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2 # WARNING: THIS FILE IS GENERATED BY 'src/generator.ml'.
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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 Note that this call checks for the existence of C<filename>. This
101 stops you from specifying other types of drive which are supported
102 by qemu such as C<nbd:> and C<http:> URLs. To specify those, use
103 the general C<$h-E<gt>config> call instead.
105 =item $h->add_drive ($filename);
107 This function adds a virtual machine disk image C<filename> to the
108 guest. The first time you call this function, the disk appears as IDE
109 disk 0 (C</dev/sda>) in the guest, the second time as C</dev/sdb>, and
112 You don't necessarily need to be root when using libguestfs. However
113 you obviously do need sufficient permissions to access the filename
114 for whatever operations you want to perform (ie. read access if you
115 just want to read the image or write access if you want to modify the
118 This is equivalent to the qemu parameter C<-drive file=filename,cache=off>.
120 Note that this call checks for the existence of C<filename>. This
121 stops you from specifying other types of drive which are supported
122 by qemu such as C<nbd:> and C<http:> URLs. To specify those, use
123 the general C<$h-E<gt>config> call instead.
125 =item $h->add_drive_ro ($filename);
127 This adds a drive in snapshot mode, making it effectively
130 Note that writes to the device are allowed, and will be seen for
131 the duration of the guestfs handle, but they are written
132 to a temporary file which is discarded as soon as the guestfs
133 handle is closed. We don't currently have any method to enable
134 changes to be committed, although qemu can support this.
136 This is equivalent to the qemu parameter
137 C<-drive file=filename,snapshot=on>.
139 Note that this call checks for the existence of C<filename>. This
140 stops you from specifying other types of drive which are supported
141 by qemu such as C<nbd:> and C<http:> URLs. To specify those, use
142 the general C<$h-E<gt>config> call instead.
144 =item $h->aug_close ();
146 Close the current Augeas handle and free up any resources
147 used by it. After calling this, you have to call
148 C<$h-E<gt>aug_init> again before you can use any other
151 =item ($nrnodes, $created) = $h->aug_defnode ($name, $expr, $val);
153 Defines a variable C<name> whose value is the result of
156 If C<expr> evaluates to an empty nodeset, a node is created,
157 equivalent to calling C<$h-E<gt>aug_set> C<expr>, C<value>.
158 C<name> will be the nodeset containing that single node.
160 On success this returns a pair containing the
161 number of nodes in the nodeset, and a boolean flag
162 if a node was created.
164 =item $nrnodes = $h->aug_defvar ($name, $expr);
166 Defines an Augeas variable C<name> whose value is the result
167 of evaluating C<expr>. If C<expr> is NULL, then C<name> is
170 On success this returns the number of nodes in C<expr>, or
171 C<0> if C<expr> evaluates to something which is not a nodeset.
173 =item $val = $h->aug_get ($path);
175 Look up the value associated with C<path>. If C<path>
176 matches exactly one node, the C<value> is returned.
178 =item $h->aug_init ($root, $flags);
180 Create a new Augeas handle for editing configuration files.
181 If there was any previous Augeas handle associated with this
182 guestfs session, then it is closed.
184 You must call this before using any other C<$h-E<gt>aug_*>
187 C<root> is the filesystem root. C<root> must not be NULL,
190 The flags are the same as the flags defined in
191 E<lt>augeas.hE<gt>, the logical I<or> of the following
196 =item C<AUG_SAVE_BACKUP> = 1
198 Keep the original file with a C<.augsave> extension.
200 =item C<AUG_SAVE_NEWFILE> = 2
202 Save changes into a file with extension C<.augnew>, and
203 do not overwrite original. Overrides C<AUG_SAVE_BACKUP>.
205 =item C<AUG_TYPE_CHECK> = 4
207 Typecheck lenses (can be expensive).
209 =item C<AUG_NO_STDINC> = 8
211 Do not use standard load path for modules.
213 =item C<AUG_SAVE_NOOP> = 16
215 Make save a no-op, just record what would have been changed.
217 =item C<AUG_NO_LOAD> = 32
219 Do not load the tree in C<$h-E<gt>aug_init>.
223 To close the handle, you can call C<$h-E<gt>aug_close>.
225 To find out more about Augeas, see L<http://augeas.net/>.
227 =item $h->aug_insert ($path, $label, $before);
229 Create a new sibling C<label> for C<path>, inserting it into
230 the tree before or after C<path> (depending on the boolean
233 C<path> must match exactly one existing node in the tree, and
234 C<label> must be a label, ie. not contain C</>, C<*> or end
235 with a bracketed index C<[N]>.
237 =item $h->aug_load ();
239 Load files into the tree.
241 See C<aug_load> in the Augeas documentation for the full gory
244 =item @matches = $h->aug_ls ($path);
246 This is just a shortcut for listing C<$h-E<gt>aug_match>
247 C<path/*> and sorting the resulting nodes into alphabetical order.
249 =item @matches = $h->aug_match ($path);
251 Returns a list of paths which match the path expression C<path>.
252 The returned paths are sufficiently qualified so that they match
253 exactly one node in the current tree.
255 =item $h->aug_mv ($src, $dest);
257 Move the node C<src> to C<dest>. C<src> must match exactly
258 one node. C<dest> is overwritten if it exists.
