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2 # WARNING: THIS FILE IS GENERATED BY 'src/generator.ml'.
3 # ANY CHANGES YOU MAKE TO THIS FILE WILL BE LOST.
5 # Copyright (C) 2009 Red Hat Inc.
7 # This library is free software; you can redistribute it and/or
8 # modify it under the terms of the GNU Lesser General Public
9 # License as published by the Free Software Foundation; either
10 # version 2 of the License, or (at your option) any later version.
12 # This library is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 # Lesser General Public License for more details.
17 # You should have received a copy of the GNU Lesser General Public
18 # License along with this library; if not, write to the Free Software
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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 $output = $h->df ();
505 This command runs the C<df> command to report disk space used.
507 This command is mostly useful for interactive sessions. It
508 is I<not> intended that you try to parse the output string.
509 Use C<statvfs> from programs.
511 =item $output = $h->df_h ();
513 This command runs the C<df -h> command to report disk space used
514 in human-readable format.
516 This command is mostly useful for interactive sessions. It
517 is I<not> intended that you try to parse the output string.
518 Use C<statvfs> from programs.
520 =item $kmsgs = $h->dmesg ();
522 This returns the kernel messages (C<dmesg> output) from
523 the guest kernel. This is sometimes useful for extended
524 debugging of problems.
526 Another way to get the same information is to enable
527 verbose messages with C<$h-E<gt>set_verbose> or by setting
528 the environment variable C<LIBGUESTFS_DEBUG=1> before
531 =item $h->download ($remotefilename, $filename);
533 Download file C<remotefilename> and save it as C<filename>
534 on the local machine.
536 C<filename> can also be a named pipe.
538 See also C<$h-E<gt>upload>, C<$h-E<gt>cat>.
540 =item $h->drop_caches ($whattodrop);
542 This instructs the guest kernel to drop its page cache,
543 and/or dentries and inode caches. The parameter C<whattodrop>
544 tells the kernel what precisely to drop, see
545 L<http://linux-mm.org/Drop_Caches>
547 Setting C<whattodrop> to 3 should drop everything.
549 This automatically calls L<sync(2)> before the operation,
550 so that the maximum guest memory is freed.
552 =item $h->e2fsck_f ($device);
554 This runs C<e2fsck -p -f device>, ie. runs the ext2/ext3
555 filesystem checker on C<device>, noninteractively (C<-p>),
556 even if the filesystem appears to be clean (C<-f>).
558 This command is only needed because of C<$h-E<gt>resize2fs>
559 (q.v.). Normally you should use C<$h-E<gt>fsck>.
561 =item $h->end_busy ();
563 This sets the state to C<READY>, or if in C<CONFIG> then it leaves the
564 state as is. This is only used when implementing
565 actions using the low-level API.
567 For more information on states, see L<guestfs(3)>.
569 =item $equality = $h->equal ($file1, $file2);
571 This compares the two files C<file1> and C<file2> and returns
572 true if their content is exactly equal, or false otherwise.
574 The external L<cmp(1)> program is used for the comparison.
576 =item $existsflag = $h->exists ($path);
578 This returns C<true> if and only if there is a file, directory
579 (or anything) with the given C<path> name.
581 See also C<$h-E<gt>is_file>, C<$h-E<gt>is_dir>, C<$h-E<gt>stat>.
583 =item $description = $h->file ($path);
585 This call uses the standard L<file(1)> command to determine
586 the type or contents of the file. This also works on devices,
587 for example to find out whether a partition contains a filesystem.
589 The exact command which runs is C<file -bsL path>. Note in
590 particular that the filename is not prepended to the output
593 =item @names = $h->find ($directory);
595 This command lists out all files and directories, recursively,
596 starting at C<directory>. It is essentially equivalent to
597 running the shell command C<find directory -print> but some
598 post-processing happens on the output, described below.
