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7 # This library is free software; you can redistribute it and/or
8 # modify it under the terms of the GNU Lesser General Public
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12 # This library is distributed in the hope that it will be useful,
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14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 # Lesser General Public License for more details.
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25 Sys::Guestfs - Perl bindings for libguestfs
31 my $h = Sys::Guestfs->new ();
32 $h->add_drive ('guest.img');
35 $h->mount ('/dev/sda1', '/');
41 The C<Sys::Guestfs> module provides a Perl XS binding to the
42 libguestfs API for examining and modifying virtual machine
45 Amongst the things this is good for: making batch configuration
46 changes to guests, getting disk used/free statistics (see also:
47 virt-df), migrating between virtualization systems (see also:
48 virt-p2v), performing partial backups, performing partial guest
49 clones, cloning guests and changing registry/UUID/hostname info, and
52 Libguestfs uses Linux kernel and qemu code, and can access any type of
53 guest filesystem that Linux and qemu can, including but not limited
54 to: ext2/3/4, btrfs, FAT and NTFS, LVM, many different disk partition
55 schemes, qcow, qcow2, vmdk.
57 Libguestfs provides ways to enumerate guest storage (eg. partitions,
58 LVs, what filesystem is in each LV, etc.). It can also run commands
59 in the context of the guest. Also you can access filesystems over FTP.
63 All errors turn into calls to C<croak> (see L<Carp(3)>).
77 XSLoader::load ('Sys::Guestfs');
79 =item $h = Sys::Guestfs->new ();
81 Create a new guestfs handle.
87 my $class = ref ($proto) || $proto;
89 my $self = Sys::Guestfs::_create ();
94 =item $h->add_cdrom ($filename);
96 This function adds a virtual CD-ROM disk image to the guest.
98 This is equivalent to the qemu parameter C<-cdrom filename>.
100 =item $h->add_drive ($filename);
102 This function adds a virtual machine disk image C<filename> to the
103 guest. The first time you call this function, the disk appears as IDE
104 disk 0 (C</dev/sda>) in the guest, the second time as C</dev/sdb>, and
107 You don't necessarily need to be root when using libguestfs. However
108 you obviously do need sufficient permissions to access the filename
109 for whatever operations you want to perform (ie. read access if you
110 just want to read the image or write access if you want to modify the
113 This is equivalent to the qemu parameter C<-drive file=filename>.
115 =item $h->aug_close ();
117 Close the current Augeas handle and free up any resources
118 used by it. After calling this, you have to call
119 C<$h-E<gt>aug_init> again before you can use any other
122 =item ($nrnodes, $created) = $h->aug_defnode ($name, $expr, $val);
124 Defines a variable C<name> whose value is the result of
127 If C<expr> evaluates to an empty nodeset, a node is created,
128 equivalent to calling C<$h-E<gt>aug_set> C<expr>, C<value>.
129 C<name> will be the nodeset containing that single node.
131 On success this returns a pair containing the
132 number of nodes in the nodeset, and a boolean flag
133 if a node was created.
135 =item $nrnodes = $h->aug_defvar ($name, $expr);
137 Defines an Augeas variable C<name> whose value is the result
138 of evaluating C<expr>. If C<expr> is NULL, then C<name> is
141 On success this returns the number of nodes in C<expr>, or
142 C<0> if C<expr> evaluates to something which is not a nodeset.
144 =item $val = $h->aug_get ($path);
146 Look up the value associated with C<path>. If C<path>
147 matches exactly one node, the C<value> is returned.
149 =item $h->aug_init ($root, $flags);
151 Create a new Augeas handle for editing configuration files.
152 If there was any previous Augeas handle associated with this
153 guestfs session, then it is closed.
155 You must call this before using any other C<$h-E<gt>aug_*>
158 C<root> is the filesystem root. C<root> must not be NULL,
161 The flags are the same as the flags defined in
162 E<lt>augeas.hE<gt>, the logical I<or> of the following
167 =item C<AUG_SAVE_BACKUP> = 1
169 Keep the original file with a C<.augsave> extension.
171 =item C<AUG_SAVE_NEWFILE> = 2
173 Save changes into a file with extension C<.augnew>, and
174 do not overwrite original. Overrides C<AUG_SAVE_BACKUP>.
