Subsequent elements are parameters. The list must be
non-empty (ie. must contain a program name).
+The return value is anything printed to I<stdout> by
+the command.
+
+If the command returns a non-zero exit status, then
+this function returns an error message. The error message
+string is the content of I<stderr> from the command.
+
The C<$PATH> environment variable will contain at least
C</usr/bin> and C</bin>. If you require a program from
another location, you should provide the full path in the
all filesystems that are needed are mounted at the right
locations.
+Because of the message protocol, there is a transfer limit
+of somewhere between 2MB and 4MB. To transfer large files you should use
+FTP.
+
=head2 command-lines
command-lines 'arguments ...'
This is the same as C<command>, but splits the
result into a list of lines.
+Because of the message protocol, there is a transfer limit
+of somewhere between 2MB and 4MB. To transfer large files you should use
+FTP.
+
=head2 config
config qemuparam qemuvalue
C<value> can be NULL.
+=head2 cp
+
+ cp src dest
+
+This copies a file from C<src> to C<dest> where C<dest> is
+either a destination filename or destination directory.
+
+=head2 cp-a
+
+ cp-a src dest
+
+This copies a file or directory from C<src> to C<dest>
+recursively using the C<cp -a> command.
+
=head2 debug
debug subcmd 'extraargs ...'
to look at the file C<daemon/debug.c> in the libguestfs source
to find out what you can do.
+=head2 dmesg
+
+ dmesg
+
+This returns the kernel messages (C<dmesg> output) from
+the guest kernel. This is sometimes useful for extended
+debugging of problems.
+
+Another way to get the same information is to enable
+verbose messages with C<set-verbose> or by setting
+the environment variable C<LIBGUESTFS_DEBUG=1> before
+running the program.
+
=head2 download
download remotefilename (filename|-)
Use C<-> instead of a filename to read/write from stdin/stdout.
+=head2 drop-caches
+
+ drop-caches whattodrop
+
+This instructs the guest kernel to drop its page cache,
+and/or dentries and inode caches. The parameter C<whattodrop>
+tells the kernel what precisely to drop, see
+L<http://linux-mm.org/Drop_Caches>
+
+Setting C<whattodrop> to 3 should drop everything.
+
+This automatically calls L<sync(2)> before the operation,
+so that the maximum guest memory is freed.
+
+=head2 e2fsck-f
+
+ e2fsck-f device
+
+This runs C<e2fsck -p -f device>, ie. runs the ext2/ext3
+filesystem checker on C<device>, noninteractively (C<-p>),
+even if the filesystem appears to be clean (C<-f>).
+
+This command is only needed because of C<resize2fs>
+(q.v.). Normally you should use C<fsck>.
+
+=head2 equal
+
+ equal file1 file2
+
+This compares the two files C<file1> and C<file2> and returns
+true if their content is exactly equal, or false otherwise.
+
+The external L<cmp(1)> program is used for the comparison.
+
=head2 exists
exists path
particular that the filename is not prepended to the output
(the C<-b> option).
+=head2 find
+
+ find directory
+
+This command lists out all files and directories, recursively,
+starting at C<directory>. It is essentially equivalent to
+running the shell command C<find directory -print> but some
+post-processing happens on the output, described below.
+
+This returns a list of strings I<without any prefix>. Thus
+if the directory structure was:
+
+ /tmp/a
+ /tmp/b
+ /tmp/c/d
+
+then the returned list from C<find> C</tmp> would be
+4 elements:
+
+ a
+ b
+ c
+ c/d
+
+If C<directory> is not a directory, then this command returns
+an error.
+
+The returned list is sorted.
+
+=head2 fsck
+
+ fsck fstype device
+
+This runs the filesystem checker (fsck) on C<device> which
+should have filesystem type C<fstype>.
+
+The returned integer is the status. See L<fsck(8)> for the
+list of status codes from C<fsck>.
+
+Notes:
+
+=over 4
+
+=item *
+
+Multiple status codes can be summed together.
+
+=item *
+
+A non-zero return code can mean "success", for example if
+errors have been corrected on the filesystem.
+
+=item *
+
+Checking or repairing NTFS volumes is not supported
+(by linux-ntfs).
+
+=back
+
+This command is entirely equivalent to running C<fsck -a -t fstype device>.
+
+=head2 get-append
+
+ get-append
+
+Return the additional kernel options which are added to the
+guest kernel command line.
+
+If C<NULL> then no options are added.
+
=head2 get-autosync
get-autosync
Get the autosync flag.
+=head2 get-e2label
+
+ get-e2label device
+
+This returns the ext2/3/4 filesystem label of the filesystem on
+C<device>.