600 This returns a list of strings I<without any prefix>. Thus
601 if the directory structure was:
607 then the returned list from C<$h-E<gt>find> C</tmp> would be
615 If C<directory> is not a directory, then this command returns
618 The returned list is sorted.
620 =item $status = $h->fsck ($fstype, $device);
622 This runs the filesystem checker (fsck) on C<device> which
623 should have filesystem type C<fstype>.
625 The returned integer is the status. See L<fsck(8)> for the
626 list of status codes from C<fsck>.
634 Multiple status codes can be summed together.
638 A non-zero return code can mean "success", for example if
639 errors have been corrected on the filesystem.
643 Checking or repairing NTFS volumes is not supported
648 This command is entirely equivalent to running C<fsck -a -t fstype device>.
650 =item $append = $h->get_append ();
652 Return the additional kernel options which are added to the
653 guest kernel command line.
655 If C<NULL> then no options are added.
657 =item $autosync = $h->get_autosync ();
659 Get the autosync flag.
661 =item $label = $h->get_e2label ($device);
663 This returns the ext2/3/4 filesystem label of the filesystem on
666 =item $uuid = $h->get_e2uuid ($device);
668 This returns the ext2/3/4 filesystem UUID of the filesystem on
671 =item $path = $h->get_path ();
673 Return the current search path.
675 This is always non-NULL. If it wasn't set already, then this will
676 return the default path.
678 =item $qemu = $h->get_qemu ();
680 Return the current qemu binary.
682 This is always non-NULL. If it wasn't set already, then this will
683 return the default qemu binary name.
685 =item $state = $h->get_state ();
687 This returns the current state as an opaque integer. This is
688 only useful for printing debug and internal error messages.
690 For more information on states, see L<guestfs(3)>.
692 =item $verbose = $h->get_verbose ();
694 This returns the verbose messages flag.
696 =item @paths = $h->glob_expand ($pattern);
698 This command searches for all the pathnames matching
699 C<pattern> according to the wildcard expansion rules
702 If no paths match, then this returns an empty list
703 (note: not an error).
705 It is just a wrapper around the C L<glob(3)> function
706 with flags C<GLOB_MARK|GLOB_BRACE>.
707 See that manual page for more details.
709 =item $h->grub_install ($root, $device);
711 This command installs GRUB (the Grand Unified Bootloader) on
712 C<device>, with the root directory being C<root>.
714 =item @lines = $h->head ($path);
716 This command returns up to the first 10 lines of a file as
719 Because of the message protocol, there is a transfer limit
720 of somewhere between 2MB and 4MB. To transfer large files you should use
723 =item @lines = $h->head_n ($nrlines, $path);
725 If the parameter C<nrlines> is a positive number, this returns the first
726 C<nrlines> lines of the file C<path>.
728 If the parameter C<nrlines> is a negative number, this returns lines
729 from the file C<path>, excluding the last C<nrlines> lines.
731 If the parameter C<nrlines> is zero, this returns an empty list.
733 Because of the message protocol, there is a transfer limit
734 of somewhere between 2MB and 4MB. To transfer large files you should use
737 =item $dump = $h->hexdump ($path);
739 This runs C<hexdump -C> on the given C<path>. The result is
740 the human-readable, canonical hex dump of the file.
742 Because of the message protocol, there is a transfer limit
743 of somewhere between 2MB and 4MB. To transfer large files you should use
746 =item $busy = $h->is_busy ();
748 This returns true iff this handle is busy processing a command
749 (in the C<BUSY> state).
751 For more information on states, see L<guestfs(3)>.
753 =item $config = $h->is_config ();
755 This returns true iff this handle is being configured
756 (in the C<CONFIG> state).
758 For more information on states, see L<guestfs(3)>.
760 =item $dirflag = $h->is_dir ($path);
762 This returns C<true> if and only if there is a directory
763 with the given C<path> name. Note that it returns false for
764 other objects like files.
766 See also C<$h-E<gt>stat>.
768 =item $fileflag = $h->is_file ($path);
770 This returns C<true> if and only if there is a file
771 with the given C<path> name. Note that it returns false for
772 other objects like directories.
