1virt-edit(1)                Virtualization Support                virt-edit(1)
2
3
4

NAME

6       virt-edit - Edit a file in a virtual machine
7

SYNOPSIS

9        virt-edit [--options] -d domname file [file ...]
10
11        virt-edit [--options] -a disk.img [-a disk.img ...] file [file ...]
12
13        virt-edit [-d domname|-a disk.img] file -e 'expr'
14
15       Old-style:
16
17        virt-edit domname file
18
19        virt-edit disk.img [disk.img ...] file
20

WARNING

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

DESCRIPTION

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
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 '/').
34
35       If you want to just view a file, use virt-cat(1).
36
37       For more complex cases you should look at the guestfish(1) tool (see
38       "USING GUESTFISH" below).
39
40       "virt-edit" cannot be used to create a new file.  guestfish(1) can do
41       that and much more.
42

EXAMPLES

44       Edit the named files interactively:
45
46        virt-edit -d mydomain /boot/grub/grub.conf
47
48        virt-edit -d mydomain /etc/passwd
49
50       For Windows guests, some Windows paths are understood:
51
52        virt-edit -d mywindomain 'c:\autoexec.bat'
53
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:
57
58        virt-edit -d mydomain /etc/inittab -e 's/^id:.*/id:5:initdefault:/'
59

OPTIONS

61       --help
62           Display brief help.
63
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.
69
70           The format of the disk image is auto-detected.  To override this
71           and force a particular format use the --format=.. option.
72
73       -a URI
74       --add URI
75           Add a remote disk.  See "ADDING REMOTE STORAGE" in guestfish(1).
76
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.
81
82           Usually the first character of "extension" would be a dot "."  so
83           you would write:
84
85            virt-edit -b .orig [etc]
86
87           By default, no backup file is made.
88
89       --blocksize=512
90       --blocksize=4096
91       --blocksize
92           This parameter sets the sector size of the disk image.  It affects
93           all explicitly added subsequent disks after this parameter.  Using
94           --blocksize with no argument switches the disk sector size to the
95           default value which is usually 512 bytes.  See also
96           "guestfs_add_drive_opts" in guestfs(3).
97
98       -c URI
99       --connect URI
100           If using libvirt, connect to the given URI.  If omitted, then we
101           connect to the default libvirt hypervisor.
102
103           If you specify guest block devices directly, then libvirt is not
104           used at all.
105
106       -d GUEST
107       --domain GUEST
108           Add all the disks from the named libvirt guest.  Domain UUIDs can
109           be used instead of names.
110
111       --echo-keys
112           When prompting for keys and passphrases, virt-edit normally turns
113           echoing off so you cannot see what you are typing.  If you are not
114           worried about Tempest attacks and there is no one else in the room
115           you can specify this flag to see what you are typing.
116
117       -e EXPR
118       --edit EXPR
119       --expr EXPR
120           Instead of launching the external editor, non-interactively apply
121           the Perl expression "EXPR" to each line in the file.  See "NON-
122           INTERACTIVE EDITING" below.
123
124           Be careful to properly quote the expression to prevent it from
125           being altered by the shell.
126
127           Note that this option is only available when Perl 5 is installed.
128
129       --format=raw|qcow2|..
130       --format
131           The default for the -a option is to auto-detect the format of the
132           disk image.  Using this forces the disk format for -a options which
133           follow on the command line.  Using --format with no argument
134           switches back to auto-detection for subsequent -a options.
135
136           For example:
137
138            virt-edit --format=raw -a disk.img file
139
140           forces raw format (no auto-detection) for disk.img.
141
142            virt-edit --format=raw -a disk.img --format -a another.img file
143
144           forces raw format (no auto-detection) for disk.img and reverts to
145           auto-detection for another.img.
146
147           If you have untrusted raw-format guest disk images, you should use
148           this option to specify the disk format.  This avoids a possible
149           security problem with malicious guests (CVE-2010-3851).
150
151       --key SELECTOR
152           Specify a key for LUKS, to automatically open a LUKS device when
153           using the inspection.  "ID" can be either the libguestfs device
154           name, or the UUID of the LUKS device.
155
156           --key "ID":key:KEY_STRING
157               Use the specified "KEY_STRING" as passphrase.
158
159           --key "ID":file:FILENAME
160               Read the passphrase from FILENAME.
161
162           --key "ID":clevis
163               Attempt passphrase-less unlocking for "ID" with Clevis, over
164               the network.  Please refer to "ENCRYPTED DISKS" in guestfs(3)
165               for more information on network-bound disk encryption (NBDE).
166
167               Note that if any such option is present on the command line,
168               QEMU user networking will be automatically enabled for the
169               libguestfs appliance.
170
171       --keys-from-stdin
172           Read key or passphrase parameters from stdin.  The default is to
173           try to read passphrases from the user by opening /dev/tty.
174
175           If there are multiple encrypted devices then you may need to supply
176           multiple keys on stdin, one per line.
177
178       -m dev[:mountpoint[:options[:fstype]]]
179       --mount dev[:mountpoint[:options[:fstype]]]
180           Mount the named partition or logical volume on the given
181           mountpoint.
182
183           If the mountpoint is omitted, it defaults to /.
184
185           Specifying any mountpoint disables the inspection of the guest and
186           the mount of its root and all of its mountpoints, so make sure to
187           mount all the mountpoints needed to work with the filenames given
188           as arguments.
189
190           If you don’t know what filesystems a disk image contains, you can
191           either run guestfish without this option, then list the partitions,
192           filesystems and LVs available (see "list-partitions", "list-
193           filesystems" and "lvs" commands), or you can use the
194           virt-filesystems(1) program.
195
196           The third (and rarely used) part of the mount parameter is the list
197           of mount options used to mount the underlying filesystem.  If this
198           is not given, then the mount options are either the empty string or
199           "ro" (the latter if the --ro flag is used).  By specifying the
200           mount options, you override this default choice.  Probably the only
201           time you would use this is to enable ACLs and/or extended
202           attributes if the filesystem can support them:
203
204            -m /dev/sda1:/:acl,user_xattr
205
206           Using this flag is equivalent to using the "mount-options" command.
207
208           The fourth part of the parameter is the filesystem driver to use,
209           such as "ext3" or "ntfs". This is rarely needed, but can be useful
210           if multiple drivers are valid for a filesystem (eg: "ext2" and
211           "ext3"), or if libguestfs misidentifies a filesystem.
212
213       -v
214       --verbose
215           Enable verbose messages for debugging.
216
217       -V
218       --version
219           Display version number and exit.
220
221       -x  Enable tracing of libguestfs API calls.
222

