1virt-edit(1) Virtualization Support virt-edit(1)
2
6 virt-edit - Edit a file in a virtual machine
7
9 virt-edit [--options] -d domname file [file ...]
10 virt-edit [--options] -a disk.img [-a disk.img ...] file [file ...]
12 virt-edit [-d domname|-a disk.img] file -e 'expr'
14 Old-style:
16 virt-edit domname file
18 virt-edit disk.img [disk.img ...] file
20
22 Using "virt-edit" on live virtual machines, or concurrently with other
23 disk editing tools, can be dangerous, potentially causing disk
24 corruption. The virtual machine must be shut down before you use this
25 command, and disk images must not be edited concurrently.
26
28 "virt-edit" is a command line tool to edit "file" where each "file"
29 exists in the named virtual machine (or disk image).
30 Multiple filenames can be given, in which case they are each edited in
32 turn. Each filename must be a full path, starting at the root
33 directory (starting with '/').
34 If you want to just view a file, use virt-cat(1).
36 For more complex cases you should look at the guestfish(1) tool (see
38 "USING GUESTFISH" below).
39 "virt-edit" cannot be used to create a new file. guestfish(1) can do
41 that and much more.
42
44 Edit the named files interactively:
45 virt-edit -d mydomain /boot/grub/grub.conf
47 virt-edit -d mydomain /etc/passwd
49 For Windows guests, some Windows paths are understood:
51 virt-edit -d mywindomain 'c:\autoexec.bat'
53 If Perl is installed, you can also edit files non-interactively (see
55 "NON-INTERACTIVE EDITING" below). To change the init default level to
56 5:
57 virt-edit -d mydomain /etc/inittab -e 's/^id:.*/id:5:initdefault:/'
59
61 --help
62 Display brief help.
63 -a file
65 --add file
66 Add file which should be a disk image from a virtual machine. If
67 the virtual machine has multiple block devices, you must supply all
68 of them with separate -a options.
69 The format of the disk image is auto-detected. To override this
71 and force a particular format use the --format=.. option.
72 -a URI
74 --add URI
75 Add a remote disk. See "ADDING REMOTE STORAGE" in guestfish(1).
76 -b EXTENSION
78 --backup EXTENSION
79 Create a backup of the original file in the guest disk image. The
80 backup has the original filename with "extension" added.
81 Usually the first character of "extension" would be a dot "." so
83 you would write:
84 virt-edit -b .orig [etc]
86 By default, no backup file is made.
88 -c URI
90 --connect URI
91 If using libvirt, connect to the given URI. If omitted, then we
92 connect to the default libvirt hypervisor.
93 If you specify guest block devices directly, then libvirt is not
95 used at all.
96 -d GUEST
98 --domain GUEST
99 Add all the disks from the named libvirt guest. Domain UUIDs can
100 be used instead of names.
101 --echo-keys
103 When prompting for keys and passphrases, virt-edit normally turns
104 echoing off so you cannot see what you are typing. If you are not
105 worried about Tempest attacks and there is no one else in the room
106 you can specify this flag to see what you are typing.
107 -e EXPR
109 --edit EXPR
110 --expr EXPR
111 Instead of launching the external editor, non-interactively apply
112 the Perl expression "EXPR" to each line in the file. See "NON-
113 INTERACTIVE EDITING" below.
114 Be careful to properly quote the expression to prevent it from
116 being altered by the shell.
117 Note that this option is only available when Perl 5 is installed.
119 --format=raw|qcow2|..
121 --format
122 The default for the -a option is to auto-detect the format of the
123 disk image. Using this forces the disk format for -a options which
124 follow on the command line. Using --format with no argument
125 switches back to auto-detection for subsequent -a options.
126 For example:
128 virt-edit --format=raw -a disk.img file
130 forces raw format (no auto-detection) for disk.img.
132 virt-edit --format=raw -a disk.img --format -a another.img file
134 forces raw format (no auto-detection) for disk.img and reverts to
136 auto-detection for another.img.