774 See also C<$h-E<gt>stat>.
776 =item $launching = $h->is_launching ();
778 This returns true iff this handle is launching the subprocess
779 (in the C<LAUNCHING> state).
781 For more information on states, see L<guestfs(3)>.
783 =item $ready = $h->is_ready ();
785 This returns true iff this handle is ready to accept commands
786 (in the C<READY> state).
788 For more information on states, see L<guestfs(3)>.
790 =item $h->kill_subprocess ();
792 This kills the qemu subprocess. You should never need to call this.
796 Internally libguestfs is implemented by running a virtual machine
799 You should call this after configuring the handle
800 (eg. adding drives) but before performing any actions.
802 =item @devices = $h->list_devices ();
804 List all the block devices.
806 The full block device names are returned, eg. C</dev/sda>
808 =item @partitions = $h->list_partitions ();
810 List all the partitions detected on all block devices.
812 The full partition device names are returned, eg. C</dev/sda1>
814 This does not return logical volumes. For that you will need to
817 =item $listing = $h->ll ($directory);
819 List the files in C<directory> (relative to the root directory,
820 there is no cwd) in the format of 'ls -la'.
822 This command is mostly useful for interactive sessions. It
823 is I<not> intended that you try to parse the output string.
825 =item @listing = $h->ls ($directory);
827 List the files in C<directory> (relative to the root directory,
828 there is no cwd). The '.' and '..' entries are not returned, but
829 hidden files are shown.
831 This command is mostly useful for interactive sessions. Programs
832 should probably use C<$h-E<gt>readdir> instead.
834 =item %statbuf = $h->lstat ($path);
836 Returns file information for the given C<path>.
838 This is the same as C<$h-E<gt>stat> except that if C<path>
839 is a symbolic link, then the link is stat-ed, not the file it
842 This is the same as the C<lstat(2)> system call.
844 =item $h->lvcreate ($logvol, $volgroup, $mbytes);
846 This creates an LVM volume group called C<logvol>
847 on the volume group C<volgroup>, with C<size> megabytes.
849 =item $h->lvm_remove_all ();
851 This command removes all LVM logical volumes, volume groups
852 and physical volumes.
854 B<This command is dangerous. Without careful use you
855 can easily destroy all your data>.
857 =item $h->lvremove ($device);
859 Remove an LVM logical volume C<device>, where C<device> is
860 the path to the LV, such as C</dev/VG/LV>.
862 You can also remove all LVs in a volume group by specifying
863 the VG name, C</dev/VG>.
865 =item $h->lvresize ($device, $mbytes);
867 This resizes (expands or shrinks) an existing LVM logical
868 volume to C<mbytes>. When reducing, data in the reduced part
871 =item @logvols = $h->lvs ();
873 List all the logical volumes detected. This is the equivalent
874 of the L<lvs(8)> command.
876 This returns a list of the logical volume device names
877 (eg. C</dev/VolGroup00/LogVol00>).
879 See also C<$h-E<gt>lvs_full>.
881 =item @logvols = $h->lvs_full ();
883 List all the logical volumes detected. This is the equivalent
884 of the L<lvs(8)> command. The "full" version includes all fields.
886 =item $h->mkdir ($path);
888 Create a directory named C<path>.
890 =item $h->mkdir_p ($path);
892 Create a directory named C<path>, creating any parent directories
893 as necessary. This is like the C<mkdir -p> shell command.
895 =item $dir = $h->mkdtemp ($template);
897 This command creates a temporary directory. The
898 C<template> parameter should be a full pathname for the
899 temporary directory name with the final six characters being
902 For example: "/tmp/myprogXXXXXX" or "/Temp/myprogXXXXXX",
903 the second one being suitable for Windows filesystems.
905 The name of the temporary directory that was created
908 The temporary directory is created with mode 0700
909 and is owned by root.
911 The caller is responsible for deleting the temporary
912 directory and its contents after use.