260 =item $nrnodes = $h->aug_rm ($path);
262 Remove C<path> and all of its children.
264 On success this returns the number of entries which were removed.
266 =item $h->aug_save ();
268 This writes all pending changes to disk.
270 The flags which were passed to C<$h-E<gt>aug_init> affect exactly
273 =item $h->aug_set ($path, $val);
275 Set the value associated with C<path> to C<value>.
277 =item $h->blockdev_flushbufs ($device);
279 This tells the kernel to flush internal buffers associated
282 This uses the L<blockdev(8)> command.
284 =item $blocksize = $h->blockdev_getbsz ($device);
286 This returns the block size of a device.
288 (Note this is different from both I<size in blocks> and
289 I<filesystem block size>).
291 This uses the L<blockdev(8)> command.
293 =item $ro = $h->blockdev_getro ($device);
295 Returns a boolean indicating if the block device is read-only
296 (true if read-only, false if not).
298 This uses the L<blockdev(8)> command.
300 =item $sizeinbytes = $h->blockdev_getsize64 ($device);
302 This returns the size of the device in bytes.
304 See also C<$h-E<gt>blockdev_getsz>.
306 This uses the L<blockdev(8)> command.
308 =item $sectorsize = $h->blockdev_getss ($device);
310 This returns the size of sectors on a block device.
311 Usually 512, but can be larger for modern devices.
313 (Note, this is not the size in sectors, use C<$h-E<gt>blockdev_getsz>
316 This uses the L<blockdev(8)> command.
318 =item $sizeinsectors = $h->blockdev_getsz ($device);
320 This returns the size of the device in units of 512-byte sectors
321 (even if the sectorsize isn't 512 bytes ... weird).
323 See also C<$h-E<gt>blockdev_getss> for the real sector size of
324 the device, and C<$h-E<gt>blockdev_getsize64> for the more
325 useful I<size in bytes>.
327 This uses the L<blockdev(8)> command.
329 =item $h->blockdev_rereadpt ($device);
331 Reread the partition table on C<device>.
333 This uses the L<blockdev(8)> command.
335 =item $h->blockdev_setbsz ($device, $blocksize);
337 This sets the block size of a device.
339 (Note this is different from both I<size in blocks> and
340 I<filesystem block size>).
342 This uses the L<blockdev(8)> command.
344 =item $h->blockdev_setro ($device);
346 Sets the block device named C<device> to read-only.
348 This uses the L<blockdev(8)> command.
350 =item $h->blockdev_setrw ($device);
352 Sets the block device named C<device> to read-write.
354 This uses the L<blockdev(8)> command.
356 =item $content = $h->cat ($path);
358 Return the contents of the file named C<path>.
360 Note that this function cannot correctly handle binary files
361 (specifically, files containing C<\0> character which is treated
362 as end of string). For those you need to use the C<$h-E<gt>download>
363 function which has a more complex interface.
365 Because of the message protocol, there is a transfer limit
366 of somewhere between 2MB and 4MB. To transfer large files you should use
369 =item $checksum = $h->checksum ($csumtype, $path);
371 This call computes the MD5, SHAx or CRC checksum of the
374 The type of checksum to compute is given by the C<csumtype>
375 parameter which must have one of the following values:
381 Compute the cyclic redundancy check (CRC) specified by POSIX
382 for the C<cksum> command.
386 Compute the MD5 hash (using the C<md5sum> program).
390 Compute the SHA1 hash (using the C<sha1sum> program).
394 Compute the SHA224 hash (using the C<sha224sum> program).
398 Compute the SHA256 hash (using the C<sha256sum> program).
402 Compute the SHA384 hash (using the C<sha384sum> program).
406 Compute the SHA512 hash (using the C<sha512sum> program).
410 The checksum is returned as a printable string.
412 =item $h->chmod ($mode, $path);
414 Change the mode (permissions) of C<path> to C<mode>. Only
415 numeric modes are supported.
417 =item $h->chown ($owner, $group, $path);
419 Change the file owner to C<owner> and group to C<group>.
421 Only numeric uid and gid are supported. If you want to use
422 names, you will need to locate and parse the password file
423 yourself (Augeas support makes this relatively easy).
425 =item $output = $h->command (\@arguments);
427 This call runs a command from the guest filesystem. The
428 filesystem must be mounted, and must contain a compatible
429 operating system (ie. something Linux, with the same
430 or compatible processor architecture).
432 The single parameter is an argv-style list of arguments.
433 The first element is the name of the program to run.
434 Subsequent elements are parameters. The list must be
435 non-empty (ie. must contain a program name). Note that
436 the command runs directly, and is I<not> invoked via
437 the shell (see C<$h-E<gt>sh>).
439 The return value is anything printed to I<stdout> by
442 If the command returns a non-zero exit status, then
443 this function returns an error message. The error message
444 string is the content of I<stderr> from the command.
446 The C<$PATH> environment variable will contain at least
447 C</usr/bin> and C</bin>. If you require a program from
448 another location, you should provide the full path in the
451 Shared libraries and data files required by the program
452 must be available on filesystems which are mounted in the
453 correct places. It is the caller's responsibility to ensure
454 all filesystems that are needed are mounted at the right
457 Because of the message protocol, there is a transfer limit
458 of somewhere between 2MB and 4MB. To transfer large files you should use
461 =item @lines = $h->command_lines (\@arguments);
463 This is the same as C<$h-E<gt>command>, but splits the
464 result into a list of lines.