137 If you have untrusted raw-format guest disk images, you should use
139 this option to specify the disk format. This avoids a possible
140 security problem with malicious guests (CVE-2010-3851).
141 --key SELECTOR
143 Specify a key for LUKS, to automatically open a LUKS device when
144 using the inspection. "SELECTOR" can be in one of the following
145 formats:
146 --key "DEVICE":key:KEY_STRING
148 Use the specified "KEY_STRING" as passphrase.
149 --key "DEVICE":file:FILENAME
151 Read the passphrase from FILENAME.
152 --keys-from-stdin
154 Read key or passphrase parameters from stdin. The default is to
155 try to read passphrases from the user by opening /dev/tty.
156 -m dev[:mountpoint[:options[:fstype]]]
158 --mount dev[:mountpoint[:options[:fstype]]]
159 Mount the named partition or logical volume on the given
160 mountpoint.
161 If the mountpoint is omitted, it defaults to /.
163 Specifying any mountpoint disables the inspection of the guest and
165 the mount of its root and all of its mountpoints, so make sure to
166 mount all the mountpoints needed to work with the filenames given
167 as arguments.
168 If you don’t know what filesystems a disk image contains, you can
170 either run guestfish without this option, then list the partitions,
171 filesystems and LVs available (see "list-partitions", "list-
172 filesystems" and "lvs" commands), or you can use the
173 virt-filesystems(1) program.
174 The third (and rarely used) part of the mount parameter is the list
176 of mount options used to mount the underlying filesystem. If this
177 is not given, then the mount options are either the empty string or
178 "ro" (the latter if the --ro flag is used). By specifying the
179 mount options, you override this default choice. Probably the only
180 time you would use this is to enable ACLs and/or extended
181 attributes if the filesystem can support them:
182 -m /dev/sda1:/:acl,user_xattr
184 Using this flag is equivalent to using the "mount-options" command.
186 The fourth part of the parameter is the filesystem driver to use,
188 such as "ext3" or "ntfs". This is rarely needed, but can be useful
189 if multiple drivers are valid for a filesystem (eg: "ext2" and
190 "ext3"), or if libguestfs misidentifies a filesystem.
191 -v
193 --verbose
194 Enable verbose messages for debugging.
195 -V
197 --version
198 Display version number and exit.
199 -x Enable tracing of libguestfs API calls.
201
203 Previous versions of virt-edit allowed you to write either:
204 virt-edit disk.img [disk.img ...] file
206 or
208 virt-edit guestname file
210 whereas in this version you should use -a or -d respectively to avoid
212 the confusing case where a disk image might have the same name as a
213 guest.
214 For compatibility the old style is still supported.
216
218 "virt-edit" normally calls out to $EDITOR (or vi) so the system
219 administrator can interactively edit the file.
220 There are two ways also to use "virt-edit" from scripts in order to
222 make automated edits to files. (Note that although you can use
223 "virt-edit" like this, it’s less error-prone to write scripts directly
224 using the libguestfs API and Augeas for configuration file editing.)
225 The first method is to temporarily set $EDITOR to any script or program
227 you want to run. The script is invoked as "$EDITOR tmpfile" and it
228 should update "tmpfile" in place however it likes.
229 The second method is to use the -e parameter of "virt-edit" to run a
231 short Perl snippet in the style of sed(1). For example to replace all
232 instances of "foo" with "bar" in a file:
233 virt-edit -d domname filename -e 's/foo/bar/'
235 The full power of Perl regular expressions can be used (see perlre(1)).
237 For example to delete root’s password you could do:
238 virt-edit -d domname /etc/passwd -e 's/^root:.*?:/root::/'
240 What really happens is that the snippet is evaluated as a Perl
242 expression for each line of the file. The line, including the final
243 "\n", is passed in $_ and the expression should update $_ or leave it
244 unchanged.
245 To delete a line, set $_ to the empty string. For example, to delete
247 the "apache" user account from the password file you can do:
248 virt-edit -d mydomain /etc/passwd -e '$_ = "" if /^apache:/'
250 To insert a line, prepend or append it to $_. However appending lines
252 to the end of the file is rather difficult this way since there is no
253 concept of "last line of the file" - your expression just doesn't get
254 called again. You might want to use the first method (setting $EDITOR)
255 if you want to do this.