914 See also: L<mkdtemp(3)>
916 =item $h->mkfs ($fstype, $device);
918 This creates a filesystem on C<device> (usually a partition
919 or LVM logical volume). The filesystem type is C<fstype>, for
922 =item $h->mount ($device, $mountpoint);
924 Mount a guest disk at a position in the filesystem. Block devices
925 are named C</dev/sda>, C</dev/sdb> and so on, as they were added to
926 the guest. If those block devices contain partitions, they will have
927 the usual names (eg. C</dev/sda1>). Also LVM C</dev/VG/LV>-style
930 The rules are the same as for L<mount(2)>: A filesystem must
931 first be mounted on C</> before others can be mounted. Other
932 filesystems can only be mounted on directories which already
935 The mounted filesystem is writable, if we have sufficient permissions
936 on the underlying device.
938 The filesystem options C<sync> and C<noatime> are set with this
939 call, in order to improve reliability.
941 =item $h->mount_options ($options, $device, $mountpoint);
943 This is the same as the C<$h-E<gt>mount> command, but it
944 allows you to set the mount options as for the
945 L<mount(8)> I<-o> flag.
947 =item $h->mount_ro ($device, $mountpoint);
949 This is the same as the C<$h-E<gt>mount> command, but it
950 mounts the filesystem with the read-only (I<-o ro>) flag.
952 =item $h->mount_vfs ($options, $vfstype, $device, $mountpoint);
954 This is the same as the C<$h-E<gt>mount> command, but it
955 allows you to set both the mount options and the vfstype
956 as for the L<mount(8)> I<-o> and I<-t> flags.
958 =item @devices = $h->mounts ();
960 This returns the list of currently mounted filesystems. It returns
961 the list of devices (eg. C</dev/sda1>, C</dev/VG/LV>).
963 Some internal mounts are not shown.
965 =item $h->mv ($src, $dest);
967 This moves a file from C<src> to C<dest> where C<dest> is
968 either a destination filename or destination directory.
970 =item $status = $h->ntfs_3g_probe ($rw, $device);
972 This command runs the L<ntfs-3g.probe(8)> command which probes
973 an NTFS C<device> for mountability. (Not all NTFS volumes can
974 be mounted read-write, and some cannot be mounted at all).
976 C<rw> is a boolean flag. Set it to true if you want to test
977 if the volume can be mounted read-write. Set it to false if
978 you want to test if the volume can be mounted read-only.
980 The return value is an integer which C<0> if the operation
981 would succeed, or some non-zero value documented in the
982 L<ntfs-3g.probe(8)> manual page.
984 =item $h->ping_daemon ();
986 This is a test probe into the guestfs daemon running inside
987 the qemu subprocess. Calling this function checks that the
988 daemon responds to the ping message, without affecting the daemon
989 or attached block device(s) in any other way.
991 =item $h->pvcreate ($device);
993 This creates an LVM physical volume on the named C<device>,
994 where C<device> should usually be a partition name such
997 =item $h->pvremove ($device);
999 This wipes a physical volume C<device> so that LVM will no longer
1002 The implementation uses the C<pvremove> command which refuses to
1003 wipe physical volumes that contain any volume groups, so you have
1004 to remove those first.
1006 =item $h->pvresize ($device);
1008 This resizes (expands or shrinks) an existing LVM physical
1009 volume to match the new size of the underlying device.
1011 =item @physvols = $h->pvs ();
1013 List all the physical volumes detected. This is the equivalent
1014 of the L<pvs(8)> command.
1016 This returns a list of just the device names that contain
1017 PVs (eg. C</dev/sda2>).
1019 See also C<$h-E<gt>pvs_full>.
1021 =item @physvols = $h->pvs_full ();
1023 List all the physical volumes detected. This is the equivalent
1024 of the L<pvs(8)> command. The "full" version includes all fields.
