libguestfs/fish/guestfish.pod

=head1 NAME

guestfish - the guest filesystem shell

=head1 SYNOPSIS

 guestfish [--options] [commands]

 guestfish

 guestfish [--ro|--rw] -a disk.img

 guestfish [--ro|--rw] -a disk.img -m dev[:mountpoint]

 guestfish -d libvirt-domain

 guestfish [--ro|--rw] -a disk.img -i

 guestfish -d libvirt-domain -i

=head1 DESCRIPTION

Guestfish is a shell and command-line tool for examining and modifying
virtual machine filesystems.  It uses libguestfs and exposes all of
the functionality of the guestfs API, see L<guestfs(3)>.

Guestfish gives you structured access to the libguestfs API, from
shell scripts or the command line or interactively.  If you want to
rescue a broken virtual machine image, you should look at the
L<virt-rescue(1)> command.

=head1 EXAMPLES

=head2 As an interactive shell

 $ guestfish
 
 Welcome to guestfish, the guest filesystem shell for
 editing virtual machine filesystems.
 
 Type: 'help' for a list of commands
       'man' to read the manual
       'quit' to quit the shell
 
 ><fs> add-ro disk.img
 ><fs> run
 ><fs> list-filesystems
 /dev/sda1: ext4
 /dev/vg_guest/lv_root: ext4
 /dev/vg_guest/lv_swap: swap
 ><fs> mount /dev/vg_guest/lv_root /
 ><fs> cat /etc/fstab
 # /etc/fstab
 # Created by anaconda
 [...]
 ><fs> exit

=head2 From shell scripts

Create a new F</etc/motd> file in a guest or disk image:

 guestfish <<_EOF_
 add disk.img
 run
 mount /dev/vg_guest/lv_root /
 write /etc/motd "Welcome, new users"
 _EOF_

List the LVM logical volumes in a disk image:

 guestfish -a disk.img --ro <<_EOF_
 run
 lvs
 _EOF_

List all the filesystems in a disk image:

 guestfish -a disk.img --ro <<_EOF_
 run
 list-filesystems
 _EOF_

=head2 On one command line

Update F</etc/resolv.conf> in a guest:

 guestfish \
   add disk.img : run : mount /dev/vg_guest/lv_root / : \
   write /etc/resolv.conf "nameserver 1.2.3.4"

Edit F</boot/grub/grub.conf> interactively:

 guestfish --rw --add disk.img \
   --mount /dev/vg_guest/lv_root \
   --mount /dev/sda1:/boot \
   edit /boot/grub/grub.conf

=head2 Mount disks automatically

Use the I<-i> option to automatically mount the
disks from a virtual machine:

 guestfish --ro -a disk.img -i cat /etc/group

 guestfish --ro -d libvirt-domain -i cat /etc/group

Another way to edit F</boot/grub/grub.conf> interactively is:

 guestfish --rw -a disk.img -i edit /boot/grub/grub.conf

=head2 As a script interpreter

Create a 100MB disk containing an ext2-formatted partition:

 #!/usr/bin/guestfish -f
 sparse test1.img 100M
 run
 part-disk /dev/sda mbr
 mkfs ext2 /dev/sda1

=head2 Start with a prepared disk

Create a 1G disk called F<test1.img> containing a single
ext2-formatted partition:

 guestfish -N fs

To list what is available do:

 guestfish -N help | less

=head2 Remote drives

Access a remote disk using NBD:

 guestfish -a nbd://example.com

=head2 Remote control

 eval "`guestfish --listen`"
 guestfish --remote add-ro disk.img
 guestfish --remote run
 guestfish --remote lvs

=head1 OPTIONS

=over 4

=item B<--help>

Displays general help on options.

=item B<-h>

=item B<--cmd-help>

Lists all available guestfish commands.

=item B<-h> CMD

=item B<--cmd-help> CMD

Displays detailed help on a single command C<cmd>.

=item B<-a> IMAGE

=item B<--add> IMAGE

Add a block device or virtual machine image to the shell.

The format of the disk image is auto-detected.  To override this and
force a particular format use the I<--format=..> option.

Using this flag is mostly equivalent to using the C<add> command,
with C<readonly:true> if the I<--ro> flag was given, and
with C<format:...> if the I<--format=...> flag was given.

=item B<-a> URI

=item B<--add> URI

Add a remote disk.  See L</ADDING REMOTE STORAGE>.

__INCLUDE:blocksize-option.pod__

=item B<-c> URI

=item B<--connect> URI

When used in conjunction with the I<-d> option, this specifies
the libvirt URI to use.  The default is to use the default libvirt
connection.

=item B<--csh>

If using the I<--listen> option and a csh-like shell, use this option.
See section L</REMOTE CONTROL AND CSH> below.

=item B<-d> LIBVIRT-DOMAIN

=item B<--domain> LIBVIRT-DOMAIN

Add disks from the named libvirt domain.  If the I<--ro> option is
also used, then any libvirt domain can be used.  However in write
mode, only libvirt domains which are shut down can be named here.

Domain UUIDs can be used instead of names.

Using this flag is mostly equivalent to using the C<add-domain> command,
with C<readonly:true> if the I<--ro> flag was given, and
with C<format:...> if the I<--format=...> flag was given.

=item B<--echo-keys>

When prompting for keys and passphrases, guestfish 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.