176 =item C<AUG_TYPE_CHECK> = 4
178 Typecheck lenses (can be expensive).
180 =item C<AUG_NO_STDINC> = 8
182 Do not use standard load path for modules.
184 =item C<AUG_SAVE_NOOP> = 16
186 Make save a no-op, just record what would have been changed.
188 =item C<AUG_NO_LOAD> = 32
190 Do not load the tree in C<$h-E<gt>aug_init>.
194 To close the handle, you can call C<$h-E<gt>aug_close>.
196 To find out more about Augeas, see L<http://augeas.net/>.
198 =item $h->aug_insert ($path, $label, $before);
200 Create a new sibling C<label> for C<path>, inserting it into
201 the tree before or after C<path> (depending on the boolean
204 C<path> must match exactly one existing node in the tree, and
205 C<label> must be a label, ie. not contain C</>, C<*> or end
206 with a bracketed index C<[N]>.
208 =item $h->aug_load ();
210 Load files into the tree.
212 See C<aug_load> in the Augeas documentation for the full gory
215 =item @matches = $h->aug_ls ($path);
217 This is just a shortcut for listing C<$h-E<gt>aug_match>
218 C<path/*> and sorting the resulting nodes into alphabetical order.
220 =item @matches = $h->aug_match ($path);
222 Returns a list of paths which match the path expression C<path>.
223 The returned paths are sufficiently qualified so that they match
224 exactly one node in the current tree.
226 =item $h->aug_mv ($src, $dest);
228 Move the node C<src> to C<dest>. C<src> must match exactly
229 one node. C<dest> is overwritten if it exists.
231 =item $nrnodes = $h->aug_rm ($path);
233 Remove C<path> and all of its children.
235 On success this returns the number of entries which were removed.
237 =item $h->aug_save ();
239 This writes all pending changes to disk.
241 The flags which were passed to C<$h-E<gt>aug_init> affect exactly
244 =item $h->aug_set ($path, $val);
246 Set the value associated with C<path> to C<value>.
248 =item $h->blockdev_flushbufs ($device);
250 This tells the kernel to flush internal buffers associated
253 This uses the L<blockdev(8)> command.
255 =item $blocksize = $h->blockdev_getbsz ($device);
257 This returns the block size of a device.
259 (Note this is different from both I<size in blocks> and
260 I<filesystem block size>).
262 This uses the L<blockdev(8)> command.
264 =item $ro = $h->blockdev_getro ($device);
266 Returns a boolean indicating if the block device is read-only
267 (true if read-only, false if not).
269 This uses the L<blockdev(8)> command.
271 =item $sizeinbytes = $h->blockdev_getsize64 ($device);
273 This returns the size of the device in bytes.
275 See also C<$h-E<gt>blockdev_getsz>.
277 This uses the L<blockdev(8)> command.
279 =item $sectorsize = $h->blockdev_getss ($device);
281 This returns the size of sectors on a block device.
282 Usually 512, but can be larger for modern devices.
284 (Note, this is not the size in sectors, use C<$h-E<gt>blockdev_getsz>
287 This uses the L<blockdev(8)> command.
289 =item $sizeinsectors = $h->blockdev_getsz ($device);
291 This returns the size of the device in units of 512-byte sectors
292 (even if the sectorsize isn't 512 bytes ... weird).
294 See also C<$h-E<gt>blockdev_getss> for the real sector size of
295 the device, and C<$h-E<gt>blockdev_getsize64> for the more
296 useful I<size in bytes>.
298 This uses the L<blockdev(8)> command.
300 =item $h->blockdev_rereadpt ($device);
302 Reread the partition table on C<device>.
304 This uses the L<blockdev(8)> command.
306 =item $h->blockdev_setbsz ($device, $blocksize);
308 This sets the block size of a device.
310 (Note this is different from both I<size in blocks> and
311 I<filesystem block size>).
313 This uses the L<blockdev(8)> command.
315 =item $h->blockdev_setro ($device);
317 Sets the block device named C<device> to read-only.
319 This uses the L<blockdev(8)> command.
321 =item $h->blockdev_setrw ($device);
323 Sets the block device named C<device> to read-write.
325 This uses the L<blockdev(8)> command.
327 =item $content = $h->cat ($path);
329 Return the contents of the file named C<path>.
331 Note that this function cannot correctly handle binary files
332 (specifically, files containing C<\0> character which is treated
333 as end of string). For those you need to use the C<$h-E<gt>download>
334 function which has a more complex interface.
336 Because of the message protocol, there is a transfer limit
337 of somewhere between 2MB and 4MB. To transfer large files you should use
340 =item $checksum = $h->checksum ($csumtype, $path);
342 This call computes the MD5, SHAx or CRC checksum of the
345 The type of checksum to compute is given by the C<csumtype>
346 parameter which must have one of the following values:
352 Compute the cyclic redundancy check (CRC) specified by POSIX
353 for the C<cksum> command.
