1virt-cat(1)                 Virtualization Support                 virt-cat(1)
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NAME

6       virt-cat - Display files in a virtual machine
7

SYNOPSIS

9        virt-cat [--options] -d domname file [file ...]
10
11        virt-cat [--options] -a disk.img [-a disk.img ...] file [file ...]
12
13       Old-style:
14
15        virt-cat domname file
16
17        virt-cat disk.img file
18

DESCRIPTION

20       "virt-cat" is a command line tool to display the contents of "file"
21       where "file" exists in the named virtual machine (or disk image).
22
23       Multiple filenames can be given, in which case they are concatenated
24       together.  Each filename must be a full path, starting at the root
25       directory (starting with '/').
26
27       "virt-cat" can be used to quickly view a file.  To edit a file, use
28       "virt-edit".  For more complex cases you should look at the
29       guestfish(1) tool (see "USING GUESTFISH" below).
30

EXAMPLES

32       Display /etc/fstab file from inside the libvirt VM called "mydomain":
33
34        virt-cat -d mydomain /etc/fstab
35
36       Find out what packages were recently installed:
37
38        virt-cat -d mydomain /var/log/yum.log | tail
39
40       Find out who is logged on inside a virtual machine:
41
42        virt-cat -d mydomain /var/run/utmp > /tmp/utmp
43        who /tmp/utmp
44
45       or who was logged on:
46
47        virt-cat -d mydomain /var/log/wtmp > /tmp/wtmp
48        last -f /tmp/wtmp
49

OPTIONS

51       --help
52           Display brief help.
53
54       -a file
55       --add file
56           Add file which should be a disk image from a virtual machine.  If
57           the virtual machine has multiple block devices, you must supply all
58           of them with separate -a options.
59
60           The format of the disk image is auto-detected.  To override this
61           and force a particular format use the --format=.. option.
62
63       -a URI
64       --add URI
65           Add a remote disk.  See "ADDING REMOTE STORAGE" in guestfish(1).
66
67       --blocksize=512
68       --blocksize=4096
69       --blocksize
70           This parameter sets the sector size of the disk image.  It affects
71           all explicitly added subsequent disks after this parameter.  Using
72           --blocksize with no argument switches the disk sector size to the
73           default value which is usually 512 bytes.  See also
74           "guestfs_add_drive_opts" in guestfs(3).
75
76       -c URI
77       --connect URI
78           If using libvirt, connect to the given URI.  If omitted, then we
79           connect to the default libvirt hypervisor.
80
81           If you specify guest block devices directly (-a), then libvirt is
82           not used at all.
83
84       -d guest
85       --domain guest
86           Add all the disks from the named libvirt guest.  Domain UUIDs can
87           be used instead of names.
88
89       --echo-keys
90           When prompting for keys and passphrases, virt-cat normally turns
91           echoing off so you cannot see what you are typing.  If you are not
92           worried about Tempest attacks and there is no one else in the room
93           you can specify this flag to see what you are typing.
94
95       --format=raw|qcow2|..
96       --format
97           The default for the -a option is to auto-detect the format of the
98           disk image.  Using this forces the disk format for -a options which
99           follow on the command line.  Using --format with no argument
100           switches back to auto-detection for subsequent -a options.
101
102           For example:
103
104            virt-cat --format=raw -a disk.img file
105
106           forces raw format (no auto-detection) for disk.img.
107
108            virt-cat --format=raw -a disk.img --format -a another.img file
109
110           forces raw format (no auto-detection) for disk.img and reverts to
111           auto-detection for another.img.
112
113           If you have untrusted raw-format guest disk images, you should use
114           this option to specify the disk format.  This avoids a possible
115           security problem with malicious guests (CVE-2010-3851).
116
117       --key SELECTOR
118           Specify a key for LUKS, to automatically open a LUKS device when
119           using the inspection.  "ID" can be either the libguestfs device
120           name, or the UUID of the LUKS device.
121
122           --key "ID":key:KEY_STRING
123               Use the specified "KEY_STRING" as passphrase.
124
125           --key "ID":file:FILENAME
126               Read the passphrase from FILENAME.
127
128       --keys-from-stdin
129           Read key or passphrase parameters from stdin.  The default is to
130           try to read passphrases from the user by opening /dev/tty.
131
132           If there are multiple encrypted devices then you may need to supply
133           multiple keys on stdin, one per line.
134
135       -m dev[:mountpoint[:options[:fstype]]]
136       --mount dev[:mountpoint[:options[:fstype]]]
137           Mount the named partition or logical volume on the given
138           mountpoint.
139
140           If the mountpoint is omitted, it defaults to /.
141
142           Specifying any mountpoint disables the inspection of the guest and
143           the mount of its root and all of its mountpoints, so make sure to
144           mount all the mountpoints needed to work with the filenames given
145           as arguments.
146
147           If you don’t know what filesystems a disk image contains, you can
148           either run guestfish without this option, then list the partitions,
149           filesystems and LVs available (see "list-partitions", "list-
150           filesystems" and "lvs" commands), or you can use the
151           virt-filesystems(1) program.
152
153           The third (and rarely used) part of the mount parameter is the list
154           of mount options used to mount the underlying filesystem.  If this
155           is not given, then the mount options are either the empty string or
156           "ro" (the latter if the --ro flag is used).  By specifying the
157           mount options, you override this default choice.  Probably the only
158           time you would use this is to enable ACLs and/or extended
159           attributes if the filesystem can support them:
160
161            -m /dev/sda1:/:acl,user_xattr
162
163           Using this flag is equivalent to using the "mount-options" command.
164
165           The fourth part of the parameter is the filesystem driver to use,
166           such as "ext3" or "ntfs". This is rarely needed, but can be useful
167           if multiple drivers are valid for a filesystem (eg: "ext2" and
168           "ext3"), or if libguestfs misidentifies a filesystem.
169
170       -v
171       --verbose
172           Enable verbose messages for debugging.
173
174       -V
175       --version
176           Display version number and exit.
177
178       -x  Enable tracing of libguestfs API calls.
179

