#include <guestfs.h>
- guestfs_h *handle = guestfs_create ();
- guestfs_add_drive (handle, "guest.img");
- guestfs_launch (handle);
- guestfs_mount (handle, "/dev/sda1", "/");
- guestfs_touch (handle, "/hello");
- guestfs_sync (handle);
- guestfs_close (handle);
+ guestfs_h *g = guestfs_create ();
+ guestfs_add_drive (g, "guest.img");
+ guestfs_launch (g);
+ guestfs_mount (g, "/dev/sda1", "/");
+ guestfs_touch (g, "/hello");
+ guestfs_umount (g, "/");
+ guestfs_sync (g);
+ guestfs_close (g);
+
+ cc prog.c -o prog -lguestfs
+or:
+ cc prog.c -o prog `pkg-config libguestfs --cflags --libs`
=head1 DESCRIPTION
Libguestfs provides ways to enumerate guest storage (eg. partitions,
LVs, what filesystem is in each LV, etc.). It can also run commands
-in the context of the guest. Also you can access filesystems over FTP.
+in the context of the guest. Also you can access filesystems over
+FUSE.
Libguestfs is a library that can be linked with C and C++ management
programs (or management programs written in OCaml, Perl, Python, Ruby,
-Java, Haskell or C#). You can also use it from shell scripts or the
+Java, PHP, Haskell or C#). You can also use it from shell scripts or the
command line.
You don't need to be root to use libguestfs, although obviously you do
This section provides a gentler overview of the libguestfs API. We
also try to group API calls together, where that may not be obvious
-from reading about the individual calls below.
+from reading about the individual calls in the main section of this
+manual.
=head2 HANDLES
Before you can use libguestfs calls, you have to create a handle.
Then you must add at least one disk image to the handle, followed by
launching the handle, then performing whatever operations you want,
-and finally closing the handle. So the general structure of all
-libguestfs-using programs looks like this:
+and finally closing the handle. By convention we use the single
+letter C<g> for the name of the handle variable, although of course
+you can use any name you want.
- guestfs_h *handle = guestfs_create ();
+The general structure of all libguestfs-using programs looks like
+this:
+
+ guestfs_h *g = guestfs_create ();
/* Call guestfs_add_drive additional times if there are
* multiple disk images.
*/
- guestfs_add_drive (handle, "guest.img");
+ guestfs_add_drive (g, "guest.img");
/* Most manipulation calls won't work until you've launched
- * the handle. You have to do this _after_ adding drives
+ * the handle 'g'. You have to do this _after_ adding drives
* and _before_ other commands.
*/
- guestfs_launch (handle);
+ guestfs_launch (g);
/* Now you can examine what partitions, LVs etc are available.
*/
- char **partitions = guestfs_list_partitions (handle);
- char **logvols = guestfs_lvs (handle);
+ char **partitions = guestfs_list_partitions (g);
+ char **logvols = guestfs_lvs (g);
/* To access a filesystem in the image, you must mount it.
*/
- guestfs_mount (handle, "/dev/sda1", "/");
+ guestfs_mount (g, "/dev/sda1", "/");
/* Now you can perform filesystem actions on the guest
* disk image.
*/
- guestfs_touch (handle, "/hello");
+ guestfs_touch (g, "/hello");
/* You only need to call guestfs_sync if you have made
- * changes to the guest image.
+ * changes to the guest image. (But if you've made changes
+ * then you *must* sync). See also: guestfs_umount and
+ * guestfs_umount_all calls.
*/
- guestfs_sync (handle);
+ guestfs_sync (g);
- /* Close the handle. */
- guestfs_close (handle);
+ /* Close the handle 'g'. */
+ guestfs_close (g);
The code above doesn't include any error checking. In real code you
should check return values carefully for errors. In general all
you have created through L<posix_fallocate(3)>. Libguestfs lets you
do useful things to all of these.
-You can add a disk read-only using C<guestfs_add_drive_ro>, in which
+The call you should use in modern code for adding drives is
+L</guestfs_add_drive_opts>. To add a disk image, allowing writes, and
+specifying that the format is raw, do:
+
+ guestfs_add_drive_opts (g, filename,
+ GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
+ -1);
+
+You can add a disk read-only using:
+
+ guestfs_add_drive_opts (g, filename,
+ GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
+ GUESTFS_ADD_DRIVE_OPTS_READONLY, 1,
+ -1);
+
+or by calling the older function L</guestfs_add_drive_ro>. In either
case libguestfs won't modify the file.