1026 =item @lines = $h->read_lines ($path);
1028 Return the contents of the file named C<path>.
1030 The file contents are returned as a list of lines. Trailing
1031 C<LF> and C<CRLF> character sequences are I<not> returned.
1033 Note that this function cannot correctly handle binary files
1034 (specifically, files containing C<\0> character which is treated
1035 as end of line). For those you need to use the C<$h-E<gt>read_file>
1036 function which has a more complex interface.
1038 =item $h->resize2fs ($device);
1040 This resizes an ext2 or ext3 filesystem to match the size of
1041 the underlying device.
1043 I<Note:> It is sometimes required that you run C<$h-E<gt>e2fsck_f>
1044 on the C<device> before calling this command. For unknown reasons
1045 C<resize2fs> sometimes gives an error about this and sometimes not.
1046 In any case, it is always safe to call C<$h-E<gt>e2fsck_f> before
1047 calling this function.
1049 =item $h->rm ($path);
1051 Remove the single file C<path>.
1053 =item $h->rm_rf ($path);
1055 Remove the file or directory C<path>, recursively removing the
1056 contents if its a directory. This is like the C<rm -rf> shell
1059 =item $h->rmdir ($path);
1061 Remove the single directory C<path>.
1063 =item $h->scrub_device ($device);
1065 This command writes patterns over C<device> to make data retrieval
1068 It is an interface to the L<scrub(1)> program. See that
1069 manual page for more details.
1071 B<This command is dangerous. Without careful use you
1072 can easily destroy all your data>.
1074 =item $h->scrub_file ($file);
1076 This command writes patterns over a file to make data retrieval
1079 The file is I<removed> after scrubbing.
1081 It is an interface to the L<scrub(1)> program. See that
1082 manual page for more details.
1084 =item $h->scrub_freespace ($dir);
1086 This command creates the directory C<dir> and then fills it
1087 with files until the filesystem is full, and scrubs the files
1088 as for C<$h-E<gt>scrub_file>, and deletes them.
1089 The intention is to scrub any free space on the partition
1092 It is an interface to the L<scrub(1)> program. See that
1093 manual page for more details.
1095 =item $h->set_append ($append);
1097 This function is used to add additional options to the
1098 guest kernel command line.
1100 The default is C<NULL> unless overridden by setting
1101 C<LIBGUESTFS_APPEND> environment variable.
1103 Setting C<append> to C<NULL> means I<no> additional options
1104 are passed (libguestfs always adds a few of its own).
1106 =item $h->set_autosync ($autosync);
1108 If C<autosync> is true, this enables autosync. Libguestfs will make a
1109 best effort attempt to run C<$h-E<gt>umount_all> followed by
1110 C<$h-E<gt>sync> when the handle is closed
1111 (also if the program exits without closing handles).
1113 This is disabled by default (except in guestfish where it is
1114 enabled by default).
1116 =item $h->set_busy ();
1118 This sets the state to C<BUSY>. This is only used when implementing
1119 actions using the low-level API.
1121 For more information on states, see L<guestfs(3)>.
1123 =item $h->set_e2label ($device, $label);
1125 This sets the ext2/3/4 filesystem label of the filesystem on
1126 C<device> to C<label>. Filesystem labels are limited to
1129 You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2label>
1130 to return the existing label on a filesystem.
1132 =item $h->set_e2uuid ($device, $uuid);
1134 This sets the ext2/3/4 filesystem UUID of the filesystem on
1135 C<device> to C<uuid>. The format of the UUID and alternatives
1136 such as C<clear>, C<random> and C<time> are described in the
1137 L<tune2fs(8)> manpage.
1139 You can use either C<$h-E<gt>tune2fs_l> or C<$h-E<gt>get_e2uuid>
1140 to return the existing UUID of a filesystem.
1142 =item $h->set_path ($path);
1144 Set the path that libguestfs searches for kernel and initrd.img.
1146 The default is C<$libdir/guestfs> unless overridden by setting
1147 C<LIBGUESTFS_PATH> environment variable.
1149 Setting C<path> to C<NULL> restores the default path.
1151 =item $h->set_qemu ($qemu);
1153 Set the qemu binary that we will use.
1155 The default is chosen when the library was compiled by the
1158 You can also override this by setting the C<LIBGUESTFS_QEMU>
1159 environment variable.