OLD-STYLE COMMAND LINE ARGUMENTS

181       Previous versions of virt-cat allowed you to write either:
182
183        virt-cat disk.img [disk.img ...] file
184
185       or
186
187        virt-cat guestname file
188
189       whereas in this version you should use -a or -d respectively to avoid
190       the confusing case where a disk image might have the same name as a
191       guest.
192
193       For compatibility the old style is still supported.
194

LOG FILES

196       To list out the log files from guests, see the related tool
197       virt-log(1).  It understands binary log formats such as the systemd
198       journal.
199
200       To follow (tail) text log files, use virt-tail(1).
201

WINDOWS PATHS

203       "virt-cat" has a limited ability to understand Windows drive letters
204       and paths (eg. E:\foo\bar.txt).
205
206       If and only if the guest is running Windows then:
207
208       •   Drive letter prefixes like "C:" are resolved against the Windows
209           Registry to the correct filesystem.
210
211       •   Any backslash ("\") characters in the path are replaced with
212           forward slashes so that libguestfs can process it.
213
214       •   The path is resolved case insensitively to locate the file that
215           should be displayed.
216
217       There are some known shortcomings:
218
219       •   Some NTFS symbolic links may not be followed correctly.
220
221       •   NTFS junction points that cross filesystems are not followed.
222

USING GUESTFISH

224       guestfish(1) is a more powerful, lower level tool which you can use
225       when "virt-cat" doesn't work.
226
227       Using "virt-cat" is approximately equivalent to doing:
228
229        guestfish --ro -i -d domname download file -
230
231       where "domname" is the name of the libvirt guest, and "file" is the
232       full path to the file.  Note the final "-" (meaning "output to
233       stdout").
234
235       The command above uses libguestfs’s guest inspection feature and so
236       does not work on guests that libguestfs cannot inspect, or on things
237       like arbitrary disk images that don't contain guests.  To display a
238       file from a disk image directly, use:
239
240        guestfish --ro -a disk.img -m /dev/sda1 download file -
241
242       where disk.img is the disk image, /dev/sda1 is the filesystem within
243       the disk image, and "file" is the full path to the file.
244

EXIT STATUS

246       This program returns 0 if successful, or non-zero if there was an
247       error.
248

SEE ALSO

250       guestfs(3), guestfish(1), virt-copy-out(1), virt-edit(1), virt-log(1),
251       virt-tail(1), virt-tar-out(1), http://libguestfs.org/.
252

AUTHOR

254       Richard W.M. Jones http://people.redhat.com/~rjones/
255
257       Copyright (C) 2010-2012 Red Hat Inc.
258

LICENSE

260       This program is free software; you can redistribute it and/or modify it
261       under the terms of the GNU General Public License as published by the
262       Free Software Foundation; either version 2 of the License, or (at your
263       option) any later version.
264
265       This program is distributed in the hope that it will be useful, but
266       WITHOUT ANY WARRANTY; without even the implied warranty of
267       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
268       General Public License for more details.
269
270       You should have received a copy of the GNU General Public License along
271       with this program; if not, write to the Free Software Foundation, Inc.,
272       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
273

BUGS

275       To get a list of bugs against libguestfs, use this link:
276       https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools
277
278       To report a new bug against libguestfs, use this link:
279       https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools
280
281       When reporting a bug, please supply:
282
283       •   The version of libguestfs.
284
285       •   Where you got libguestfs (eg. which Linux distro, compiled from
286           source, etc)
287
288       •   Describe the bug accurately and give a way to reproduce it.
289
290       •   Run libguestfs-test-tool(1) and paste the complete, unedited output
291           into the bug report.
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294
295guestfs-tools-1.46.1              2021-05-13                       virt-cat(1)
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