466 See also: C<$h-E<gt>sh_lines>
468 Because of the message protocol, there is a transfer limit
469 of somewhere between 2MB and 4MB. To transfer large files you should use
472 =item $h->config ($qemuparam, $qemuvalue);
474 This can be used to add arbitrary qemu command line parameters
475 of the form C<-param value>. Actually it's not quite arbitrary - we
476 prevent you from setting some parameters which would interfere with
477 parameters that we use.
479 The first character of C<param> string must be a C<-> (dash).
481 C<value> can be NULL.
483 =item $h->cp ($src, $dest);
485 This copies a file from C<src> to C<dest> where C<dest> is
486 either a destination filename or destination directory.
488 =item $h->cp_a ($src, $dest);
490 This copies a file or directory from C<src> to C<dest>
491 recursively using the C<cp -a> command.
493 =item $result = $h->debug ($subcmd, \@extraargs);
495 The C<$h-E<gt>debug> command exposes some internals of
496 C<guestfsd> (the guestfs daemon) that runs inside the
499 There is no comprehensive help for this command. You have
500 to look at the file C<daemon/debug.c> in the libguestfs source
501 to find out what you can do.
503 =item $kmsgs = $h->dmesg ();
505 This returns the kernel messages (C<dmesg> output) from
506 the guest kernel. This is sometimes useful for extended
507 debugging of problems.
509 Another way to get the same information is to enable
510 verbose messages with C<$h-E<gt>set_verbose> or by setting
511 the environment variable C<LIBGUESTFS_DEBUG=1> before
514 =item $h->download ($remotefilename, $filename);
516 Download file C<remotefilename> and save it as C<filename>
517 on the local machine.
519 C<filename> can also be a named pipe.
521 See also C<$h-E<gt>upload>, C<$h-E<gt>cat>.
523 =item $h->drop_caches ($whattodrop);
525 This instructs the guest kernel to drop its page cache,
526 and/or dentries and inode caches. The parameter C<whattodrop>
527 tells the kernel what precisely to drop, see
528 L<http://linux-mm.org/Drop_Caches>
530 Setting C<whattodrop> to 3 should drop everything.
532 This automatically calls L<sync(2)> before the operation,
533 so that the maximum guest memory is freed.
535 =item $h->e2fsck_f ($device);
537 This runs C<e2fsck -p -f device>, ie. runs the ext2/ext3
538 filesystem checker on C<device>, noninteractively (C<-p>),
539 even if the filesystem appears to be clean (C<-f>).
541 This command is only needed because of C<$h-E<gt>resize2fs>
542 (q.v.). Normally you should use C<$h-E<gt>fsck>.
544 =item $h->end_busy ();
546 This sets the state to C<READY>, or if in C<CONFIG> then it leaves the
547 state as is. This is only used when implementing
548 actions using the low-level API.
550 For more information on states, see L<guestfs(3)>.
552 =item $equality = $h->equal ($file1, $file2);
554 This compares the two files C<file1> and C<file2> and returns
555 true if their content is exactly equal, or false otherwise.
557 The external L<cmp(1)> program is used for the comparison.
559 =item $existsflag = $h->exists ($path);
561 This returns C<true> if and only if there is a file, directory
562 (or anything) with the given C<path> name.
564 See also C<$h-E<gt>is_file>, C<$h-E<gt>is_dir>, C<$h-E<gt>stat>.
566 =item $description = $h->file ($path);
568 This call uses the standard L<file(1)> command to determine
569 the type or contents of the file. This also works on devices,
570 for example to find out whether a partition contains a filesystem.
572 The exact command which runs is C<file -bsL path>. Note in
573 particular that the filename is not prepended to the output
576 =item @names = $h->find ($directory);
578 This command lists out all files and directories, recursively,
579 starting at C<directory>. It is essentially equivalent to
580 running the shell command C<find directory -print> but some
581 post-processing happens on the output, described below.
583 This returns a list of strings I<without any prefix>. Thus
584 if the directory structure was:
590 then the returned list from C<$h-E<gt>find> C</tmp> would be
598 If C<directory> is not a directory, then this command returns
601 The returned list is sorted.
603 =item $status = $h->fsck ($fstype, $device);
605 This runs the filesystem checker (fsck) on C<device> which
606 should have filesystem type C<fstype>.
608 The returned integer is the status. See L<fsck(8)> for the
609 list of status codes from C<fsck>.
617 Multiple status codes can be summed together.
621 A non-zero return code can mean "success", for example if
622 errors have been corrected on the filesystem.
626 Checking or repairing NTFS volumes is not supported
631 This command is entirely equivalent to running C<fsck -a -t fstype device>.
633 =item $append = $h->get_append ();
635 Return the additional kernel options which are added to the
636 guest kernel command line.
638 If C<NULL> then no options are added.
640 =item $autosync = $h->get_autosync ();
642 Get the autosync flag.
644 =item $label = $h->get_e2label ($device);
646 This returns the ext2/3/4 filesystem label of the filesystem on
649 =item $uuid = $h->get_e2uuid ($device);
651 This returns the ext2/3/4 filesystem UUID of the filesystem on
654 =item $path = $h->get_path ();
656 Return the current search path.
658 This is always non-NULL. If it wasn't set already, then this will
659 return the default path.