Be extremely cautious if the disk image is in use, eg. if it is being
C</dev/sda> (for the first one you added), C</dev/sdb> (for the second
one you added), etc.
-Once C<guestfs_launch> has been called you cannot add any more images.
-You can call C<guestfs_list_devices> to get a list of the device
+Once L</guestfs_launch> has been called you cannot add any more images.
+You can call L</guestfs_list_devices> to get a list of the device
names, in the order that you added them. See also L</BLOCK DEVICE
NAMING> below.
Before you can read or write files, create directories and so on in a
disk image that contains filesystems, you have to mount those
-filesystems using C<guestfs_mount>. If you already know that a disk
+filesystems using L</guestfs_mount>. If you already know that a disk
image contains (for example) one partition with a filesystem on that
partition, then you can mount it directly:
- guestfs_mount (handle, "/dev/sda1", "/");
+ guestfs_mount (g, "/dev/sda1", "/");
where C</dev/sda1> means literally the first partition (C<1>) of the
first disk image that we added (C</dev/sda>). If the disk contains
If you are given a disk image and you don't know what it contains then
you have to find out. Libguestfs can do that too: use
-C<guestfs_list_partitions> and C<guestfs_lvs> to list possible
+L</guestfs_list_partitions> and L</guestfs_lvs> to list possible
partitions and LVs, and either try mounting each to see what is
-mountable, or else examine them with C<guestfs_file>. But you might
-find it easier to look at higher level programs built on top of
-libguestfs, in particular L<virt-inspector(1)>.
+mountable, or else examine them with L</guestfs_vfs_type> or
+L</guestfs_file>. Libguestfs also has a set of APIs for inspection of
+disk images (see L</INSPECTION> below). But you might find it easier
+to look at higher level programs built on top of libguestfs, in
+particular L<virt-inspector(1)>.
-To mount a disk image read-only, use C<guestfs_mount_ro>. There are
+To mount a disk image read-only, use L</guestfs_mount_ro>. There are
several other variations of the C<guestfs_mount_*> call.
=head2 FILESYSTEM ACCESS AND MODIFICATION
can find listed in detail below in this man page, and we don't even
pretend to cover them all in this overview.
-Specify filenames as full paths including the mount point.
+Specify filenames as full paths, starting with C<"/"> and including
+the mount point.
For example, if you mounted a filesystem at C<"/"> and you want to
read the file called C<"etc/passwd"> then you could do:
- char *data = guestfs_cat (handle, "/etc/passwd");
+ char *data = guestfs_cat (g, "/etc/passwd");
This would return C<data> as a newly allocated buffer containing the
full content of that file (with some conditions: see also
As another example, to create a top-level directory on that filesystem
called C<"var"> you would do:
- guestfs_mkdir (handle, "/var");
+ guestfs_mkdir (g, "/var");
To create a symlink you could do:
- guestfs_ln_s (handle, "/etc/init.d/portmap",
+ guestfs_ln_s (g, "/etc/init.d/portmap",
"/etc/rc3.d/S30portmap");
-Libguestfs will reject attempts to use relative paths. There is no
-concept of a current working directory. Libguestfs can return errors
-in many situations: for example if the filesystem isn't writable, or
-if a file or directory that you requested doesn't exist. If you are
-using the C API (documented here) you have to check for those error
-conditions after each call. (Other language bindings turn these
-errors into exceptions).
+Libguestfs will reject attempts to use relative paths and there is no
+concept of a current working directory.
+
+Libguestfs can return errors in many situations: for example if the
+filesystem isn't writable, or if a file or directory that you
+requested doesn't exist. If you are using the C API (documented here)
+you have to check for those error conditions after each call. (Other
+language bindings turn these errors into exceptions).
File writes are affected by the per-handle umask, set by calling
-C<guestfs_umask> and defaulting to 022.
+L</guestfs_umask> and defaulting to 022. See L</UMASK>.
=head2 PARTITIONING
tables on disk images.
In the common case where you want to create a single partition
-covering the whole disk, you should use the C<guestfs_part_disk>
+covering the whole disk, you should use the L</guestfs_part_disk>
call:
const char *parttype = "mbr";
Obviously this effectively wipes anything that was on that disk image
before.