=item B<-f> FILE

=item B<--file> FILE

Read commands from C<FILE>.  To write pure guestfish
scripts, use:

 #!/usr/bin/guestfish -f

=item B<--format=raw|qcow2|..>

=item B<--format>

The default for the I<-a> option is to auto-detect the format of the
disk image.  Using this forces the disk format for I<-a> options which
follow on the command line.  Using I<--format> with no argument
switches back to auto-detection for subsequent I<-a> options.

For example:

 guestfish --format=raw -a disk.img

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

 guestfish --format=raw -a disk.img --format -a another.img

forces raw format (no auto-detection) for F<disk.img> and reverts to
auto-detection for F<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).  See also
L</add>.

=item B<-i>

=item B<--inspector>

Using L<virt-inspector(1)> code, inspect the disks looking for
an operating system and mount filesystems as they would be
mounted on the real virtual machine.

Typical usage is either:

 guestfish -d myguest -i

(for an inactive libvirt domain called I<myguest>), or:

 guestfish --ro -d myguest -i

(for active domains, readonly), or specify the block device directly:

 guestfish --rw -a /dev/Guests/MyGuest -i

Note that the command line syntax changed slightly over older
versions of guestfish.  You can still use the old syntax:

 guestfish [--ro] -i disk.img

 guestfish [--ro] -i libvirt-domain

Using this flag is mostly equivalent to using the C<inspect-os>
command and then using other commands to mount the filesystems that
were found.

__INCLUDE:key-option.pod__

__INCLUDE:keys-from-stdin-option.pod__

=item B<--listen>

Fork into the background and listen for remote commands.  See section
L</REMOTE CONTROL GUESTFISH OVER A SOCKET> below.

=item B<-m> dev[:mountpoint[:options[:fstype]]]

=item B<--mount> dev[:mountpoint[:options[:fstype]]]

Mount the named partition or logical volume on the given mountpoint.

If the mountpoint is omitted, it defaults to F</>.

You have to mount something on F</> before most commands will work.

If any I<-m> or I<--mount> options are given, the guest is
automatically launched.

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 L</list-partitions>,
L</list-filesystems> and L</lvs> commands), or you can use the
L<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 C<ro>
(the latter if the I<--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 C<mount-options> command.

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

=item B<--network>

Enable QEMU user networking in the guest.

=item B<-N> [FILENAME=]TYPE

=item B<--new> [FILENAME=]TYPE

=item B<-N> B<help>

Prepare a fresh disk image formatted as C<TYPE>.  This is an
alternative to the I<-a> option: whereas I<-a> adds an existing disk,
I<-N> creates a preformatted disk with a filesystem and adds it.
See L</PREPARED DISK IMAGES> below.

=item B<-n>

=item B<--no-sync>

Disable autosync.  This is enabled by default.  See the discussion
of autosync in the L<guestfs(3)> manpage.

=item B<--no-dest-paths>

Don’t tab-complete paths on the guest filesystem.  It is useful to be
able to hit the tab key to complete paths on the guest filesystem, but
this causes extra "hidden" guestfs calls to be made, so this option is
here to allow this feature to be disabled.

=item B<--pipe-error>

If writes fail to pipe commands (see L</PIPES> below), then the
command returns an error.

The default (also for historical reasons) is to ignore such errors so
that:

 ><fs> command_with_lots_of_output | head

doesn't give an error.

=item B<--progress-bars>

Enable progress bars, even when guestfish is used non-interactively.

Progress bars are enabled by default when guestfish is used as an
interactive shell.

=item B<--no-progress-bars>

Disable progress bars.

=item B<--remote>

=item B<--remote=>PID

Send remote commands to C<$GUESTFISH_PID> or C<pid>.  See section
L</REMOTE CONTROL GUESTFISH OVER A SOCKET> below.

=item B<-r>

=item B<--ro>

This changes the I<-a>, I<-d> and I<-m> options so that disks are
added and mounts are done read-only.

The option must always be used if the disk image or virtual machine
might be running, and is generally recommended in cases where you
don't need write access to the disk.

Note that prepared disk images created with I<-N> are not affected by
this option.  Also commands like C<add> are not affected - you have to
specify the C<readonly:true> option explicitly if you need it.

See also L</OPENING DISKS FOR READ AND WRITE> below.

=item B<--selinux>

This option is provided for backwards compatibility and does nothing.

=item B<-v>

=item B<--verbose>

Enable very verbose messages.  This is particularly useful if you find
a bug.

=item B<-V>

=item B<--version>

Display the guestfish / libguestfs version number and exit.

=item B<-w>

=item B<--rw>

This changes the I<-a>, I<-d> and I<-m> options so that disks are
added and mounts are done read-write.

See L</OPENING DISKS FOR READ AND WRITE> below.

=item B<-x>

Echo each command before executing it.

=back

=head1 COMMANDS ON COMMAND LINE

Any additional (non-option) arguments are treated as commands to
execute.

Commands to execute should be separated by a colon (C<:>), where the
colon is a separate parameter.  Thus:

 guestfish cmd [args...] : cmd [args...] : cmd [args...] ...

If there are no additional arguments, then we enter a shell, either an
interactive shell with a prompt (if the input is a terminal) or a
non-interactive shell.

In either command line mode or non-interactive shell, the first
command that gives an error causes the whole shell to exit.  In
interactive mode (with a prompt) if a command fails, you can continue
to enter commands.

