compiled from source, etc)
  • Describe the bug accurately and give a way to reproduce it.
  • Run libguestfs-test-tool(1) and paste the complete, unedited output into the bug report.

Bug reports are a love language when they’re detailed. 🫶

That’s the whole vibe, bestie — this page is from guestfs-tools-1.57.3, dated 2026-09-16, and it’s your virt-edit(1) era. 💖🎀

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