661 =item $qemu = $h->get_qemu ();
663 Return the current qemu binary.
665 This is always non-NULL. If it wasn't set already, then this will
666 return the default qemu binary name.
668 =item $state = $h->get_state ();
670 This returns the current state as an opaque integer. This is
671 only useful for printing debug and internal error messages.
673 For more information on states, see L<guestfs(3)>.
675 =item $verbose = $h->get_verbose ();
677 This returns the verbose messages flag.
679 =item @paths = $h->glob_expand ($pattern);
681 This command searches for all the pathnames matching
682 C<pattern> according to the wildcard expansion rules
685 If no paths match, then this returns an empty list
686 (note: not an error).
688 It is just a wrapper around the C L<glob(3)> function
689 with flags C<GLOB_MARK|GLOB_BRACE>.
690 See that manual page for more details.
692 =item $h->grub_install ($root, $device);
694 This command installs GRUB (the Grand Unified Bootloader) on
695 C<device>, with the root directory being C<root>.
697 =item @lines = $h->head ($path);
699 This command returns up to the first 10 lines of a file as
702 Because of the message protocol, there is a transfer limit
703 of somewhere between 2MB and 4MB. To transfer large files you should use
706 =item @lines = $h->head_n ($nrlines, $path);
708 If the parameter C<nrlines> is a positive number, this returns the first
709 C<nrlines> lines of the file C<path>.
711 If the parameter C<nrlines> is a negative number, this returns lines
712 from the file C<path>, excluding the last C<nrlines> lines.
714 If the parameter C<nrlines> is zero, this returns an empty list.
716 Because of the message protocol, there is a transfer limit
717 of somewhere between 2MB and 4MB. To transfer large files you should use
720 =item $dump = $h->hexdump ($path);
722 This runs C<hexdump -C> on the given C<path>. The result is
723 the human-readable, canonical hex dump of the file.
725 Because of the message protocol, there is a transfer limit
726 of somewhere between 2MB and 4MB. To transfer large files you should use
729 =item $busy = $h->is_busy ();
731 This returns true iff this handle is busy processing a command
732 (in the C<BUSY> state).
734 For more information on states, see L<guestfs(3)>.
736 =item $config = $h->is_config ();
738 This returns true iff this handle is being configured
739 (in the C<CONFIG> state).
741 For more information on states, see L<guestfs(3)>.
743 =item $dirflag = $h->is_dir ($path);
745 This returns C<true> if and only if there is a directory
746 with the given C<path> name. Note that it returns false for
747 other objects like files.
749 See also C<$h-E<gt>stat>.
751 =item $fileflag = $h->is_file ($path);
753 This returns C<true> if and only if there is a file
754 with the given C<path> name. Note that it returns false for
755 other objects like directories.
757 See also C<$h-E<gt>stat>.
759 =item $launching = $h->is_launching ();
761 This returns true iff this handle is launching the subprocess
762 (in the C<LAUNCHING> state).
764 For more information on states, see L<guestfs(3)>.
766 =item $ready = $h->is_ready ();
768 This returns true iff this handle is ready to accept commands
769 (in the C<READY> state).
771 For more information on states, see L<guestfs(3)>.
773 =item $h->kill_subprocess ();
775 This kills the qemu subprocess. You should never need to call this.
779 Internally libguestfs is implemented by running a virtual machine
782 You should call this after configuring the handle
783 (eg. adding drives) but before performing any actions.
785 =item @devices = $h->list_devices ();
787 List all the block devices.
789 The full block device names are returned, eg. C</dev/sda>
791 =item @partitions = $h->list_partitions ();
793 List all the partitions detected on all block devices.
795 The full partition device names are returned, eg. C</dev/sda1>
797 This does not return logical volumes. For that you will need to
800 =item $listing = $h->ll ($directory);
802 List the files in C<directory> (relative to the root directory,
803 there is no cwd) in the format of 'ls -la'.
805 This command is mostly useful for interactive sessions. It
806 is I<not> intended that you try to parse the output string.
808 =item @listing = $h->ls ($directory);
810 List the files in C<directory> (relative to the root directory,
811 there is no cwd). The '.' and '..' entries are not returned, but
812 hidden files are shown.
814 This command is mostly useful for interactive sessions. Programs
815 should probably use C<$h-E<gt>readdir> instead.
817 =item %statbuf = $h->lstat ($path);
819 Returns file information for the given C<path>.
821 This is the same as C<$h-E<gt>stat> except that if C<path>
822 is a symbolic link, then the link is stat-ed, not the file it
825 This is the same as the C<lstat(2)> system call.
827 =item $h->lvcreate ($logvol, $volgroup, $mbytes);
829 This creates an LVM volume group called C<logvol>
830 on the volume group C<volgroup>, with C<size> megabytes.
832 =item $h->lvm_remove_all ();
834 This command removes all LVM logical volumes, volume groups
835 and physical volumes.
837 B<This command is dangerous. Without careful use you
838 can easily destroy all your data>.
840 =item $h->lvremove ($device);
842 Remove an LVM logical volume C<device>, where C<device> is
843 the path to the LV, such as C</dev/VG/LV>.