Note that arguments of the commands will be considered as guestfish
options if they start with a dash (C<->): you can always separate the
guestfish options and the rest of the commands (with their arguments)
using a double dash (C<-->).  For example:

 guestfish -- disk_create overlay.qcow2 qcow2 -1 backingfile:image.img

=head1 USING launch (OR run)

As with L<guestfs(3)>, you must first configure your guest by adding
disks, then launch it, then mount any disks you need, and finally
issue actions/commands.  So the general order of the day is:

=over 4

=item *

add or -a/--add

=item *

launch (aka run)

=item *

mount or -m/--mount

=item *

any other commands

=back

C<run> is a synonym for C<launch>.  You must C<launch> (or C<run>)
your guest before mounting or performing any other commands.

The only exception is that if any of the I<-i>, I<-m>, I<--mount>,
I<-N> or I<--new> options were given then C<run> is done
automatically, simply because guestfish can't perform the action you
asked for without doing this.

=head1 OPENING DISKS FOR READ AND WRITE

The guestfish, L<guestmount(1)> and L<virt-rescue(1)> options I<--ro>
and I<--rw> affect whether the other command line options I<-a>,
I<-c>, I<-d>, I<-i> and I<-m> open disk images read-only or for
writing.

In libguestfs E<le> 1.10, guestfish, guestmount and virt-rescue
defaulted to opening disk images supplied on the command line for
write.  To open a disk image read-only you have to do I<-a image --ro>.

This matters: If you accidentally open a live VM disk image writable
then you will cause irreversible disk corruption.

In a future libguestfs we intend to change the default the other way.
Disk images will be opened read-only.  You will have to either specify
I<guestfish --rw>, I<guestmount --rw>, I<virt-rescue --rw>, or change
the configuration file in order to get write access for disk images
specified by those other command line options.

This version of guestfish, guestmount and virt-rescue has a I<--rw>
option which does nothing (it is already the default).  However it is
highly recommended that you use this option to indicate that you need
write access, and prepare your scripts for the day when this option
will be required for write access.

B<Note:> This does I<not> affect commands like L</add> and L</mount>,
or any other libguestfs program apart from guestfish and guestmount.

=head1 QUOTING

You can quote ordinary parameters using either single or double
quotes.  For example:

 add "file with a space.img"

 rm '/file name'

 rm '/"'

A few commands require a list of strings to be passed.  For these, use
a whitespace-separated list, enclosed in quotes.  Strings containing whitespace
to be passed through must be enclosed in single quotes.  A literal single quote
must be escaped with a backslash.

 vgcreate VG "/dev/sda1 /dev/sdb1"
 command "/bin/echo 'foo      bar'"
 command "/bin/echo \'foo\'"

=head2 ESCAPE SEQUENCES IN DOUBLE QUOTED ARGUMENTS

In double-quoted arguments (only) use backslash to insert special
characters:

=over 4

=item C<\a>

Alert (bell) character.

=item C<\b>

Backspace character.

=item C<\f>

Form feed character.

=item C<\n>

Newline character.

=item C<\r>

Carriage return character.

=item C<\t>

Horizontal tab character.

=item C<\v>

Vertical tab character.

=item C<\">

A literal double quote character.

=item C<\ooo>

A character with octal value I<ooo>.  There must be precisely 3 octal
digits (unlike C).

=item C<\xhh>

A character with hex value I<hh>.  There must be precisely 2 hex
digits.

In the current implementation C<\000> and C<\x00> cannot be used
in strings.

=item C<\\>

A literal backslash character.

=back

=head1 OPTIONAL ARGUMENTS

Some commands take optional arguments.  These arguments appear in this
documentation as C<[argname:..]>.  You can use them as in these
examples:

 add filename

 add filename readonly:true

 add filename format:qcow2 readonly:false

Each optional argument can appear at most once.  All optional
arguments must appear after the required ones.

=head1 NUMBERS

This section applies to all commands which can take integers
as parameters.

=head2 SIZE SUFFIX

When the command takes a parameter measured in bytes, you can use one
of the following suffixes to specify kilobytes, megabytes and larger
sizes:

=over 4

=item B<k> or B<K> or B<KiB>

The size in kilobytes (multiplied by 1024).

=item B<KB>

The size in SI 1000 byte units.

=item B<M> or B<MiB>

The size in megabytes (multiplied by 1048576).

=item B<MB>

The size in SI 1000000 byte units.

=item B<G> or B<GiB>

The size in gigabytes (multiplied by 2**30).

=item B<GB>

The size in SI 10**9 byte units.

=item B<T> or B<TiB>

The size in terabytes (multiplied by 2**40).

=item B<TB>

The size in SI 10**12 byte units.

=item B<P> or B<PiB>

The size in petabytes (multiplied by 2**50).

=item B<PB>

The size in SI 10**15 byte units.

=item B<E> or B<EiB>

The size in exabytes (multiplied by 2**60).

=item B<EB>

The size in SI 10**18 byte units.

=item B<Z> or B<ZiB>

The size in zettabytes (multiplied by 2**70).

=item B<ZB>

The size in SI 10**21 byte units.

=item B<Y> or B<YiB>

The size in yottabytes (multiplied by 2**80).

=item B<YB>

The size in SI 10**24 byte units.