1161 Setting C<qemu> to C<NULL> restores the default qemu binary.
1163 =item $h->set_ready ();
1165 This sets the state to C<READY>. This is only used when implementing
1166 actions using the low-level API.
1168 For more information on states, see L<guestfs(3)>.
1170 =item $h->set_verbose ($verbose);
1172 If C<verbose> is true, this turns on verbose messages (to C<stderr>).
1174 Verbose messages are disabled unless the environment variable
1175 C<LIBGUESTFS_DEBUG> is defined and set to C<1>.
1177 =item $h->sfdisk ($device, $cyls, $heads, $sectors, \@lines);
1179 This is a direct interface to the L<sfdisk(8)> program for creating
1180 partitions on block devices.
1182 C<device> should be a block device, for example C</dev/sda>.
1184 C<cyls>, C<heads> and C<sectors> are the number of cylinders, heads
1185 and sectors on the device, which are passed directly to sfdisk as
1186 the I<-C>, I<-H> and I<-S> parameters. If you pass C<0> for any
1187 of these, then the corresponding parameter is omitted. Usually for
1188 'large' disks, you can just pass C<0> for these, but for small
1189 (floppy-sized) disks, sfdisk (or rather, the kernel) cannot work
1190 out the right geometry and you will need to tell it.
1192 C<lines> is a list of lines that we feed to C<sfdisk>. For more
1193 information refer to the L<sfdisk(8)> manpage.
1195 To create a single partition occupying the whole disk, you would
1196 pass C<lines> as a single element list, when the single element being
1197 the string C<,> (comma).
1199 See also: C<$h-E<gt>sfdisk_l>, C<$h-E<gt>sfdisk_N>
1201 B<This command is dangerous. Without careful use you
1202 can easily destroy all your data>.
1204 =item $h->sfdisk_N ($device, $partnum, $cyls, $heads, $sectors, $line);
1206 This runs L<sfdisk(8)> option to modify just the single
1207 partition C<n> (note: C<n> counts from 1).
1209 For other parameters, see C<$h-E<gt>sfdisk>. You should usually
1210 pass C<0> for the cyls/heads/sectors parameters.
1212 B<This command is dangerous. Without careful use you
1213 can easily destroy all your data>.
1215 =item $partitions = $h->sfdisk_disk_geometry ($device);
1217 This displays the disk geometry of C<device> read from the
1218 partition table. Especially in the case where the underlying
1219 block device has been resized, this can be different from the
1220 kernel's idea of the geometry (see C<$h-E<gt>sfdisk_kernel_geometry>).
1222 The result is in human-readable format, and not designed to
1225 =item $partitions = $h->sfdisk_kernel_geometry ($device);
1227 This displays the kernel's idea of the geometry of C<device>.
1229 The result is in human-readable format, and not designed to
1232 =item $partitions = $h->sfdisk_l ($device);
1234 This displays the partition table on C<device>, in the
1235 human-readable output of the L<sfdisk(8)> command. It is
1236 not intended to be parsed.
1238 =item $output = $h->sh ($command);
1240 This call runs a command from the guest filesystem via the
1243 This is like C<$h-E<gt>command>, but passes the command to:
1245 /bin/sh -c "command"
1247 Depending on the guest's shell, this usually results in
1248 wildcards being expanded, shell expressions being interpolated
1251 All the provisos about C<$h-E<gt>command> apply to this call.
1253 =item @lines = $h->sh_lines ($command);
1255 This is the same as C<$h-E<gt>sh>, but splits the result
1256 into a list of lines.