357 Compute the MD5 hash (using the C<md5sum> program).
361 Compute the SHA1 hash (using the C<sha1sum> program).
365 Compute the SHA224 hash (using the C<sha224sum> program).
369 Compute the SHA256 hash (using the C<sha256sum> program).
373 Compute the SHA384 hash (using the C<sha384sum> program).
377 Compute the SHA512 hash (using the C<sha512sum> program).
381 The checksum is returned as a printable string.
383 =item $h->chmod ($mode, $path);
385 Change the mode (permissions) of C<path> to C<mode>. Only
386 numeric modes are supported.
388 =item $h->chown ($owner, $group, $path);
390 Change the file owner to C<owner> and group to C<group>.
392 Only numeric uid and gid are supported. If you want to use
393 names, you will need to locate and parse the password file
394 yourself (Augeas support makes this relatively easy).
396 =item $output = $h->command (\@arguments);
398 This call runs a command from the guest filesystem. The
399 filesystem must be mounted, and must contain a compatible
400 operating system (ie. something Linux, with the same
401 or compatible processor architecture).
403 The single parameter is an argv-style list of arguments.
404 The first element is the name of the program to run.
405 Subsequent elements are parameters. The list must be
406 non-empty (ie. must contain a program name).
408 The return value is anything printed to I<stdout> by
411 If the command returns a non-zero exit status, then
412 this function returns an error message. The error message
413 string is the content of I<stderr> from the command.
415 The C<$PATH> environment variable will contain at least
416 C</usr/bin> and C</bin>. If you require a program from
417 another location, you should provide the full path in the
420 Shared libraries and data files required by the program
421 must be available on filesystems which are mounted in the
422 correct places. It is the caller's responsibility to ensure
423 all filesystems that are needed are mounted at the right
426 Because of the message protocol, there is a transfer limit
427 of somewhere between 2MB and 4MB. To transfer large files you should use
430 =item @lines = $h->command_lines (\@arguments);
432 This is the same as C<$h-E<gt>command>, but splits the
433 result into a list of lines.
435 Because of the message protocol, there is a transfer limit
436 of somewhere between 2MB and 4MB. To transfer large files you should use
439 =item $h->config ($qemuparam, $qemuvalue);
441 This can be used to add arbitrary qemu command line parameters
442 of the form C<-param value>. Actually it's not quite arbitrary - we
443 prevent you from setting some parameters which would interfere with
444 parameters that we use.
446 The first character of C<param> string must be a C<-> (dash).
448 C<value> can be NULL.
450 =item $h->cp ($src, $dest);
452 This copies a file from C<src> to C<dest> where C<dest> is
453 either a destination filename or destination directory.
455 =item $h->cp_a ($src, $dest);
457 This copies a file or directory from C<src> to C<dest>
458 recursively using the C<cp -a> command.
460 =item $result = $h->debug ($subcmd, \@extraargs);
462 The C<$h-E<gt>debug> command exposes some internals of
463 C<guestfsd> (the guestfs daemon) that runs inside the
466 There is no comprehensive help for this command. You have
467 to look at the file C<daemon/debug.c> in the libguestfs source
468 to find out what you can do.
470 =item $kmsgs = $h->dmesg ();
472 This returns the kernel messages (C<dmesg> output) from
473 the guest kernel. This is sometimes useful for extended
474 debugging of problems.
476 Another way to get the same information is to enable
477 verbose messages with C<$h-E<gt>set_verbose> or by setting
478 the environment variable C<LIBGUESTFS_DEBUG=1> before
481 =item $h->download ($remotefilename, $filename);
483 Download file C<remotefilename> and save it as C<filename>
484 on the local machine.
486 C<filename> can also be a named pipe.
488 See also C<$h-E<gt>upload>, C<$h-E<gt>cat>.
490 =item $h->drop_caches ($whattodrop);
492 This instructs the guest kernel to drop its page cache,
493 and/or dentries and inode caches. The parameter C<whattodrop>
494 tells the kernel what precisely to drop, see
495 L<http://linux-mm.org/Drop_Caches>
497 Setting C<whattodrop> to 3 should drop everything.
499 This automatically calls L<sync(2)> before the operation,
500 so that the maximum guest memory is freed.
502 =item $h->e2fsck_f ($device);
504 This runs C<e2fsck -p -f device>, ie. runs the ext2/ext3
505 filesystem checker on C<device>, noninteractively (C<-p>),
506 even if the filesystem appears to be clean (C<-f>).
508 This command is only needed because of C<$h-E<gt>resize2fs>
509 (q.v.). Normally you should use C<$h-E<gt>fsck>.
511 =item $h->end_busy ();
513 This sets the state to C<READY>, or if in C<CONFIG> then it leaves the
514 state as is. This is only used when implementing
515 actions using the low-level API.
517 For more information on states, see L<guestfs(3)>.
519 =item $equality = $h->equal ($file1, $file2);
521 This compares the two files C<file1> and C<file2> and returns
522 true if their content is exactly equal, or false otherwise.