=back

For example:

 truncate-size /file 1G

would truncate the file to 1 gigabyte.

Be careful because a few commands take sizes in kilobytes or megabytes
(eg. the parameter to L</memsize> is specified in megabytes already).
Adding a suffix will probably not do what you expect.

=head2 OCTAL AND HEXADECIMAL NUMBERS

For specifying the radix (base) use the C convention: C<0> to prefix
an octal number or C<0x> to prefix a hexadecimal number.  For example:

 1234      decimal number 1234
 02322     octal number, equivalent to decimal 1234
 0x4d2     hexadecimal number, equivalent to decimal 1234

When using the C<chmod> command, you almost always want to specify an
octal number for the mode, and you must prefix it with C<0> (unlike
the Unix L<chmod(1)> program):

 chmod 0777 /public  # OK
 chmod 777 /public   # WRONG! This is mode 777 decimal = 01411 octal.

Commands that return numbers usually print them in decimal, but
some commands print numbers in other radices (eg. C<umask> prints
the mode in octal, preceded by C<0>).

=head1 WILDCARDS AND GLOBBING

Neither guestfish nor the underlying guestfs API performs
wildcard expansion (globbing) by default.  So for example the
following will not do what you expect:

 rm-rf /home/*

Assuming you don’t have a directory called literally F</home/*>
then the above command will return an error.

To perform wildcard expansion, use the C<glob> command.

 glob rm-rf /home/*

runs C<rm-rf> on each path that matches (ie. potentially running
the command many times), equivalent to:

 rm-rf /home/jim
 rm-rf /home/joe
 rm-rf /home/mary

C<glob> only works on simple guest paths and not on device names.

If you have several parameters, each containing a wildcard, then glob
will perform a Cartesian product.

=head1 COMMENTS

Any line which starts with a I<#> character is treated as a comment
and ignored.  The I<#> can optionally be preceded by whitespace,
but B<not> by a command.  For example:

 # this is a comment
         # this is a comment
 foo # NOT a comment

Blank lines are also ignored.

=head1 RUNNING COMMANDS LOCALLY

Any line which starts with a I<!> character is treated as a command
sent to the local shell (F</bin/sh> or whatever L<system(3)> uses).
For example:

 !mkdir local
 tgz-out /remote local/remote-data.tar.gz

will create a directory C<local> on the host, and then export
the contents of F</remote> on the mounted filesystem to
F<local/remote-data.tar.gz>.  (See C<tgz-out>).

To change the local directory, use the C<lcd> command.  C<!cd> will
have no effect, due to the way that subprocesses work in Unix.

=head2 LOCAL COMMANDS WITH INLINE EXECUTION

If a line starts with I<E<lt>!> then the shell command is executed (as
for I<!>), but subsequently any output (stdout) of the shell command
is parsed and executed as guestfish commands.

Thus you can use shell script to construct arbitrary guestfish
commands which are then parsed by guestfish.

For example it is tedious to create a sequence of files
(eg. F</foo.1> through F</foo.100>) using guestfish commands
alone.  However this is simple if we use a shell script to
create the guestfish commands for us:

 <! for n in `seq 1 100`; do echo write /foo.$n $n; done

or with names like F</foo.001>:

 <! for n in `seq 1 100`; do printf "write /foo.%03d %d\n" $n $n; done

When using guestfish interactively it can be helpful to just run the
shell script first (ie. remove the initial C<E<lt>> character so it is
just an ordinary I<!> local command), see what guestfish commands it
would run, and when you are happy with those prepend the C<E<lt>>
character to run the guestfish commands for real.

=head1 PIPES

Use C<command E<lt>spaceE<gt> | command> to pipe the output of the
first command (a guestfish command) to the second command (any host
command).  For example:

 cat /etc/passwd | awk -F: '$3 == 0 { print }'

(where C<cat> is the guestfish cat command, but C<awk> is the host awk
program).  The above command would list all accounts in the guest
filesystem which have UID 0, ie. root accounts including backdoors.
Other examples:

 hexdump /bin/ls | head
 list-devices | tail -1
 tgz-out / - | tar ztf -

The space before the pipe symbol is required, any space after the pipe
symbol is optional.  Everything after the pipe symbol is just passed
straight to the host shell, so it can contain redirections, globs and
anything else that makes sense on the host side.

To use a literal argument which begins with a pipe symbol, you have
to quote it, eg:

 echo "|"

=head1 HOME DIRECTORIES

If a parameter starts with the character C<~> then the tilde may be
expanded as a home directory path (either C<~> for the current user's
home directory, or C<~user> for another user).

Note that home directory expansion happens for users known I<on the
host>, not in the guest filesystem.

To use a literal argument which begins with a tilde, you have to quote
it, eg:

 echo "~"

=head1 ENCRYPTED DISKS

Libguestfs has some support for Linux guests encrypted according to
the Linux Unified Key Setup (LUKS) standard, which includes nearly all
whole disk encryption systems used by modern Linux guests, and Windows
BitLocker.

Identify encrypted block devices and partitions using L</vfs-type>:

 ><fs> vfs-type /dev/sda2
 crypto_LUKS

or:

 ><fs> vfs-type /dev/sda2
 BitLocker

Then open those devices using L</cryptsetup-open>.
This creates a device-mapper device called F</dev/mapper/name>.