845 You can also remove all LVs in a volume group by specifying
846 the VG name, C</dev/VG>.
848 =item $h->lvresize ($device, $mbytes);
850 This resizes (expands or shrinks) an existing LVM logical
851 volume to C<mbytes>. When reducing, data in the reduced part
854 =item @logvols = $h->lvs ();
856 List all the logical volumes detected. This is the equivalent
857 of the L<lvs(8)> command.
859 This returns a list of the logical volume device names
860 (eg. C</dev/VolGroup00/LogVol00>).
862 See also C<$h-E<gt>lvs_full>.
864 =item @logvols = $h->lvs_full ();
866 List all the logical volumes detected. This is the equivalent
867 of the L<lvs(8)> command. The "full" version includes all fields.
869 =item $h->mkdir ($path);
871 Create a directory named C<path>.
873 =item $h->mkdir_p ($path);
875 Create a directory named C<path>, creating any parent directories
876 as necessary. This is like the C<mkdir -p> shell command.
878 =item $dir = $h->mkdtemp ($template);
880 This command creates a temporary directory. The
881 C<template> parameter should be a full pathname for the
882 temporary directory name with the final six characters being
885 For example: "/tmp/myprogXXXXXX" or "/Temp/myprogXXXXXX",
886 the second one being suitable for Windows filesystems.
888 The name of the temporary directory that was created
891 The temporary directory is created with mode 0700
892 and is owned by root.
894 The caller is responsible for deleting the temporary
895 directory and its contents after use.
897 See also: L<mkdtemp(3)>
899 =item $h->mkfs ($fstype, $device);
901 This creates a filesystem on C<device> (usually a partition
902 or LVM logical volume). The filesystem type is C<fstype>, for
905 =item $h->mount ($device, $mountpoint);
907 Mount a guest disk at a position in the filesystem. Block devices
908 are named C</dev/sda>, C</dev/sdb> and so on, as they were added to
909 the guest. If those block devices contain partitions, they will have
910 the usual names (eg. C</dev/sda1>). Also LVM C</dev/VG/LV>-style
913 The rules are the same as for L<mount(2)>: A filesystem must
914 first be mounted on C</> before others can be mounted. Other
915 filesystems can only be mounted on directories which already
918 The mounted filesystem is writable, if we have sufficient permissions
919 on the underlying device.
921 The filesystem options C<sync> and C<noatime> are set with this
922 call, in order to improve reliability.
924 =item $h->mount_options ($options, $device, $mountpoint);
926 This is the same as the C<$h-E<gt>mount> command, but it
927 allows you to set the mount options as for the
928 L<mount(8)> I<-o> flag.
930 =item $h->mount_ro ($device, $mountpoint);
932 This is the same as the C<$h-E<gt>mount> command, but it
933 mounts the filesystem with the read-only (I<-o ro>) flag.
935 =item $h->mount_vfs ($options, $vfstype, $device, $mountpoint);
937 This is the same as the C<$h-E<gt>mount> command, but it
938 allows you to set both the mount options and the vfstype
939 as for the L<mount(8)> I<-o> and I<-t> flags.
941 =item @devices = $h->mounts ();
943 This returns the list of currently mounted filesystems. It returns
944 the list of devices (eg. C</dev/sda1>, C</dev/VG/LV>).
946 Some internal mounts are not shown.
948 =item $h->mv ($src, $dest);
950 This moves a file from C<src> to C<dest> where C<dest> is
951 either a destination filename or destination directory.
953 =item $status = $h->ntfs_3g_probe ($rw, $device);
955 This command runs the L<ntfs-3g.probe(8)> command which probes
956 an NTFS C<device> for mountability. (Not all NTFS volumes can
957 be mounted read-write, and some cannot be mounted at all).
959 C<rw> is a boolean flag. Set it to true if you want to test
960 if the volume can be mounted read-write. Set it to false if
961 you want to test if the volume can be mounted read-only.
963 The return value is an integer which C<0> if the operation
964 would succeed, or some non-zero value documented in the
965 L<ntfs-3g.probe(8)> manual page.
967 =item $h->ping_daemon ();
969 This is a test probe into the guestfs daemon running inside
970 the qemu subprocess. Calling this function checks that the
971 daemon responds to the ping message, without affecting the daemon
972 or attached block device(s) in any other way.
974 =item $h->pvcreate ($device);
976 This creates an LVM physical volume on the named C<device>,
977 where C<device> should usually be a partition name such
980 =item $h->pvremove ($device);
982 This wipes a physical volume C<device> so that LVM will no longer
985 The implementation uses the C<pvremove> command which refuses to
986 wipe physical volumes that contain any volume groups, so you have
987 to remove those first.
989 =item $h->pvresize ($device);
991 This resizes (expands or shrinks) an existing LVM physical
992 volume to match the new size of the underlying device.
994 =item @physvols = $h->pvs ();
996 List all the physical volumes detected. This is the equivalent
997 of the L<pvs(8)> command.
999 This returns a list of just the device names that contain
1000 PVs (eg. C</dev/sda2>).
1002 See also C<$h-E<gt>pvs_full>.
1004 =item @physvols = $h->pvs_full ();
1006 List all the physical volumes detected. This is the equivalent
1007 of the L<pvs(8)> command. The "full" version includes all fields.
