1virt-edit(1) Virtualization Support virt-edit(1)
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6 virt-edit - Edit a file in a virtual machine
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9 virt-edit [--options] -d domname file [file ...]
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11 virt-edit [--options] -a disk.img [-a disk.img ...] file [file ...]
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13 virt-edit [-d domname|-a disk.img] file -e 'expr'
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15 Old-style:
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17 virt-edit domname file
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19 virt-edit disk.img [disk.img ...] file
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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.
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28 "virt-edit" is a command line tool to edit "file" where each "file"
29 exists in the named virtual machine (or disk image).
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31 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 '/').
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35 If you want to just view a file, use virt-cat(1).
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37 For more complex cases you should look at the guestfish(1) tool (see
38 "USING GUESTFISH" below).
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40 "virt-edit" cannot be used to create a new file. guestfish(1) can do
41 that and much more.
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44 Edit the named files interactively:
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46 virt-edit -d mydomain /boot/grub/grub.conf
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48 virt-edit -d mydomain /etc/passwd
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50 For Windows guests, some Windows paths are understood:
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52 virt-edit -d mywindomain 'c:\autoexec.bat'
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54 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:
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58 virt-edit -d mydomain /etc/inittab -e 's/^id:.*/id:5:initdefault:/'
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61 --help
62 Display brief help.
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64 -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.
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70 The format of the disk image is auto-detected. To override this
71 and force a particular format use the --format=.. option.
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73 -a URI
74 --add URI
75 Add a remote disk. See "ADDING REMOTE STORAGE" in guestfish(1).
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77 -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.
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82 Usually the first character of "extension" would be a dot "." so
83 you would write:
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85 virt-edit -b .orig [etc]
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87 By default, no backup file is made.
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89 -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.
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94 If you specify guest block devices directly, then libvirt is not
95 used at all.
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97 -d GUEST
98 --domain GUEST
99 Add all the disks from the named libvirt guest. Domain UUIDs can
100 be used instead of names.
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102 --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.
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108 -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.
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115 Be careful to properly quote the expression to prevent it from
116 being altered by the shell.
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118 Note that this option is only available when Perl 5 is installed.
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120 --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.
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127 For example:
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129 virt-edit --format=raw -a disk.img file
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131 forces raw format (no auto-detection) for disk.img.
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133 virt-edit --format=raw -a disk.img --format -a another.img file
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135 forces raw format (no auto-detection) for disk.img and reverts to
136 auto-detection for another.img.
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138 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
142 --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:
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147 --key "DEVICE":key:KEY_STRING
148 Use the specified "KEY_STRING" as passphrase.
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150 --key "DEVICE":file:FILENAME
151 Read the passphrase from FILENAME.
152
153 --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
157 -m dev[:mountpoint[:options[:fstype]]]
158 --mount dev[:mountpoint[:options[:fstype]]]
159 Mount the named partition or logical volume on the given
160 mountpoint.
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162 If the mountpoint is omitted, it defaults to /.
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164 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.
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169 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
175 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:
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183 -m /dev/sda1:/:acl,user_xattr
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185 Using this flag is equivalent to using the "mount-options" command.
186
187 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.
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192 -v
193 --verbose
194 Enable verbose messages for debugging.
195
196 -V
197 --version
198 Display version number and exit.
199
200 -x Enable tracing of libguestfs API calls.
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203 Previous versions of virt-edit allowed you to write either:
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205 virt-edit disk.img [disk.img ...] file
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207 or
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209 virt-edit guestname file
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211 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.
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215 For compatibility the old style is still supported.
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218 "virt-edit" normally calls out to $EDITOR (or vi) so the system
219 administrator can interactively edit the file.
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221 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.)
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226 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.
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230 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:
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234 virt-edit -d domname filename -e 's/foo/bar/'
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236 The full power of Perl regular expressions can be used (see perlre(1)).
237 For example to delete root’s password you could do:
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239 virt-edit -d domname /etc/passwd -e 's/^root:.*?:/root::/'
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241 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.
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246 To delete a line, set $_ to the empty string. For example, to delete
247 the "apache" user account from the password file you can do:
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249 virt-edit -d mydomain /etc/passwd -e '$_ = "" if /^apache:/'
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251 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.
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257 The variable $lineno contains the current line number. As is
258 traditional, the first line in the file is number 1.
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260 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.
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264 Remember when matching the end of a line that $_ may contain the final
265 "\n", or (for DOS files) "\r\n", or if the file does not end with a
266 newline then neither of these. Thus to match or substitute some text
267 at the end of a line, use this regular expression:
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269 /some text(\r?\n)?$/
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271 Alternately, use the perl "chomp" function, being careful not to chomp
272 $_ itself (since that would remove all newlines from the file):
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274 my $m = $_; chomp $m; $m =~ /some text$/
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277 "virt-edit" has a limited ability to understand Windows drive letters
278 and paths (eg. E:\foo\bar.txt).
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280 If and only if the guest is running Windows then:
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282 · Drive letter prefixes like "C:" are resolved against the Windows
283 Registry to the correct filesystem.
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285 · Any backslash ("\") characters in the path are replaced with
286 forward slashes so that libguestfs can process it.
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288 · The path is resolved case insensitively to locate the file that
289 should be edited.
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291 There are some known shortcomings:
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293 · Some NTFS symbolic links may not be followed correctly.
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295 · NTFS junction points that cross filesystems are not followed.
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298 guestfish(1) is a more powerful, lower level tool which you can use
299 when "virt-edit" doesn't work.
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301 Using "virt-edit" is approximately equivalent to doing:
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303 guestfish --rw -i -d domname edit /file
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305 where "domname" is the name of the libvirt guest, and /file is the full
306 path to the file.
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308 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:
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313 guestfish --rw -a disk.img -m /dev/sda1 edit /file
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315 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.
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318 "virt-edit" cannot create new files. Use the guestfish commands
319 "touch", "write" or "upload" instead:
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321 guestfish --rw -i -d domname touch /newfile
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323 guestfish --rw -i -d domname write /newfile "new content"
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325 guestfish --rw -i -d domname upload localfile /newfile
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328 "EDITOR"
329 If set, this string is used as the editor. It may contain
330 arguments, eg. "emacs -nw"
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332 If not set, "vi" is used.
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335 This program returns 0 if successful, or non-zero if there was an
336 error.
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339 guestfs(3), guestfish(1), virt-cat(1), virt-copy-in(1), virt-tar-in(1),
340 http://libguestfs.org/, perl(1), perlre(1).
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343 Richard W.M. Jones http://people.redhat.com/~rjones/
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346 Copyright (C) 2009-2019 Red Hat Inc.
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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
354 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
359 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
367 To report a new bug against libguestfs, use this link:
368 https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
369
370 When reporting a bug, please supply:
371
372 · The version of libguestfs.
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374 · Where you got libguestfs (eg. which Linux distro, compiled from
375 source, etc)
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377 · Describe the bug accurately and give a way to reproduce it.
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379 · Run libguestfs-test-tool(1) and paste the complete, unedited output
380 into the bug report.
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384libguestfs-1.40.2 2019-02-07 virt-edit(1)