+
+=head2 get-e2uuid
+
+ get-e2uuid device
+
+This returns the ext2/3/4 filesystem UUID of the filesystem on
+C<device>.
+
=head2 get-path
get-path
This returns the verbose messages flag.
+=head2 grub-install
+
+ grub-install root device
+
+This command installs GRUB (the Grand Unified Bootloader) on
+C<device>, with the root directory being C<root>.
+
+=head2 hexdump
+
+ hexdump path
+
+This runs C<hexdump -C> on the given C<path>. The result is
+the human-readable, canonical hex dump of the file.
+
+Because of the message protocol, there is a transfer limit
+of somewhere between 2MB and 4MB. To transfer large files you should use
+FTP.
+
=head2 is-busy
is-busy
You can also remove all LVs in a volume group by specifying
the VG name, C</dev/VG>.
+=head2 lvresize
+
+ lvresize device mbytes
+
+This resizes (expands or shrinks) an existing LVM logical
+volume to C<mbytes>. When reducing, data in the reduced part
+is lost.
+
=head2 lvs
lvs
mkfs fstype device
This creates a filesystem on C<device> (usually a partition
-of LVM logical volume). The filesystem type is C<fstype>, for
+or LVM logical volume). The filesystem type is C<fstype>, for
example C<ext3>.
=head2 mount
Some internal mounts are not shown.
+=head2 mv
+
+ mv src dest
+
+This moves a file from C<src> to C<dest> where C<dest> is
+either a destination filename or destination directory.
+
+=head2 ping-daemon
+
+ ping-daemon
+
+This is a test probe into the guestfs daemon running inside
+the qemu subprocess. Calling this function checks that the
+daemon responds to the ping message, without affecting the daemon
+or attached block device(s) in any other way.
+
=head2 pvcreate
pvcreate device
wipe physical volumes that contain any volume groups, so you have
to remove those first.
+=head2 pvresize
+
+ pvresize device
+
+This resizes (expands or shrinks) an existing LVM physical
+volume to match the new size of the underlying device.
+
=head2 pvs
pvs
as end of line). For those you need to use the C<read-file>
function which has a more complex interface.
+=head2 resize2fs
+
+ resize2fs device
+
+This resizes an ext2 or ext3 filesystem to match the size of
+the underlying device.
+
+I<Note:> It is sometimes required that you run C<e2fsck-f>
+on the C<device> before calling this command. For unknown reasons
+C<resize2fs> sometimes gives an error about this and sometimes not.
+In any case, it is always safe to call C<e2fsck-f> before
+calling this function.
+
=head2 rm
rm path
Remove the single directory C<path>.
+=head2 set-append | append
+
+ set-append append
+
+This function is used to add additional options to the
+guest kernel command line.
+
+The default is C<NULL> unless overridden by setting
+C<LIBGUESTFS_APPEND> environment variable.
+
+Setting C<append> to C<NULL> means I<no> additional options
+are passed (libguestfs always adds a few of its own).
+
=head2 set-autosync | autosync
set-autosync true|false
If C<autosync> is true, this enables autosync. Libguestfs will make a
-best effort attempt to run C<sync> when the handle is closed
+best effort attempt to run C<umount-all> followed by
+C<sync> when the handle is closed
(also if the program exits without closing handles).
+This is disabled by default (except in guestfish where it is
+enabled by default).
+
+=head2 set-e2label
+
+ set-e2label device label
+
+This sets the ext2/3/4 filesystem label of the filesystem on
+C<device> to C<label>. Filesystem labels are limited to
+16 characters.
+
+You can use either C<tune2fs-l> or C<get-e2label>
+to return the existing label on a filesystem.
+
+=head2 set-e2uuid
+
+ set-e2uuid device uuid
+
+This sets the ext2/3/4 filesystem UUID of the filesystem on
+C<device> to C<uuid>. The format of the UUID and alternatives
+such as C<clear>, C<random> and C<time> are described in the
+L<tune2fs(8)> manpage.
+
+You can use either C<tune2fs-l> or C<get-e2uuid>
+to return the existing UUID of a filesystem.
+
=head2 set-path | path
set-path path
The default is C<$libdir/guestfs> unless overridden by setting
C<LIBGUESTFS_PATH> environment variable.
-The string C<path> is stashed in the libguestfs handle, so the caller
-must make sure it remains valid for the lifetime of the handle.
-
Setting C<path> to C<NULL> restores the default path.
=head2 set-qemu | qemu
You can also override this by setting the C<LIBGUESTFS_QEMU>
environment variable.