524 The external L<cmp(1)> program is used for the comparison.
526 =item $existsflag = $h->exists ($path);
528 This returns C<true> if and only if there is a file, directory
529 (or anything) with the given C<path> name.
531 See also C<$h-E<gt>is_file>, C<$h-E<gt>is_dir>, C<$h-E<gt>stat>.
533 =item $description = $h->file ($path);
535 This call uses the standard L<file(1)> command to determine
536 the type or contents of the file. This also works on devices,
537 for example to find out whether a partition contains a filesystem.
539 The exact command which runs is C<file -bsL path>. Note in
540 particular that the filename is not prepended to the output
543 =item @names = $h->find ($directory);
545 This command lists out all files and directories, recursively,
546 starting at C<directory>. It is essentially equivalent to
547 running the shell command C<find directory -print> but some
548 post-processing happens on the output, described below.
550 This returns a list of strings I<without any prefix>. Thus
551 if the directory structure was:
557 then the returned list from C<$h-E<gt>find> C</tmp> would be
565 If C<directory> is not a directory, then this command returns
568 The returned list is sorted.
570 =item $status = $h->fsck ($fstype, $device);
572 This runs the filesystem checker (fsck) on C<device> which
573 should have filesystem type C<fstype>.
575 The returned integer is the status. See L<fsck(8)> for the
576 list of status codes from C<fsck>.
584 Multiple status codes can be summed together.
588 A non-zero return code can mean "success", for example if
589 errors have been corrected on the filesystem.
593 Checking or repairing NTFS volumes is not supported
598 This command is entirely equivalent to running C<fsck -a -t fstype device>.
600 =item $append = $h->get_append ();
602 Return the additional kernel options which are added to the
603 guest kernel command line.
605 If C<NULL> then no options are added.
607 =item $autosync = $h->get_autosync ();
609 Get the autosync flag.
611 =item $label = $h->get_e2label ($device);
613 This returns the ext2/3/4 filesystem label of the filesystem on
616 =item $uuid = $h->get_e2uuid ($device);
618 This returns the ext2/3/4 filesystem UUID of the filesystem on
621 =item $path = $h->get_path ();
623 Return the current search path.
625 This is always non-NULL. If it wasn't set already, then this will
626 return the default path.
628 =item $qemu = $h->get_qemu ();
630 Return the current qemu binary.
632 This is always non-NULL. If it wasn't set already, then this will
633 return the default qemu binary name.
635 =item $state = $h->get_state ();
637 This returns the current state as an opaque integer. This is
638 only useful for printing debug and internal error messages.
640 For more information on states, see L<guestfs(3)>.
642 =item $verbose = $h->get_verbose ();
644 This returns the verbose messages flag.
646 =item $h->grub_install ($root, $device);
648 This command installs GRUB (the Grand Unified Bootloader) on
649 C<device>, with the root directory being C<root>.
651 =item $dump = $h->hexdump ($path);
653 This runs C<hexdump -C> on the given C<path>. The result is
654 the human-readable, canonical hex dump of the file.
656 Because of the message protocol, there is a transfer limit
657 of somewhere between 2MB and 4MB. To transfer large files you should use
660 =item $busy = $h->is_busy ();
662 This returns true iff this handle is busy processing a command
663 (in the C<BUSY> state).
665 For more information on states, see L<guestfs(3)>.
667 =item $config = $h->is_config ();
669 This returns true iff this handle is being configured
670 (in the C<CONFIG> state).
672 For more information on states, see L<guestfs(3)>.
674 =item $dirflag = $h->is_dir ($path);
676 This returns C<true> if and only if there is a directory
677 with the given C<path> name. Note that it returns false for
678 other objects like files.
680 See also C<$h-E<gt>stat>.
682 =item $fileflag = $h->is_file ($path);
684 This returns C<true> if and only if there is a file
685 with the given C<path> name. Note that it returns false for
686 other objects like directories.
688 See also C<$h-E<gt>stat>.
690 =item $launching = $h->is_launching ();
692 This returns true iff this handle is launching the subprocess
693 (in the C<LAUNCHING> state).
695 For more information on states, see L<guestfs(3)>.
697 =item $ready = $h->is_ready ();
699 This returns true iff this handle is ready to accept commands
700 (in the C<READY> state).
702 For more information on states, see L<guestfs(3)>.
704 =item $h->kill_subprocess ();
706 This kills the qemu subprocess. You should never need to call this.
710 Internally libguestfs is implemented by running a virtual machine
713 You should call this after configuring the handle
714 (eg. adding drives) but before performing any actions.