 ><fs> cryptsetup-open /dev/sda2 name
 Enter key or passphrase ("key"): <enter the passphrase>

For Linux guests you have to tell LVM to scan for volume groups on the
newly created mapper device:

 vgscan
 vg-activate-all true

The filesystems or logical volumes can now be mounted in the usual way.

Before closing an encrypted device you must unmount any logical
volumes on it and deactivate the volume groups by calling
C<vg-activate false VG> on each one.  Then you can close the mapper
device:

 vg-activate false /dev/VG
 cryptsetup-close /dev/mapper/name

=head1 WINDOWS PATHS

If a path is prefixed with C<win:> then you can use Windows-style
drive letters and paths (with some limitations).  The following
commands are equivalent:

 file /WINDOWS/system32/config/system.LOG

 file win:\windows\system32\config\system.log

 file WIN:C:\Windows\SYSTEM32\CONFIG\SYSTEM.LOG

The parameter is rewritten "behind the scenes" by looking up the
position where the drive is mounted, prepending that to the path,
changing all backslash characters to forward slash, then resolving the
result using L</case-sensitive-path>.  For example if the E: drive
was mounted on F</e> then the parameter might be rewritten like this:

 win:e:\foo\bar => /e/FOO/bar

This only works in argument positions that expect a path.

=head1 UPLOADING AND DOWNLOADING FILES

For commands such as C<upload>, C<download>, C<tar-in>, C<tar-out> and
others which upload from or download to a local file, you can use the
special filename C<-> to mean "from stdin" or "to stdout".  For example:

 upload - /foo

reads stdin and creates from that a file F</foo> in the disk image,
and:

 tar-out /etc - | tar tf -

writes the tarball to stdout and then pipes that into the external
"tar" command (see L</PIPES>).

When using C<-> to read from stdin, the input is read up to the end of
stdin.  You can also use a special "heredoc"-like syntax to read up to
some arbitrary end marker:

 upload -<<END /foo
 input line 1
 input line 2
 input line 3
 END

Any string of characters can be used instead of C<END>.  The end
marker must appear on a line of its own, without any preceding or
following characters (not even spaces).

Note that the C<-E<lt>E<lt>> syntax only applies to parameters used to
upload local files (so-called "FileIn" parameters in the generator).

=head1 EXIT ON ERROR BEHAVIOUR

By default, guestfish will ignore any errors when in interactive mode
(ie. taking commands from a human over a tty), and will exit on the
first error in non-interactive mode (scripts, commands given on the
command line).

If you prefix a command with a I<-> character, then that command will
not cause guestfish to exit, even if that (one) command returns an
error.

=head1 REMOTE CONTROL GUESTFISH OVER A SOCKET

Guestfish can be remote-controlled over a socket.  This is useful
particularly in shell scripts where you want to make several different
changes to a filesystem, but you don't want the overhead of starting
up a guestfish process each time.

Start a guestfish server process using:

 eval "`guestfish --listen`"

and then send it commands by doing:

 guestfish --remote cmd [...]

To cause the server to exit, send it the exit command:

 guestfish --remote exit

Note that the server will normally exit if there is an error in a
command.  You can change this in the usual way.  See section
L</EXIT ON ERROR BEHAVIOUR>.

=head2 CONTROLLING MULTIPLE GUESTFISH PROCESSES

The C<eval> statement sets the environment variable C<$GUESTFISH_PID>,
which is how the I<--remote> option knows where to send the commands.
You can have several guestfish listener processes running using:

 eval "`guestfish --listen`"
 pid1=$GUESTFISH_PID
 eval "`guestfish --listen`"
 pid2=$GUESTFISH_PID
 ...
 guestfish --remote=$pid1 cmd
 guestfish --remote=$pid2 cmd

=head2 REMOTE CONTROL AND CSH

When using csh-like shells (csh, tcsh etc) you have to add the
I<--csh> option:

 eval "`guestfish --listen --csh`"

=head2 REMOTE CONTROL DETAILS

Remote control happens over a Unix domain socket called
F</tmp/.guestfish-$UID/socket-$PID>, where C<$UID> is the effective
user ID of the process, and C<$PID> is the process ID of the server.

Guestfish client and server versions must match exactly.

Older versions of guestfish were vulnerable to CVE-2013-4419 (see
L<guestfs(3)/CVE-2013-4419>).  This is fixed in the current version.

=head2 USING REMOTE CONTROL ROBUSTLY FROM SHELL SCRIPTS

From Bash, you can use the following code which creates a guestfish
instance, correctly quotes the command line, handles failure to start,
and cleans up guestfish when the script exits:

 #!/bin/bash -
 
 set -e
 
 guestfish[0]="guestfish"
 guestfish[1]="--listen"
 guestfish[2]="--ro"
 guestfish[3]="-a"
 guestfish[4]="disk.img"
 