OLD-STYLE COMMAND LINE ARGUMENTS

224       Previous versions of virt-edit allowed you to write either:
225
226        virt-edit disk.img [disk.img ...] file
227
228       or
229
230        virt-edit guestname file
231
232       whereas in this version you should use -a or -d respectively to avoid
233       the confusing case where a disk image might have the same name as a
234       guest.
235
236       For compatibility the old style is still supported.
237

NON-INTERACTIVE EDITING

239       "virt-edit" normally calls out to $EDITOR (or vi) so the system
240       administrator can interactively edit the file.
241
242       There are two ways also to use "virt-edit" from scripts in order to
243       make automated edits to files.  (Note that although you can use
244       "virt-edit" like this, it’s less error-prone to write scripts directly
245       using the libguestfs API and Augeas for configuration file editing.)
246
247       The first method is to temporarily set $EDITOR to any script or program
248       you want to run.  The script is invoked as "$EDITOR tmpfile" and it
249       should update "tmpfile" in place however it likes.
250
251       The second method is to use the -e parameter of "virt-edit" to run a
252       short Perl snippet in the style of sed(1).  For example to replace all
253       instances of "foo" with "bar" in a file:
254
255        virt-edit -d domname filename -e 's/foo/bar/'
256
257       The full power of Perl regular expressions can be used (see perlre(1)).
258       For example to delete root’s password you could do:
259
260        virt-edit -d domname /etc/passwd -e 's/^root:.*?:/root::/'
261
262       What really happens is that the snippet is evaluated as a Perl
263       expression for each line of the file.  The line, including the final
264       "\n", is passed in $_ and the expression should update $_ or leave it
265       unchanged.
266
267       To delete a line, set $_ to the empty string.  For example, to delete
268       the "apache" user account from the password file you can do:
269
270        virt-edit -d mydomain /etc/passwd -e '$_ = "" if /^apache:/'
271
272       To insert a line, prepend or append it to $_.  However appending lines
273       to the end of the file is rather difficult this way since there is no
274       concept of "last line of the file" - your expression just doesn't get
275       called again.  You might want to use the first method (setting $EDITOR)
276       if you want to do this.
277
278       The variable $lineno contains the current line number.  As is
279       traditional, the first line in the file is number 1.
280
281       The return value from the expression is ignored, but the expression may
282       call "die" in order to abort the whole program, leaving the original
283       file untouched.
284
285       Remember when matching the end of a line that $_ may contain the final
286       "\n", or (for DOS files) "\r\n", or if the file does not end with a
287       newline then neither of these.  Thus to match or substitute some text
288       at the end of a line, use this regular expression:
289
290        /some text(\r?\n)?$/
291
292       Alternately, use the perl "chomp" function, being careful not to chomp
293       $_ itself (since that would remove all newlines from the file):
294
295        my $m = $_; chomp $m; $m =~ /some text$/
296