716 =item @devices = $h->list_devices ();
718 List all the block devices.
720 The full block device names are returned, eg. C</dev/sda>
722 =item @partitions = $h->list_partitions ();
724 List all the partitions detected on all block devices.
726 The full partition device names are returned, eg. C</dev/sda1>
728 This does not return logical volumes. For that you will need to
731 =item $listing = $h->ll ($directory);
733 List the files in C<directory> (relative to the root directory,
734 there is no cwd) in the format of 'ls -la'.
736 This command is mostly useful for interactive sessions. It
737 is I<not> intended that you try to parse the output string.
739 =item @listing = $h->ls ($directory);
741 List the files in C<directory> (relative to the root directory,
742 there is no cwd). The '.' and '..' entries are not returned, but
743 hidden files are shown.
745 This command is mostly useful for interactive sessions. Programs
746 should probably use C<$h-E<gt>readdir> instead.
748 =item %statbuf = $h->lstat ($path);
750 Returns file information for the given C<path>.
752 This is the same as C<$h-E<gt>stat> except that if C<path>
753 is a symbolic link, then the link is stat-ed, not the file it
756 This is the same as the C<lstat(2)> system call.
758 =item $h->lvcreate ($logvol, $volgroup, $mbytes);
760 This creates an LVM volume group called C<logvol>
761 on the volume group C<volgroup>, with C<size> megabytes.
763 =item $h->lvm_remove_all ();
765 This command removes all LVM logical volumes, volume groups
766 and physical volumes.
768 B<This command is dangerous. Without careful use you
769 can easily destroy all your data>.
771 =item $h->lvremove ($device);
773 Remove an LVM logical volume C<device>, where C<device> is
774 the path to the LV, such as C</dev/VG/LV>.
776 You can also remove all LVs in a volume group by specifying
777 the VG name, C</dev/VG>.
779 =item $h->lvresize ($device, $mbytes);
781 This resizes (expands or shrinks) an existing LVM logical
782 volume to C<mbytes>. When reducing, data in the reduced part
785 =item @logvols = $h->lvs ();
787 List all the logical volumes detected. This is the equivalent
788 of the L<lvs(8)> command.
790 This returns a list of the logical volume device names
791 (eg. C</dev/VolGroup00/LogVol00>).
793 See also C<$h-E<gt>lvs_full>.
795 =item @logvols = $h->lvs_full ();
797 List all the logical volumes detected. This is the equivalent
798 of the L<lvs(8)> command. The "full" version includes all fields.
800 =item $h->mkdir ($path);
802 Create a directory named C<path>.
804 =item $h->mkdir_p ($path);
806 Create a directory named C<path>, creating any parent directories
807 as necessary. This is like the C<mkdir -p> shell command.
809 =item $h->mkfs ($fstype, $device);
811 This creates a filesystem on C<device> (usually a partition
812 or LVM logical volume). The filesystem type is C<fstype>, for
815 =item $h->mount ($device, $mountpoint);
817 Mount a guest disk at a position in the filesystem. Block devices
818 are named C</dev/sda>, C</dev/sdb> and so on, as they were added to
819 the guest. If those block devices contain partitions, they will have
820 the usual names (eg. C</dev/sda1>). Also LVM C</dev/VG/LV>-style
823 The rules are the same as for L<mount(2)>: A filesystem must
824 first be mounted on C</> before others can be mounted. Other
825 filesystems can only be mounted on directories which already
828 The mounted filesystem is writable, if we have sufficient permissions
829 on the underlying device.
831 The filesystem options C<sync> and C<noatime> are set with this
832 call, in order to improve reliability.
834 =item $h->mount_options ($options, $device, $mountpoint);
836 This is the same as the C<$h-E<gt>mount> command, but it
837 allows you to set the mount options as for the
838 L<mount(8)> I<-o> flag.
840 =item $h->mount_ro ($device, $mountpoint);
842 This is the same as the C<$h-E<gt>mount> command, but it
843 mounts the filesystem with the read-only (I<-o ro>) flag.
845 =item $h->mount_vfs ($options, $vfstype, $device, $mountpoint);
847 This is the same as the C<$h-E<gt>mount> command, but it
848 allows you to set both the mount options and the vfstype
849 as for the L<mount(8)> I<-o> and I<-t> flags.
851 =item @devices = $h->mounts ();
853 This returns the list of currently mounted filesystems. It returns
854 the list of devices (eg. C</dev/sda1>, C</dev/VG/LV>).
856 Some internal mounts are not shown.
858 =item $h->mv ($src, $dest);
860 This moves a file from C<src> to C<dest> where C<dest> is
861 either a destination filename or destination directory.