-The string C<qemu> is stashed in the libguestfs handle, so the caller
-must make sure it remains valid for the lifetime of the handle.
-
Setting C<qemu> to C<NULL> restores the default qemu binary.
=head2 set-verbose | verbose
pass C<lines> as a single element list, when the single element being
the string C<,> (comma).
+See also: C<sfdisk-l>, C<sfdisk-N>
+
+B<This command is dangerous. Without careful use you
+can easily destroy all your data>.
+
+=head2 sfdisk-N
+
+ sfdisk-N device n cyls heads sectors line
+
+This runs L<sfdisk(8)> option to modify just the single
+partition C<n> (note: C<n> counts from 1).
+
+For other parameters, see C<sfdisk>. You should usually
+pass C<0> for the cyls/heads/sectors parameters.
+
B<This command is dangerous. Without careful use you
can easily destroy all your data>.
+=head2 sfdisk-disk-geometry
+
+ sfdisk-disk-geometry device
+
+This displays the disk geometry of C<device> read from the
+partition table. Especially in the case where the underlying
+block device has been resized, this can be different from the
+kernel's idea of the geometry (see C<sfdisk-kernel-geometry>).
+
+The result is in human-readable format, and not designed to
+be parsed.
+
+=head2 sfdisk-kernel-geometry
+
+ sfdisk-kernel-geometry device
+
+This displays the kernel's idea of the geometry of C<device>.
+
+The result is in human-readable format, and not designed to
+be parsed.
+
+=head2 sfdisk-l
+
+ sfdisk-l device
+
+This displays the partition table on C<device>, in the
+human-readable output of the L<sfdisk(8)> command. It is
+not intended to be parsed.
+
=head2 stat
stat path
This is the same as the C<statvfs(2)> system call.
+=head2 strings
+
+ strings path
+
+This runs the L<strings(1)> command on a file and returns
+the list of printable strings found.
+
+Because of the message protocol, there is a transfer limit
+of somewhere between 2MB and 4MB. To transfer large files you should use
+FTP.
+
+=head2 strings-e
+
+ strings-e encoding path
+
+This is like the C<strings> command, but allows you to
+specify the encoding.
+
+See the L<strings(1)> manpage for the full list of encodings.
+
+Commonly useful encodings are C<l> (lower case L) which will
+show strings inside Windows/x86 files.
+
+The returned strings are transcoded to UTF-8.
+
+Because of the message protocol, there is a transfer limit
+of somewhere between 2MB and 4MB. To transfer large files you should use
+FTP.
+
=head2 sync
sync
Use C<-> instead of a filename to read/write from stdin/stdout.
+=head2 vg-activate
+
+ vg-activate true|false 'volgroups ...'
+
+This command activates or (if C<activate> is false) deactivates
+all logical volumes in the listed volume groups C<volgroups>.
+If activated, then they are made known to the
+kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
+then those devices disappear.
+
+This command is the same as running C<vgchange -a y|n volgroups...>
+
+Note that if C<volgroups> is an empty list then B<all> volume groups
+are activated or deactivated.
+
+=head2 vg-activate-all
+
+ vg-activate-all true|false
+
+This command activates or (if C<activate> is false) deactivates
+all logical volumes in all volume groups.
+If activated, then they are made known to the
+kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
+then those devices disappear.
+
+This command is the same as running C<vgchange -a y|n>
+
=head2 vgcreate
vgcreate volgroup 'physvols ...'
then the length is calculated using C<strlen> (so in this case
the content cannot contain embedded ASCII NULs).
+I<NB.> Owing to a bug, writing content containing ASCII NUL
+characters does I<not> work, even if the length is specified.
+We hope to resolve this bug in a future version. In the meantime
+use C<upload>.
+
Because of the message protocol, there is a transfer limit
of somewhere between 2MB and 4MB. To transfer large files you should use
FTP.
+=head2 zero
+
+ zero device
+
+This command writes zeroes over the first few blocks of C<device>.
+
+How many blocks are zeroed isn't specified (but it's I<not> enough
+to securely wipe the device). It should be sufficient to remove
+any partition tables, filesystem superblocks and so on.
+
+=head2 zerofree
+
+ zerofree device
+
+This runs the I<zerofree> program on C<device>. This program
+claims to zero unused inodes and disk blocks on an ext2/3
+filesystem, thus making it possible to compress the filesystem
+more effectively.
+
+You should B<not> run this program if the filesystem is
+mounted.
+
+It is possible that using this program can damage the filesystem
+or data on the filesystem.
+
git.annexia.org / libguestfs.git / blobdiff