 GUESTFISH_PID=
 eval $("${guestfish[@]}")
 if [ -z "$GUESTFISH_PID" ]; then
     echo "error: guestfish didn't start up, see error messages above"
     exit 1
 fi
 
 cleanup_guestfish ()
 {
     guestfish --remote -- exit >/dev/null 2>&1 ||:
 }
 trap cleanup_guestfish EXIT ERR
 
 guestfish --remote -- run
 
 # ...

=head2 REMOTE CONTROL DOES NOT WORK WITH I<-a> ETC. OPTIONS

Options such as I<-a>, I<--add>, I<-N>, I<--new> etc don’t interact
properly with remote support.  They are processed locally, and not
sent through to the remote guestfish.  In particular this won't do
what you expect:

 guestfish --remote --add disk.img

Don’t use these options.  Use the equivalent commands instead, eg:

 guestfish --remote add-drive disk.img

or:

 guestfish --remote
 ><fs> add disk.img

=head2 REMOTE CONTROL RUN COMMAND HANGING

Using the C<run> (or C<launch>) command remotely in a command
substitution context hangs, ie. don't do (note the backquotes):

 a=`guestfish --remote run`

Since the C<run> command produces no output on stdout, this is not
useful anyway.  For further information see
L<https://bugzilla.redhat.com/show_bug.cgi?id=592910>.

=head1 PREPARED DISK IMAGES

Use the I<-N [filename=]type> or I<--new [filename=]type> parameter to
select one of a set of preformatted disk images that guestfish can
make for you to save typing.  This is particularly useful for testing
purposes.  This option is used instead of the I<-a> option, and like
I<-a> can appear multiple times (and can be mixed with I<-a>).

The new disk is called F<test1.img> for the first I<-N>, F<test2.img>
for the second and so on.  Existing files in the current directory are
I<overwritten>.  You can use a different filename by specifying
C<filename=> before the type (see examples below).

The type briefly describes how the disk should be sized, partitioned,
how filesystem(s) should be created, and how content should be added.
Optionally the type can be followed by extra parameters, separated by
C<:> (colon) characters.  For example, I<-N fs> creates a default 1G,
sparsely-allocated disk, containing a single partition, with the
partition formatted as ext2.  I<-N fs:ext4:2G> is the same, but for an
ext4 filesystem on a 2GB disk instead.

Note that the prepared filesystem is not mounted.  You would usually
have to use the C<mount /dev/sda1 /> command or add the
I<-m /dev/sda1> option.

If any I<-N> or I<--new> options are given, the libguestfs appliance
is automatically launched.

=head2 EXAMPLES

Create a 1G disk with an ext4-formatted partition, called
F<test1.img> in the current directory:

 guestfish -N fs:ext4

Create a 32MB disk with a VFAT-formatted partition, and mount it:

 guestfish -N fs:vfat:32M -m /dev/sda1

Create a blank 200MB disk:

 guestfish -N disk:200M

Create a blank 200MB disk called F<blankdisk.img> (instead of
F<test1.img>):

 guestfish -N blankdisk.img=disk:200M

__INCLUDE:guestfish-prepopts.pod__

=head1 ADDING REMOTE STORAGE

I<For API-level documentation on this topic, see
L<guestfs(3)/guestfs_add_drive_opts> and
L<guestfs(3)/REMOTE STORAGE>>.

On the command line, you can use the I<-a> option to add network
block devices using a URI-style format, for example:

 guestfish -a nbd://example.com

URIs I<cannot> be used with the L</add> command.  The equivalent
command using the API directly is:

 ><fs> add /disk.img protocol:nbd server:tcp:example.com

The possible I<-a URI> formats are described below.

=head2 B<-a disk.img>

=head2 B<-a file:///path/to/disk.img>

Add the local disk image (or device) called F<disk.img>.

=head2 B<-a nbd://example.com[:port]>

=head2 B<-a nbd://example.com[:port]/exportname>

=head2 B<-a nbd://?socket=/socket>

=head2 B<-a nbd:///exportname?socket=/socket>

Add a disk located on Network Block Device (nbd) storage.

The I<exportname> part of the URI specifies an NBD export name, but
is usually left empty.

The optional I<?socket> parameter can be used to specify a Unix domain
socket that we talk to the NBD server over.  Note that you cannot mix
server name (ie. TCP/IP) and socket path.

The equivalent API command would be (no export name):

 ><fs> add "" protocol:nbd server:[tcp:example.com|unix:/socket]

=head2 B<-a rbd:///pool/disk>

=head2 B<-a rbd://example.com[:port]/pool/disk>

Add a disk image located on a Ceph (RBD/librbd) storage volume.

Although libguestfs and Ceph supports multiple servers, only a single
server can be specified when using this URI syntax.

The equivalent API command would be:

 ><fs> add pool/disk protocol:rbd server:tcp:example.com:port

Note that the URIs follow the syntax of
L<RFC 3986|https://tools.ietf.org/html/rfc3986>: in particular, there
are restrictions on the allowed characters for the various components
of the URI.  Characters such as C<:>, C<@>, and C</> B<must> be
percent-encoded:

 $ guestfish -a rbd://user:pass%40word@example.com[:port]/pool/disk

In this case, the password is C<pass@word>.

=head1 PROGRESS BARS

Some (not all) long-running commands send progress notification
messages as they are running.  Guestfish turns these messages into
progress bars.

When a command that supports progress bars takes longer than two
seconds to run, and if progress bars are enabled, then you will see
one appearing below the command:

 ><fs> copy-size /large-file /another-file 2048M
 / 10% [#####-----------------------------------------] 00:30

The spinner on the left hand side moves round once for every progress
notification received from the backend.  This is a (reasonably) golden
assurance that the command is "doing something" even if the progress
bar is not moving, because the command is able to send the progress
notifications.  When the bar reaches 100% and the command finishes,
the spinner disappears.