1258 See also: C<$h-E<gt>command_lines>
1260 =item $h->sleep ($secs);
1262 Sleep for C<secs> seconds.
1264 =item %statbuf = $h->stat ($path);
1266 Returns file information for the given C<path>.
1268 This is the same as the C<stat(2)> system call.
1270 =item %statbuf = $h->statvfs ($path);
1272 Returns file system statistics for any mounted file system.
1273 C<path> should be a file or directory in the mounted file system
1274 (typically it is the mount point itself, but it doesn't need to be).
1276 This is the same as the C<statvfs(2)> system call.
1278 =item @stringsout = $h->strings ($path);
1280 This runs the L<strings(1)> command on a file and returns
1281 the list of printable strings found.
1283 Because of the message protocol, there is a transfer limit
1284 of somewhere between 2MB and 4MB. To transfer large files you should use
1287 =item @stringsout = $h->strings_e ($encoding, $path);
1289 This is like the C<$h-E<gt>strings> command, but allows you to
1290 specify the encoding.
1292 See the L<strings(1)> manpage for the full list of encodings.
1294 Commonly useful encodings are C<l> (lower case L) which will
1295 show strings inside Windows/x86 files.
1297 The returned strings are transcoded to UTF-8.
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
1305 This syncs the disk, so that any writes are flushed through to the
1306 underlying disk image.
1308 You should always call this if you have modified a disk image, before
1311 =item @lines = $h->tail ($path);
1313 This command returns up to the last 10 lines of a file as
1316 Because of the message protocol, there is a transfer limit
1317 of somewhere between 2MB and 4MB. To transfer large files you should use
1320 =item @lines = $h->tail_n ($nrlines, $path);
1322 If the parameter C<nrlines> is a positive number, this returns the last
1323 C<nrlines> lines of the file C<path>.
1325 If the parameter C<nrlines> is a negative number, this returns lines
1326 from the file C<path>, starting with the C<-nrlines>th line.
1328 If the parameter C<nrlines> is zero, this returns an empty list.
1330 Because of the message protocol, there is a transfer limit
1331 of somewhere between 2MB and 4MB. To transfer large files you should use
1334 =item $h->tar_in ($tarfile, $directory);
1336 This command uploads and unpacks local file C<tarfile> (an
1337 I<uncompressed> tar file) into C<directory>.
1339 To upload a compressed tarball, use C<$h-E<gt>tgz_in>.
1341 =item $h->tar_out ($directory, $tarfile);
1343 This command packs the contents of C<directory> and downloads
1344 it to local file C<tarfile>.
1346 To download a compressed tarball, use C<$h-E<gt>tgz_out>.
1348 =item $h->tgz_in ($tarball, $directory);
1350 This command uploads and unpacks local file C<tarball> (a
1351 I<gzip compressed> tar file) into C<directory>.
1353 To upload an uncompressed tarball, use C<$h-E<gt>tar_in>.
1355 =item $h->tgz_out ($directory, $tarball);
1357 This command packs the contents of C<directory> and downloads
1358 it to local file C<tarball>.
1360 To download an uncompressed tarball, use C<$h-E<gt>tar_out>.
1362 =item $h->touch ($path);
1364 Touch acts like the L<touch(1)> command. It can be used to
1365 update the timestamps on a file, or, if the file does not exist,
1366 to create a new zero-length file.
1368 =item %superblock = $h->tune2fs_l ($device);
1370 This returns the contents of the ext2, ext3 or ext4 filesystem
1371 superblock on C<device>.
1373 It is the same as running C<tune2fs -l device>. See L<tune2fs(8)>
1374 manpage for more details. The list of fields returned isn't
1375 clearly defined, and depends on both the version of C<tune2fs>
1376 that libguestfs was built against, and the filesystem itself.
1378 =item $h->umount ($pathordevice);
1380 This unmounts the given filesystem. The filesystem may be
1381 specified either by its mountpoint (path) or the device which
1382 contains the filesystem.