863 =item $h->ping_daemon ();
865 This is a test probe into the guestfs daemon running inside
866 the qemu subprocess. Calling this function checks that the
867 daemon responds to the ping message, without affecting the daemon
868 or attached block device(s) in any other way.
870 =item $h->pvcreate ($device);
872 This creates an LVM physical volume on the named C<device>,
873 where C<device> should usually be a partition name such
876 =item $h->pvremove ($device);
878 This wipes a physical volume C<device> so that LVM will no longer
881 The implementation uses the C<pvremove> command which refuses to
882 wipe physical volumes that contain any volume groups, so you have
883 to remove those first.
885 =item $h->pvresize ($device);
887 This resizes (expands or shrinks) an existing LVM physical
888 volume to match the new size of the underlying device.
890 =item @physvols = $h->pvs ();
892 List all the physical volumes detected. This is the equivalent
893 of the L<pvs(8)> command.
895 This returns a list of just the device names that contain
896 PVs (eg. C</dev/sda2>).
898 See also C<$h-E<gt>pvs_full>.
900 =item @physvols = $h->pvs_full ();
902 List all the physical volumes detected. This is the equivalent
903 of the L<pvs(8)> command. The "full" version includes all fields.
905 =item @lines = $h->read_lines ($path);
907 Return the contents of the file named C<path>.
909 The file contents are returned as a list of lines. Trailing
910 C<LF> and C<CRLF> character sequences are I<not> returned.
912 Note that this function cannot correctly handle binary files
913 (specifically, files containing C<\0> character which is treated
914 as end of line). For those you need to use the C<$h-E<gt>read_file>
915 function which has a more complex interface.
917 =item $h->resize2fs ($device);
919 This resizes an ext2 or ext3 filesystem to match the size of
920 the underlying device.
922 I<Note:> It is sometimes required that you run C<$h-E<gt>e2fsck_f>
923 on the C<device> before calling this command. For unknown reasons
924 C<resize2fs> sometimes gives an error about this and sometimes not.
925 In any case, it is always safe to call C<$h-E<gt>e2fsck_f> before
926 calling this function.
928 =item $h->rm ($path);
930 Remove the single file C<path>.
932 =item $h->rm_rf ($path);
934 Remove the file or directory C<path>, recursively removing the
935 contents if its a directory. This is like the C<rm -rf> shell
938 =item $h->rmdir ($path);
940 Remove the single directory C<path>.
942 =item $h->set_append ($append);
944 This function is used to add additional options to the
945 guest kernel command line.
947 The default is C<NULL> unless overridden by setting
948 C<LIBGUESTFS_APPEND> environment variable.
950 Setting C<append> to C<NULL> means I<no> additional options
951 are passed (libguestfs always adds a few of its own).
953 =item $h->set_autosync ($autosync);
955 If C<autosync> is true, this enables autosync. Libguestfs will make a
956 best effort attempt to run C<$h-E<gt>umount_all> followed by
957 C<$h-E<gt>sync> when the handle is closed
958 (also if the program exits without closing handles).
960 This is disabled by default (except in guestfish where it is
963 =item $h->set_busy ();
965 This sets the state to C<BUSY>. This is only used when implementing
966 actions using the low-level API.
968 For more information on states, see L<guestfs(3)>.
970 =item $h->set_e2label ($device, $label);
972 This sets the ext2/3/4 filesystem label of the filesystem on
973 C<device> to C<label>. Filesystem labels are limited to
976 You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2label>
977 to return the existing label on a filesystem.
979 =item $h->set_e2uuid ($device, $uuid);
981 This sets the ext2/3/4 filesystem UUID of the filesystem on
982 C<device> to C<uuid>. The format of the UUID and alternatives
983 such as C<clear>, C<random> and C<time> are described in the
984 L<tune2fs(8)> manpage.
986 You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2uuid>
987 to return the existing UUID of a filesystem.
989 =item $h->set_path ($path);
991 Set the path that libguestfs searches for kernel and initrd.img.
993 The default is C<$libdir/guestfs> unless overridden by setting
994 C<LIBGUESTFS_PATH> environment variable.
996 Setting C<path> to C<NULL> restores the default path.
998 =item $h->set_qemu ($qemu);
1000 Set the qemu binary that we will use.
1002 The default is chosen when the library was compiled by the
1005 You can also override this by setting the C<LIBGUESTFS_QEMU>
1006 environment variable.
1008 Setting C<qemu> to C<NULL> restores the default qemu binary.
1010 =item $h->set_ready ();
1012 This sets the state to C<READY>. This is only used when implementing
1013 actions using the low-level API.