WINDOWS PATHS

298       "virt-edit" has a limited ability to understand Windows drive letters
299       and paths (eg. E:\foo\bar.txt).
300
301       If and only if the guest is running Windows then:
302
303       •   Drive letter prefixes like "C:" are resolved against the Windows
304           Registry to the correct filesystem.
305
306       •   Any backslash ("\") characters in the path are replaced with
307           forward slashes so that libguestfs can process it.
308
309       •   The path is resolved case insensitively to locate the file that
310           should be edited.
311
312       There are some known shortcomings:
313
314       •   Some NTFS symbolic links may not be followed correctly.
315
316       •   NTFS junction points that cross filesystems are not followed.
317

USING GUESTFISH

319       guestfish(1) is a more powerful, lower level tool which you can use
320       when "virt-edit" doesn't work.
321
322       Using "virt-edit" is approximately equivalent to doing:
323
324        guestfish --rw -i -d domname edit /file
325
326       where "domname" is the name of the libvirt guest, and /file is the full
327       path to the file.
328
329       The command above uses libguestfs’s guest inspection feature and so
330       does not work on guests that libguestfs cannot inspect, or on things
331       like arbitrary disk images that don't contain guests.  To edit a file
332       on a disk image directly, use:
333
334        guestfish --rw -a disk.img -m /dev/sda1 edit /file
335
336       where disk.img is the disk image, /dev/sda1 is the filesystem within
337       the disk image to edit, and /file is the full path to the file.
338
339       "virt-edit" cannot create new files.  Use the guestfish commands
340       "touch", "write" or "upload" instead:
341
342        guestfish --rw -i -d domname touch /newfile
343
344        guestfish --rw -i -d domname write /newfile "new content"
345
346        guestfish --rw -i -d domname upload localfile /newfile
347

ENVIRONMENT VARIABLES

349       "EDITOR"
350           If set, this string is used as the editor.  It may contain
351           arguments, eg. "emacs -nw"
352
353           If not set, "vi" is used.
354

EXIT STATUS

356       This program returns 0 if successful, or non-zero if there was an
357       error.
358

SEE ALSO

360       guestfs(3), guestfish(1), virt-cat(1), virt-copy-in(1), virt-tar-in(1),
361       http://libguestfs.org/, perl(1), perlre(1).
362

AUTHOR

364       Richard W.M. Jones http://people.redhat.com/~rjones/
365
367       Copyright (C) 2009-2023 Red Hat Inc.
368

LICENSE

370       This program is free software; you can redistribute it and/or modify it
371       under the terms of the GNU General Public License as published by the
372       Free Software Foundation; either version 2 of the License, or (at your
373       option) any later version.
374
375       This program is distributed in the hope that it will be useful, but
376       WITHOUT ANY WARRANTY; without even the implied warranty of
377       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
378       General Public License for more details.
379
380       You should have received a copy of the GNU General Public License along
381       with this program; if not, write to the Free Software Foundation, Inc.,
382       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
383

BUGS

385       To get a list of bugs against libguestfs, use this link:
386       https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
387
388       To report a new bug against libguestfs, use this link:
389       https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
390
391       When reporting a bug, please supply:
392
393       •   The version of libguestfs.
394
395       •   Where you got libguestfs (eg. which Linux distro, compiled from
396           source, etc)
397
398       •   Describe the bug accurately and give a way to reproduce it.
399
400       •   Run libguestfs-test-tool(1) and paste the complete, unedited output
401           into the bug report.
402
403
404
405guestfs-tools-1.50.1              2023-04-06                      virt-edit(1)
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