Progress bars are enabled by default when guestfish is used
interactively.  You can enable them even for non-interactive modes
using I<--progress-bars>, and you can disable them completely using
I<--no-progress-bars>.

=head1 PROMPT

You can change or add colours to the default prompt
(C<E<gt>E<lt>fsE<gt>>) by setting the C<GUESTFISH_PS1> environment
variable.  A second string (C<GUESTFISH_OUTPUT>) is printed after the
command has been entered and before the output, allowing you to
control the colour of the output.  A third string (C<GUESTFISH_INIT>)
is printed before the welcome message, allowing you to control the
colour of that message.  A fourth string (C<GUESTFISH_RESTORE>) is
printed before guestfish exits.

A simple prompt can be set by setting C<GUESTFISH_PS1> to an alternate
string:

 $ GUESTFISH_PS1='(type a command) '
 $ export GUESTFISH_PS1
 $ guestfish
 [...]
 (type a command) ▂

You can also use special escape sequences, as described in the table
below:

=over 4

=item \\

A literal backslash character.

=item \[

=item \]

(These should only be used in C<GUESTFISH_PS1>.)

Place non-printing characters (eg. terminal control codes for colours)
between C<\[...\]>.  What this does it to tell the L<readline(3)>
library that it should treat this subsequence as zero-width, so that
command-line redisplay, editing etc works.

=item \a

A bell character.

=item \e

An ASCII ESC (escape) character.

=item \n

A newline.

=item \r

A carriage return.

=item \NNN

The ASCII character whose code is the octal value NNN.

=item \xNN

The ASCII character whose code is the hex value NN.

=back

=head2 EXAMPLES OF PROMPTS

Note that these examples require a terminal that supports ANSI escape codes.

=over 4

=item *

 GUESTFISH_PS1='\[\e[1;30m\]><fs>\[\e[0;30m\] '

A bold black version of the ordinary prompt.

=item *

 GUESTFISH_PS1='\[\e[1;32m\]><fs>\[\e[0;31m\] '
 GUESTFISH_OUTPUT='\e[0m'
 GUESTFISH_RESTORE="$GUESTFISH_OUTPUT"
 GUESTFISH_INIT='\e[1;34m'

Blue welcome text, green prompt, red commands, black command
output.

=back

=head1 WINDOWS 8

Windows 8 "fast startup" can prevent guestfish from mounting NTFS
partitions.  See
L<guestfs(3)/WINDOWS HIBERNATION AND WINDOWS 8 FAST STARTUP>.

=head1 GUESTFISH COMMANDS

The commands in this section are guestfish convenience commands, in
other words, they are not part of the L<guestfs(3)> API.

=head2 help

 help
 help cmd
 help -l|--list

Without any parameter, this provides general help.

With a C<cmd> parameter, this displays detailed help for that command.

With I<-l> or I<--list>, this list all commands.

=head2 exit

=head2 quit

This exits guestfish.  You can also use C<^D> key.

__INCLUDE:guestfish-commands.pod__

=head1 COMMANDS

__INCLUDE:guestfish-actions.pod__

=head1 EXIT STATUS

guestfish returns 0 if the commands completed without error, or
1 if there was an error.

=head1 ENVIRONMENT VARIABLES

=over 4

=item EDITOR

The C<edit> command uses C<$EDITOR> as the editor.  If not
set, it uses C<vi>.

=item GUESTFISH_DISPLAY_IMAGE

The C<display> command uses C<$GUESTFISH_DISPLAY_IMAGE> to
display images.  If not set, it uses L<display(1)>.

=item GUESTFISH_INIT

Printed when guestfish starts.  See L</PROMPT>.

=item GUESTFISH_OUTPUT

Printed before guestfish output.  See L</PROMPT>.

=item GUESTFISH_PID

Used with the I<--remote> option to specify the remote guestfish
process to control.  See section
L</REMOTE CONTROL GUESTFISH OVER A SOCKET>.

=item GUESTFISH_PS1

Set the command prompt.  See L</PROMPT>.

=item GUESTFISH_RESTORE

Printed before guestfish exits.  See L</PROMPT>.

=item HEXEDITOR

The L</hexedit> command uses C<$HEXEDITOR> as the external hex
editor.  If not specified, the external L<hexedit(1)> program
is used.

=item HOME

If compiled with GNU readline support, various files in the
home directory can be used.  See L</FILES>.

=item LIBGUESTFS_APPEND

Pass additional options to the guest kernel.

=item LIBGUESTFS_ATTACH_METHOD

This is the old way to set C<LIBGUESTFS_BACKEND>.

=item LIBGUESTFS_BACKEND

Choose the default way to create the appliance.  See
L<guestfs(3)/guestfs_set_backend>.

=item LIBGUESTFS_BACKEND_SETTINGS

A colon-separated list of backend-specific settings.
See L<guestfs(3)/BACKEND>, L<guestfs(3)/BACKEND SETTINGS>.

=item LIBGUESTFS_CACHEDIR

The location where libguestfs will cache its appliance, when
using a supermin appliance.  The appliance is cached and shared
between all handles which have the same effective user ID.

If C<LIBGUESTFS_CACHEDIR> is not set, then C<TMPDIR> is used.  If
C<TMPDIR> is not set, then F</var/tmp> is used.