256 The variable $lineno contains the current line number. As is
258 traditional, the first line in the file is number 1.
259 The return value from the expression is ignored, but the expression may
261 call "die" in order to abort the whole program, leaving the original
262 file untouched.
263 Remember when matching the end of a line that $_ may contain the final
265 "\n", or (for DOS files) "\r\n", or if the file does not end with a
266 newline then neither of these. Thus to match or substitute some text
267 at the end of a line, use this regular expression:
268 /some text(\r?\n)?$/
270 Alternately, use the perl "chomp" function, being careful not to chomp
272 $_ itself (since that would remove all newlines from the file):
273 my $m = $_; chomp $m; $m =~ /some text$/
275
277 "virt-edit" has a limited ability to understand Windows drive letters
278 and paths (eg. E:\foo\bar.txt).
279 If and only if the guest is running Windows then:
281 · Drive letter prefixes like "C:" are resolved against the Windows
283 Registry to the correct filesystem.
284 · Any backslash ("\") characters in the path are replaced with
286 forward slashes so that libguestfs can process it.
287 · The path is resolved case insensitively to locate the file that
289 should be edited.
290 There are some known shortcomings:
292 · Some NTFS symbolic links may not be followed correctly.
294 · NTFS junction points that cross filesystems are not followed.
296
298 guestfish(1) is a more powerful, lower level tool which you can use
299 when "virt-edit" doesn't work.
300 Using "virt-edit" is approximately equivalent to doing:
302 guestfish --rw -i -d domname edit /file
304 where "domname" is the name of the libvirt guest, and /file is the full
306 path to the file.
307 The command above uses libguestfs’s guest inspection feature and so
309 does not work on guests that libguestfs cannot inspect, or on things
310 like arbitrary disk images that don't contain guests. To edit a file
311 on a disk image directly, use:
312 guestfish --rw -a disk.img -m /dev/sda1 edit /file
314 where disk.img is the disk image, /dev/sda1 is the filesystem within
316 the disk image to edit, and /file is the full path to the file.
317 "virt-edit" cannot create new files. Use the guestfish commands
319 "touch", "write" or "upload" instead:
320 guestfish --rw -i -d domname touch /newfile
322 guestfish --rw -i -d domname write /newfile "new content"
324 guestfish --rw -i -d domname upload localfile /newfile
326
328 "EDITOR"
329 If set, this string is used as the editor. It may contain
330 arguments, eg. "emacs -nw"
331 If not set, "vi" is used.
333
335 This program returns 0 if successful, or non-zero if there was an
336 error.
337
339 guestfs(3), guestfish(1), virt-cat(1), virt-copy-in(1), virt-tar-in(1),
340 http://libguestfs.org/, perl(1), perlre(1).
341
343 Richard W.M. Jones http://people.redhat.com/~rjones/
344
346 Copyright (C) 2009-2019 Red Hat Inc.
347
349 This program is free software; you can redistribute it and/or modify it
350 under the terms of the GNU General Public License as published by the
351 Free Software Foundation; either version 2 of the License, or (at your
352 option) any later version.
353 This program is distributed in the hope that it will be useful, but
355 WITHOUT ANY WARRANTY; without even the implied warranty of
356 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
357 General Public License for more details.
358 You should have received a copy of the GNU General Public License along
360 with this program; if not, write to the Free Software Foundation, Inc.,
361 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
362
364 To get a list of bugs against libguestfs, use this link:
365 https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
366 To report a new bug against libguestfs, use this link:
368 https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
369 When reporting a bug, please supply:
371 · The version of libguestfs.
373 · Where you got libguestfs (eg. which Linux distro, compiled from
375 source, etc)
376 · Describe the bug accurately and give a way to reproduce it.
378 · Run libguestfs-test-tool(1) and paste the complete, unedited output
380 into the bug report.
381libguestfs-1.40.1 2019-01-17 virt-edit(1)