1009 =item @lines = $h->read_lines ($path);
1011 Return the contents of the file named C<path>.
1013 The file contents are returned as a list of lines. Trailing
1014 C<LF> and C<CRLF> character sequences are I<not> returned.
1016 Note that this function cannot correctly handle binary files
1017 (specifically, files containing C<\0> character which is treated
1018 as end of line). For those you need to use the C<$h-E<gt>read_file>
1019 function which has a more complex interface.
1021 =item $h->resize2fs ($device);
1023 This resizes an ext2 or ext3 filesystem to match the size of
1024 the underlying device.
1026 I<Note:> It is sometimes required that you run C<$h-E<gt>e2fsck_f>
1027 on the C<device> before calling this command. For unknown reasons
1028 C<resize2fs> sometimes gives an error about this and sometimes not.
1029 In any case, it is always safe to call C<$h-E<gt>e2fsck_f> before
1030 calling this function.
1032 =item $h->rm ($path);
1034 Remove the single file C<path>.
1036 =item $h->rm_rf ($path);
1038 Remove the file or directory C<path>, recursively removing the
1039 contents if its a directory. This is like the C<rm -rf> shell
1042 =item $h->rmdir ($path);
1044 Remove the single directory C<path>.
1046 =item $h->scrub_device ($device);
1048 This command writes patterns over C<device> to make data retrieval
1051 It is an interface to the L<scrub(1)> program. See that
1052 manual page for more details.
1054 B<This command is dangerous. Without careful use you
1055 can easily destroy all your data>.
1057 =item $h->scrub_file ($file);
1059 This command writes patterns over a file to make data retrieval
1062 The file is I<removed> after scrubbing.
1064 It is an interface to the L<scrub(1)> program. See that
1065 manual page for more details.
1067 =item $h->scrub_freespace ($dir);
1069 This command creates the directory C<dir> and then fills it
1070 with files until the filesystem is full, and scrubs the files
1071 as for C<$h-E<gt>scrub_file>, and deletes them.
1072 The intention is to scrub any free space on the partition
1075 It is an interface to the L<scrub(1)> program. See that
1076 manual page for more details.
1078 =item $h->set_append ($append);
1080 This function is used to add additional options to the
1081 guest kernel command line.
1083 The default is C<NULL> unless overridden by setting
1084 C<LIBGUESTFS_APPEND> environment variable.
1086 Setting C<append> to C<NULL> means I<no> additional options
1087 are passed (libguestfs always adds a few of its own).
1089 =item $h->set_autosync ($autosync);
1091 If C<autosync> is true, this enables autosync. Libguestfs will make a
1092 best effort attempt to run C<$h-E<gt>umount_all> followed by
1093 C<$h-E<gt>sync> when the handle is closed
1094 (also if the program exits without closing handles).
1096 This is disabled by default (except in guestfish where it is
1097 enabled by default).
1099 =item $h->set_busy ();
1101 This sets the state to C<BUSY>. This is only used when implementing
1102 actions using the low-level API.
1104 For more information on states, see L<guestfs(3)>.
1106 =item $h->set_e2label ($device, $label);
1108 This sets the ext2/3/4 filesystem label of the filesystem on
1109 C<device> to C<label>. Filesystem labels are limited to
1112 You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2label>
1113 to return the existing label on a filesystem.
1115 =item $h->set_e2uuid ($device, $uuid);
1117 This sets the ext2/3/4 filesystem UUID of the filesystem on
1118 C<device> to C<uuid>. The format of the UUID and alternatives
1119 such as C<clear>, C<random> and C<time> are described in the
1120 L<tune2fs(8)> manpage.
1122 You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2uuid>
1123 to return the existing UUID of a filesystem.
1125 =item $h->set_path ($path);
1127 Set the path that libguestfs searches for kernel and initrd.img.
1129 The default is C<$libdir/guestfs> unless overridden by setting
1130 C<LIBGUESTFS_PATH> environment variable.
1132 Setting C<path> to C<NULL> restores the default path.
1134 =item $h->set_qemu ($qemu);
1136 Set the qemu binary that we will use.
1138 The default is chosen when the library was compiled by the
1141 You can also override this by setting the C<LIBGUESTFS_QEMU>
1142 environment variable.
1144 Setting C<qemu> to C<NULL> restores the default qemu binary.
1146 =item $h->set_ready ();
1148 This sets the state to C<READY>. This is only used when implementing
1149 actions using the low-level API.
1151 For more information on states, see L<guestfs(3)>.
1153 =item $h->set_verbose ($verbose);
1155 If C<verbose> is true, this turns on verbose messages (to C<stderr>).
1157 Verbose messages are disabled unless the environment variable
1158 C<LIBGUESTFS_DEBUG> is defined and set to C<1>.
1160 =item $h->sfdisk ($device, $cyls, $heads, $sectors, \@lines);
1162 This is a direct interface to the L<sfdisk(8)> program for creating
1163 partitions on block devices.
1165 C<device> should be a block device, for example C</dev/sda>.
1167 C<cyls>, C<heads> and C<sectors> are the number of cylinders, heads
1168 and sectors on the device, which are passed directly to sfdisk as
1169 the I<-C>, I<-H> and I<-S> parameters. If you pass C<0> for any
1170 of these, then the corresponding parameter is omitted. Usually for
1171 'large' disks, you can just pass C<0> for these, but for small
1172 (floppy-sized) disks, sfdisk (or rather, the kernel) cannot work
1173 out the right geometry and you will need to tell it.