See also L</LIBGUESTFS_TMPDIR>, L</set-cachedir>.

=item LIBGUESTFS_DEBUG

Set C<LIBGUESTFS_DEBUG=1> to enable verbose messages.  This has the
same effect as using the B<-v> option.

=item LIBGUESTFS_HV

Set the default hypervisor (usually qemu) binary that libguestfs uses.
If not set, then the qemu which was found at compile time by the
configure script is used.

=item LIBGUESTFS_MEMSIZE

Set the memory allocated to the qemu process, in megabytes.  For
example:

 LIBGUESTFS_MEMSIZE=700

=item LIBGUESTFS_PATH

Set the path that guestfish uses to search for kernel and initrd.img.
See the discussion of paths in L<guestfs(3)>.

=item LIBGUESTFS_QEMU

This is the old way to set C<LIBGUESTFS_HV>.

=item LIBGUESTFS_TMPDIR

The location where libguestfs will store temporary files used
by each handle.

If C<LIBGUESTFS_TMPDIR> is not set, then C<TMPDIR> is used.  If
C<TMPDIR> is not set, then F</tmp> is used.

See also L</LIBGUESTFS_CACHEDIR>, L</set-tmpdir>.

=item LIBGUESTFS_TRACE

Set C<LIBGUESTFS_TRACE=1> to enable command traces.

=item PAGER

The C<more> command uses C<$PAGER> as the pager.  If not
set, it uses C<more>.

=item PATH

Libguestfs and guestfish may run some external programs, and rely on
C<$PATH> being set to a reasonable value.  If using the libvirt
backend, libvirt will not work at all unless C<$PATH> contains
the path of qemu/KVM.

=item SUPERMIN_KERNEL

=item SUPERMIN_KERNEL_VERSION

=item SUPERMIN_MODULES

These three environment variables allow the kernel that libguestfs
uses in the appliance to be selected.  If C<$SUPERMIN_KERNEL> is not
set, then the most recent host kernel is chosen.  For more information
about kernel selection, see L<supermin(1)>.

=item TMPDIR

See L</LIBGUESTFS_CACHEDIR>, L</LIBGUESTFS_TMPDIR>.

=item XDG_RUNTIME_DIR

This directory represents a user-specific directory for storing
non-essential runtime files.

If it is set, then is used to store temporary sockets.  Otherwise,
F</tmp> is used.

See also L</get-sockdir>,
L<http://www.freedesktop.org/wiki/Specifications/basedir-spec/>.

=back

=head1 FILES

=over 4

=item $XDG_CONFIG_HOME/libguestfs/libguestfs-tools.conf

=item $HOME/.libguestfs-tools.rc

=item $XDG_CONFIG_DIRS/libguestfs/libguestfs-tools.conf

=item /etc/libguestfs-tools.conf

This configuration file controls the default read-only or read-write
mode (I<--ro> or I<--rw>).

See L<libguestfs-tools.conf(5)>.

=item $HOME/.guestfish

If compiled with GNU readline support, then the command history
is saved in this file.

=item $HOME/.inputrc

=item /etc/inputrc

If compiled with GNU readline support, then these files can be used to
configure readline.  For further information, please see
L<readline(3)/INITIALIZATION FILE>.

To write rules which only apply to guestfish, use:

 $if guestfish
 ...
 $endif

Variables that you can set in inputrc that change the behaviour
of guestfish in useful ways include:

=over 4

=item completion-ignore-case (default: on)

By default, guestfish will ignore case when tab-completing
paths on the disk.  Use:

 set completion-ignore-case off

to make guestfish case sensitive.

=back

=item test1.img

=item test2.img (etc)

When using the I<-N> or I<--new> option, the prepared disk or
filesystem will be created in the file F<test1.img> in the current
directory.  The second use of I<-N> will use F<test2.img> and so on.
Any existing file with the same name will be overwritten.  You can use
a different filename by using the C<filename=> prefix.

=back

=head1 SEE ALSO

L<guestfs(3)>,
L<http://libguestfs.org/>,
L<virt-alignment-scan(1)>,
L<virt-builder(1)>,
L<virt-builder-repository(1)>,
L<virt-cat(1)>,
L<virt-copy-in(1)>,
L<virt-copy-out(1)>,
L<virt-customize(1)>,
L<virt-df(1)>,
L<virt-diff(1)>,
L<virt-edit(1)>,
L<virt-filesystems(1)>,
L<virt-inspector(1)>,
L<virt-list-filesystems(1)>,
L<virt-list-partitions(1)>,
L<virt-log(1)>,
L<virt-ls(1)>,
L<virt-make-fs(1)>,
L<virt-p2v(1)>,
L<virt-rescue(1)>,
L<virt-resize(1)>,
L<virt-sparsify(1)>,
L<virt-sysprep(1)>,
L<virt-tail(1)>,
L<virt-tar(1)>,
L<virt-tar-in(1)>,
L<virt-tar-out(1)>,
L<virt-v2v(1)>,
L<virt-win-reg(1)>,
L<libguestfs-tools.conf(5)>,
L<display(1)>,
L<hexedit(1)>,
L<supermin(1)>.

=head1 AUTHORS

Richard W.M. Jones (C<rjones at redhat dot com>)

=head1 COPYRIGHT

Copyright (C) 2009-2020 Red Hat Inc.