1015 For more information on states, see L<guestfs(3)>.
1017 =item $h->set_verbose ($verbose);
1019 If C<verbose> is true, this turns on verbose messages (to C<stderr>).
1021 Verbose messages are disabled unless the environment variable
1022 C<LIBGUESTFS_DEBUG> is defined and set to C<1>.
1024 =item $h->sfdisk ($device, $cyls, $heads, $sectors, \@lines);
1026 This is a direct interface to the L<sfdisk(8)> program for creating
1027 partitions on block devices.
1029 C<device> should be a block device, for example C</dev/sda>.
1031 C<cyls>, C<heads> and C<sectors> are the number of cylinders, heads
1032 and sectors on the device, which are passed directly to sfdisk as
1033 the I<-C>, I<-H> and I<-S> parameters. If you pass C<0> for any
1034 of these, then the corresponding parameter is omitted. Usually for
1035 'large' disks, you can just pass C<0> for these, but for small
1036 (floppy-sized) disks, sfdisk (or rather, the kernel) cannot work
1037 out the right geometry and you will need to tell it.
1039 C<lines> is a list of lines that we feed to C<sfdisk>. For more
1040 information refer to the L<sfdisk(8)> manpage.
1042 To create a single partition occupying the whole disk, you would
1043 pass C<lines> as a single element list, when the single element being
1044 the string C<,> (comma).
1046 See also: C<$h-E<gt>sfdisk_l>, C<$h-E<gt>sfdisk_N>
1048 B<This command is dangerous. Without careful use you
1049 can easily destroy all your data>.
1051 =item $h->sfdisk_N ($device, $n, $cyls, $heads, $sectors, $line);
1053 This runs L<sfdisk(8)> option to modify just the single
1054 partition C<n> (note: C<n> counts from 1).
1056 For other parameters, see C<$h-E<gt>sfdisk>. You should usually
1057 pass C<0> for the cyls/heads/sectors parameters.
1059 B<This command is dangerous. Without careful use you
1060 can easily destroy all your data>.
1062 =item $partitions = $h->sfdisk_disk_geometry ($device);
1064 This displays the disk geometry of C<device> read from the
1065 partition table. Especially in the case where the underlying
1066 block device has been resized, this can be different from the
1067 kernel's idea of the geometry (see C<$h-E<gt>sfdisk_kernel_geometry>).
1069 The result is in human-readable format, and not designed to
1072 =item $partitions = $h->sfdisk_kernel_geometry ($device);
1074 This displays the kernel's idea of the geometry of C<device>.
1076 The result is in human-readable format, and not designed to
1079 =item $partitions = $h->sfdisk_l ($device);
1081 This displays the partition table on C<device>, in the
1082 human-readable output of the L<sfdisk(8)> command. It is
1083 not intended to be parsed.
1085 =item %statbuf = $h->stat ($path);
1087 Returns file information for the given C<path>.
1089 This is the same as the C<stat(2)> system call.
1091 =item %statbuf = $h->statvfs ($path);
1093 Returns file system statistics for any mounted file system.
1094 C<path> should be a file or directory in the mounted file system
1095 (typically it is the mount point itself, but it doesn't need to be).
1097 This is the same as the C<statvfs(2)> system call.
1099 =item @stringsout = $h->strings ($path);
1101 This runs the L<strings(1)> command on a file and returns
1102 the list of printable strings found.
1104 Because of the message protocol, there is a transfer limit
1105 of somewhere between 2MB and 4MB. To transfer large files you should use
1108 =item @stringsout = $h->strings_e ($encoding, $path);
1110 This is like the C<$h-E<gt>strings> command, but allows you to
1111 specify the encoding.
1113 See the L<strings(1)> manpage for the full list of encodings.
1115 Commonly useful encodings are C<l> (lower case L) which will
1116 show strings inside Windows/x86 files.
1118 The returned strings are transcoded to UTF-8.
1120 Because of the message protocol, there is a transfer limit
1121 of somewhere between 2MB and 4MB. To transfer large files you should use
1126 This syncs the disk, so that any writes are flushed through to the
1127 underlying disk image.
1129 You should always call this if you have modified a disk image, before
1132 =item $h->tar_in ($tarfile, $directory);
1134 This command uploads and unpacks local file C<tarfile> (an
1135 I<uncompressed> tar file) into C<directory>.
1137 To upload a compressed tarball, use C<$h-E<gt>tgz_in>.
1139 =item $h->tar_out ($directory, $tarfile);
1141 This command packs the contents of C<directory> and downloads
1142 it to local file C<tarfile>.
1144 To download a compressed tarball, use C<$h-E<gt>tgz_out>.
1146 =item $h->tgz_in ($tarball, $directory);
1148 This command uploads and unpacks local file C<tarball> (a
1149 I<gzip compressed> tar file) into C<directory>.
1151 To upload an uncompressed tarball, use C<$h-E<gt>tar_in>.
1153 =item $h->tgz_out ($directory, $tarball);
1155 This command packs the contents of C<directory> and downloads
1156 it to local file C<tarball>.