1175 C<lines> is a list of lines that we feed to C<sfdisk>. For more
1176 information refer to the L<sfdisk(8)> manpage.
1178 To create a single partition occupying the whole disk, you would
1179 pass C<lines> as a single element list, when the single element being
1180 the string C<,> (comma).
1182 See also: C<$h-E<gt>sfdisk_l>, C<$h-E<gt>sfdisk_N>
1184 B<This command is dangerous. Without careful use you
1185 can easily destroy all your data>.
1187 =item $h->sfdisk_N ($device, $partnum, $cyls, $heads, $sectors, $line);
1189 This runs L<sfdisk(8)> option to modify just the single
1190 partition C<n> (note: C<n> counts from 1).
1192 For other parameters, see C<$h-E<gt>sfdisk>. You should usually
1193 pass C<0> for the cyls/heads/sectors parameters.
1195 B<This command is dangerous. Without careful use you
1196 can easily destroy all your data>.
1198 =item $partitions = $h->sfdisk_disk_geometry ($device);
1200 This displays the disk geometry of C<device> read from the
1201 partition table. Especially in the case where the underlying
1202 block device has been resized, this can be different from the
1203 kernel's idea of the geometry (see C<$h-E<gt>sfdisk_kernel_geometry>).
1205 The result is in human-readable format, and not designed to
1208 =item $partitions = $h->sfdisk_kernel_geometry ($device);
1210 This displays the kernel's idea of the geometry of C<device>.
1212 The result is in human-readable format, and not designed to
1215 =item $partitions = $h->sfdisk_l ($device);
1217 This displays the partition table on C<device>, in the
1218 human-readable output of the L<sfdisk(8)> command. It is
1219 not intended to be parsed.
1221 =item $output = $h->sh ($command);
1223 This call runs a command from the guest filesystem via the
1226 This is like C<$h-E<gt>command>, but passes the command to:
1228 /bin/sh -c "command"
1230 Depending on the guest's shell, this usually results in
1231 wildcards being expanded, shell expressions being interpolated
1234 All the provisos about C<$h-E<gt>command> apply to this call.
1236 =item @lines = $h->sh_lines ($command);
1238 This is the same as C<$h-E<gt>sh>, but splits the result
1239 into a list of lines.
1241 See also: C<$h-E<gt>command_lines>
1243 =item $h->sleep ($secs);
1245 Sleep for C<secs> seconds.
1247 =item %statbuf = $h->stat ($path);
1249 Returns file information for the given C<path>.
1251 This is the same as the C<stat(2)> system call.
1253 =item %statbuf = $h->statvfs ($path);
1255 Returns file system statistics for any mounted file system.
1256 C<path> should be a file or directory in the mounted file system
1257 (typically it is the mount point itself, but it doesn't need to be).
1259 This is the same as the C<statvfs(2)> system call.
1261 =item @stringsout = $h->strings ($path);
1263 This runs the L<strings(1)> command on a file and returns
1264 the list of printable strings found.
1266 Because of the message protocol, there is a transfer limit
1267 of somewhere between 2MB and 4MB. To transfer large files you should use
1270 =item @stringsout = $h->strings_e ($encoding, $path);
1272 This is like the C<$h-E<gt>strings> command, but allows you to
1273 specify the encoding.
1275 See the L<strings(1)> manpage for the full list of encodings.
1277 Commonly useful encodings are C<l> (lower case L) which will
1278 show strings inside Windows/x86 files.
1280 The returned strings are transcoded to UTF-8.
1282 Because of the message protocol, there is a transfer limit
1283 of somewhere between 2MB and 4MB. To transfer large files you should use
1288 This syncs the disk, so that any writes are flushed through to the
1289 underlying disk image.
1291 You should always call this if you have modified a disk image, before
1294 =item @lines = $h->tail ($path);
1296 This command returns up to the last 10 lines of a file as
1299 Because of the message protocol, there is a transfer limit
1300 of somewhere between 2MB and 4MB. To transfer large files you should use
1303 =item @lines = $h->tail_n ($nrlines, $path);
1305 If the parameter C<nrlines> is a positive number, this returns the last
1306 C<nrlines> lines of the file C<path>.
1308 If the parameter C<nrlines> is a negative number, this returns lines
1309 from the file C<path>, starting with the C<-nrlines>th line.
1311 If the parameter C<nrlines> is zero, this returns an empty list.
1313 Because of the message protocol, there is a transfer limit
1314 of somewhere between 2MB and 4MB. To transfer large files you should use
1317 =item $h->tar_in ($tarfile, $directory);
1319 This command uploads and unpacks local file C<tarfile> (an
1320 I<uncompressed> tar file) into C<directory>.
1322 To upload a compressed tarball, use C<$h-E<gt>tgz_in>.
1324 =item $h->tar_out ($directory, $tarfile);
1326 This command packs the contents of C<directory> and downloads
1327 it to local file C<tarfile>.