1384 =item $h->umount_all ();
1386 This unmounts all mounted filesystems.
1388 Some internal mounts are not unmounted by this call.
1390 =item $h->upload ($filename, $remotefilename);
1392 Upload local file C<filename> to C<remotefilename> on the
1395 C<filename> can also be a named pipe.
1397 See also C<$h-E<gt>download>.
1399 =item $h->vg_activate ($activate, \@volgroups);
1401 This command activates or (if C<activate> is false) deactivates
1402 all logical volumes in the listed volume groups C<volgroups>.
1403 If activated, then they are made known to the
1404 kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
1405 then those devices disappear.
1407 This command is the same as running C<vgchange -a y|n volgroups...>
1409 Note that if C<volgroups> is an empty list then B<all> volume groups
1410 are activated or deactivated.
1412 =item $h->vg_activate_all ($activate);
1414 This command activates or (if C<activate> is false) deactivates
1415 all logical volumes in all volume groups.
1416 If activated, then they are made known to the
1417 kernel, ie. they appear as C</dev/mapper> devices. If deactivated,
1418 then those devices disappear.
1420 This command is the same as running C<vgchange -a y|n>
1422 =item $h->vgcreate ($volgroup, \@physvols);
1424 This creates an LVM volume group called C<volgroup>
1425 from the non-empty list of physical volumes C<physvols>.
1427 =item $h->vgremove ($vgname);
1429 Remove an LVM volume group C<vgname>, (for example C<VG>).
1431 This also forcibly removes all logical volumes in the volume
1434 =item @volgroups = $h->vgs ();
1436 List all the volumes groups detected. This is the equivalent
1437 of the L<vgs(8)> command.
1439 This returns a list of just the volume group names that were
1440 detected (eg. C<VolGroup00>).
1442 See also C<$h-E<gt>vgs_full>.
1444 =item @volgroups = $h->vgs_full ();
1446 List all the volumes groups detected. This is the equivalent
1447 of the L<vgs(8)> command. The "full" version includes all fields.
1449 =item $h->wait_ready ();
1451 Internally libguestfs is implemented by running a virtual machine
1454 You should call this after C<$h-E<gt>launch> to wait for the launch
1457 =item $chars = $h->wc_c ($path);
1459 This command counts the characters in a file, using the
1460 C<wc -c> external command.
1462 =item $lines = $h->wc_l ($path);
1464 This command counts the lines in a file, using the
1465 C<wc -l> external command.
1467 =item $words = $h->wc_w ($path);
1469 This command counts the words in a file, using the
1470 C<wc -w> external command.
1472 =item $h->write_file ($path, $content, $size);
1474 This call creates a file called C<path>. The contents of the
1475 file is the string C<content> (which can contain any 8 bit data),
1476 with length C<size>.
1478 As a special case, if C<size> is C<0>
1479 then the length is calculated using C<strlen> (so in this case
1480 the content cannot contain embedded ASCII NULs).
1482 I<NB.> Owing to a bug, writing content containing ASCII NUL
1483 characters does I<not> work, even if the length is specified.
1484 We hope to resolve this bug in a future version. In the meantime
1485 use C<$h-E<gt>upload>.
1487 Because of the message protocol, there is a transfer limit
1488 of somewhere between 2MB and 4MB. To transfer large files you should use
1491 =item $h->zero ($device);
1493 This command writes zeroes over the first few blocks of C<device>.
1495 How many blocks are zeroed isn't specified (but it's I<not> enough
1496 to securely wipe the device). It should be sufficient to remove
1497 any partition tables, filesystem superblocks and so on.
1499 See also: C<$h-E<gt>scrub_device>.
1501 =item $h->zerofree ($device);
1503 This runs the I<zerofree> program on C<device>. This program
1504 claims to zero unused inodes and disk blocks on an ext2/3
1505 filesystem, thus making it possible to compress the filesystem
1508 You should B<not> run this program if the filesystem is
1511 It is possible that using this program can damage the filesystem
1512 or data on the filesystem.
1522 Copyright (C) 2009 Red Hat Inc.
1526 Please see the file COPYING.LIB for the full license.
1530 L<guestfs(3)>, L<guestfish(1)>.