1158 To download an uncompressed tarball, use C<$h-E<gt>tar_out>.
1160 =item $h->touch ($path);
1162 Touch acts like the L<touch(1)> command. It can be used to
1163 update the timestamps on a file, or, if the file does not exist,
1164 to create a new zero-length file.
1166 =item %superblock = $h->tune2fs_l ($device);
1168 This returns the contents of the ext2, ext3 or ext4 filesystem
1169 superblock on C<device>.
1171 It is the same as running C<tune2fs -l device>. See L<tune2fs(8)>
1172 manpage for more details. The list of fields returned isn't
1173 clearly defined, and depends on both the version of C<tune2fs>
1174 that libguestfs was built against, and the filesystem itself.
1176 =item $h->umount ($pathordevice);
1178 This unmounts the given filesystem. The filesystem may be
1179 specified either by its mountpoint (path) or the device which
1180 contains the filesystem.
1182 =item $h->umount_all ();
1184 This unmounts all mounted filesystems.
1186 Some internal mounts are not unmounted by this call.
1188 =item $h->upload ($filename, $remotefilename);
1190 Upload local file C<filename> to C<remotefilename> on the
1193 C<filename> can also be a named pipe.
1195 See also C<$h-E<gt>download>.
1197 =item $h->vg_activate ($activate, \@volgroups);
1199 This command activates or (if C<activate> is false) deactivates
1200 all logical volumes in the listed volume groups C<volgroups>.
1201 If activated, then they are made known to the
1202 kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
1203 then those devices disappear.
1205 This command is the same as running C<vgchange -a y|n volgroups...>
1207 Note that if C<volgroups> is an empty list then B<all> volume groups
1208 are activated or deactivated.
1210 =item $h->vg_activate_all ($activate);
1212 This command activates or (if C<activate> is false) deactivates
1213 all logical volumes in all volume groups.
1214 If activated, then they are made known to the
1215 kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
1216 then those devices disappear.
1218 This command is the same as running C<vgchange -a y|n>
1220 =item $h->vgcreate ($volgroup, \@physvols);
1222 This creates an LVM volume group called C<volgroup>
1223 from the non-empty list of physical volumes C<physvols>.
1225 =item $h->vgremove ($vgname);
1227 Remove an LVM volume group C<vgname>, (for example C<VG>).
1229 This also forcibly removes all logical volumes in the volume
1232 =item @volgroups = $h->vgs ();
1234 List all the volumes groups detected. This is the equivalent
1235 of the L<vgs(8)> command.
1237 This returns a list of just the volume group names that were
1238 detected (eg. C<VolGroup00>).
1240 See also C<$h-E<gt>vgs_full>.
1242 =item @volgroups = $h->vgs_full ();
1244 List all the volumes groups detected. This is the equivalent
1245 of the L<vgs(8)> command. The "full" version includes all fields.
1247 =item $h->wait_ready ();
1249 Internally libguestfs is implemented by running a virtual machine
1252 You should call this after C<$h-E<gt>launch> to wait for the launch
1255 =item $h->write_file ($path, $content, $size);
1257 This call creates a file called C<path>. The contents of the
1258 file is the string C<content> (which can contain any 8 bit data),
1259 with length C<size>.
1261 As a special case, if C<size> is C<0>
1262 then the length is calculated using C<strlen> (so in this case
1263 the content cannot contain embedded ASCII NULs).
1265 I<NB.> Owing to a bug, writing content containing ASCII NUL
1266 characters does I<not> work, even if the length is specified.
1267 We hope to resolve this bug in a future version. In the meantime
1268 use C<$h-E<gt>upload>.
1270 Because of the message protocol, there is a transfer limit
1271 of somewhere between 2MB and 4MB. To transfer large files you should use
1274 =item $h->zero ($device);
1276 This command writes zeroes over the first few blocks of C<device>.
1278 How many blocks are zeroed isn't specified (but it's I<not> enough
1279 to securely wipe the device). It should be sufficient to remove
1280 any partition tables, filesystem superblocks and so on.
1282 =item $h->zerofree ($device);
1284 This runs the I<zerofree> program on C<device>. This program
1285 claims to zero unused inodes and disk blocks on an ext2/3
1286 filesystem, thus making it possible to compress the filesystem
1289 You should B<not> run this program if the filesystem is
1292 It is possible that using this program can damage the filesystem
1293 or data on the filesystem.
1303 Copyright (C) 2009 Red Hat Inc.
1307 Please see the file COPYING.LIB for the full license.
1311 L<guestfs(3)>, L<guestfish(1)>.