1329 To download a compressed tarball, use C<$h-E<gt>tgz_out>.
1331 =item $h->tgz_in ($tarball, $directory);
1333 This command uploads and unpacks local file C<tarball> (a
1334 I<gzip compressed> tar file) into C<directory>.
1336 To upload an uncompressed tarball, use C<$h-E<gt>tar_in>.
1338 =item $h->tgz_out ($directory, $tarball);
1340 This command packs the contents of C<directory> and downloads
1341 it to local file C<tarball>.
1343 To download an uncompressed tarball, use C<$h-E<gt>tar_out>.
1345 =item $h->touch ($path);
1347 Touch acts like the L<touch(1)> command. It can be used to
1348 update the timestamps on a file, or, if the file does not exist,
1349 to create a new zero-length file.
1351 =item %superblock = $h->tune2fs_l ($device);
1353 This returns the contents of the ext2, ext3 or ext4 filesystem
1354 superblock on C<device>.
1356 It is the same as running C<tune2fs -l device>. See L<tune2fs(8)>
1357 manpage for more details. The list of fields returned isn't
1358 clearly defined, and depends on both the version of C<tune2fs>
1359 that libguestfs was built against, and the filesystem itself.
1361 =item $h->umount ($pathordevice);
1363 This unmounts the given filesystem. The filesystem may be
1364 specified either by its mountpoint (path) or the device which
1365 contains the filesystem.
1367 =item $h->umount_all ();
1369 This unmounts all mounted filesystems.
1371 Some internal mounts are not unmounted by this call.
1373 =item $h->upload ($filename, $remotefilename);
1375 Upload local file C<filename> to C<remotefilename> on the
1378 C<filename> can also be a named pipe.
1380 See also C<$h-E<gt>download>.
1382 =item $h->vg_activate ($activate, \@volgroups);
1384 This command activates or (if C<activate> is false) deactivates
1385 all logical volumes in the listed volume groups C<volgroups>.
1386 If activated, then they are made known to the
1387 kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
1388 then those devices disappear.
1390 This command is the same as running C<vgchange -a y|n volgroups...>
1392 Note that if C<volgroups> is an empty list then B<all> volume groups
1393 are activated or deactivated.
1395 =item $h->vg_activate_all ($activate);
1397 This command activates or (if C<activate> is false) deactivates
1398 all logical volumes in all volume groups.
1399 If activated, then they are made known to the
1400 kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
1401 then those devices disappear.
1403 This command is the same as running C<vgchange -a y|n>
1405 =item $h->vgcreate ($volgroup, \@physvols);
1407 This creates an LVM volume group called C<volgroup>
1408 from the non-empty list of physical volumes C<physvols>.
1410 =item $h->vgremove ($vgname);
1412 Remove an LVM volume group C<vgname>, (for example C<VG>).
1414 This also forcibly removes all logical volumes in the volume
1417 =item @volgroups = $h->vgs ();
1419 List all the volumes groups detected. This is the equivalent
1420 of the L<vgs(8)> command.
1422 This returns a list of just the volume group names that were
1423 detected (eg. C<VolGroup00>).
1425 See also C<$h-E<gt>vgs_full>.
1427 =item @volgroups = $h->vgs_full ();
1429 List all the volumes groups detected. This is the equivalent
1430 of the L<vgs(8)> command. The "full" version includes all fields.
1432 =item $h->wait_ready ();
1434 Internally libguestfs is implemented by running a virtual machine
1437 You should call this after C<$h-E<gt>launch> to wait for the launch
1440 =item $chars = $h->wc_c ($path);
1442 This command counts the characters in a file, using the
1443 C<wc -c> external command.
1445 =item $lines = $h->wc_l ($path);
1447 This command counts the lines in a file, using the
1448 C<wc -l> external command.
1450 =item $words = $h->wc_w ($path);
1452 This command counts the words in a file, using the
1453 C<wc -w> external command.
1455 =item $h->write_file ($path, $content, $size);
1457 This call creates a file called C<path>. The contents of the
1458 file is the string C<content> (which can contain any 8 bit data),
1459 with length C<size>.
1461 As a special case, if C<size> is C<0>
1462 then the length is calculated using C<strlen> (so in this case
1463 the content cannot contain embedded ASCII NULs).
1465 I<NB.> Owing to a bug, writing content containing ASCII NUL
1466 characters does I<not> work, even if the length is specified.
1467 We hope to resolve this bug in a future version. In the meantime
1468 use C<$h-E<gt>upload>.
1470 Because of the message protocol, there is a transfer limit
1471 of somewhere between 2MB and 4MB. To transfer large files you should use
1474 =item $h->zero ($device);
1476 This command writes zeroes over the first few blocks of C<device>.
1478 How many blocks are zeroed isn't specified (but it's I<not> enough
1479 to securely wipe the device). It should be sufficient to remove
1480 any partition tables, filesystem superblocks and so on.
1482 See also: C<$h-E<gt>scrub_device>.
1484 =item $h->zerofree ($device);
1486 This runs the I<zerofree> program on C<device>. This program
1487 claims to zero unused inodes and disk blocks on an ext2/3
1488 filesystem, thus making it possible to compress the filesystem
1491 You should B<not> run this program if the filesystem is
1494 It is possible that using this program can damage the filesystem
1495 or data on the filesystem.
1505 Copyright (C) 2009 Red Hat Inc.
1509 Please see the file COPYING.LIB for the full license.
1513 L<guestfs(3)>, L<guestfish(1)>.