-In general MBR partitions are both unnecessarily complicated and
-depend on archaic details, namely the Cylinder-Head-Sector (CHS)
-geometry of the disk. C<guestfs_sfdiskM> can be used to
-create more complex arrangements where the relative sizes are
-expressed in megabytes instead of cylinders, which is a small win.
-C<guestfs_sfdiskM> will choose the nearest cylinder to approximate the
-requested size. There's a lot of crazy stuff to do with IDE and
-virtio disks having different, incompatible CHS geometries, that you
-probably don't want to know about.
-
-My advice: make a single partition to cover the whole disk, then use
-LVM on top.
-
=head2 LVM2
Libguestfs provides access to a large part of the LVM2 API, such as
-C<guestfs_lvcreate> and C<guestfs_vgremove>. It won't make much sense
+L</guestfs_lvcreate> and L</guestfs_vgremove>. It won't make much sense
unless you familiarize yourself with the concepts of physical volumes,
volume groups and logical volumes.
=head2 DOWNLOADING
-Use C<guestfs_cat> to download small, text only files. This call
+Use L</guestfs_cat> to download small, text only files. This call
is limited to files which are less than 2 MB and which cannot contain
any ASCII NUL (C<\0>) characters. However it has a very simple
to use API.
-C<guestfs_read_file> can be used to read files which contain
+L</guestfs_read_file> can be used to read files which contain
arbitrary 8 bit data, since it returns a (pointer, size) pair.
However it is still limited to "small" files, less than 2 MB.
-C<guestfs_download> can be used to download any file, with no
+L</guestfs_download> can be used to download any file, with no
limits on content or size (even files larger than 4 GB).
-To download multiple files, see C<guestfs_tar_out> and
-C<guestfs_tgz_out>.
+To download multiple files, see L</guestfs_tar_out> and
+L</guestfs_tgz_out>.
=head2 UPLOADING
It's often the case that you want to write a file or files to the disk
image.
-For small, single files, use C<guestfs_write_file>. This call
-currently contains a bug which limits the call to plain text files
-(not containing ASCII NUL characters).
+To write a small file with fixed content, use L</guestfs_write>. To
+create a file of all zeroes, use L</guestfs_truncate_size> (sparse) or
+L</guestfs_fallocate64> (with all disk blocks allocated). There are a
+variety of other functions for creating test files, for example
+L</guestfs_fill> and L</guestfs_fill_pattern>.
-To upload a single file, use C<guestfs_upload>. This call has no
+To upload a single file, use L</guestfs_upload>. This call has no
limits on file content or size (even files larger than 4 GB).
-To upload multiple files, see C<guestfs_tar_in> and C<guestfs_tgz_in>.
+To upload multiple files, see L</guestfs_tar_in> and L</guestfs_tgz_in>.
However the fastest way to upload I<large numbers of arbitrary files>
is to turn them into a squashfs or CD ISO (see L<mksquashfs(8)> and
-L<mkisofs(8)>), then attach this using C<guestfs_add_drive_ro>. If
+L<mkisofs(8)>), then attach this using L</guestfs_add_drive_ro>. If
you add the drive in a predictable way (eg. adding it last after all
other drives) then you can get the device name from
-C<guestfs_list_devices> and mount it directly using
-C<guestfs_mount_ro>. Note that squashfs images are sometimes
+L</guestfs_list_devices> and mount it directly using
+L</guestfs_mount_ro>. Note that squashfs images are sometimes
non-portable between kernel versions, and they don't support labels or
UUIDs. If you want to pre-build an image or you need to mount it
using a label or UUID, use an ISO image instead.
guestfs_dd (g, "/dev/VG/Original", "/dev/VG/Copy");
The destination (C</dev/VG/Copy>) must be at least as large as the
-source (C</dev/VG/Original>).
+source (C</dev/VG/Original>). To copy less than the whole
+source device, use L</guestfs_copy_size>.
=item B<file on the host> to B<file or device>
=head2 LISTING FILES
-C<guestfs_ll> is just designed for humans to read (mainly when using
+L</guestfs_ll> is just designed for humans to read (mainly when using
the L<guestfish(1)>-equivalent command C<ll>).
-C<guestfs_ls> is a quick way to get a list of files in a directory
+L</guestfs_ls> is a quick way to get a list of files in a directory
from programs, as a flat list of strings.
-C<guestfs_readdir> is a programmatic way to get a list of files in a
+L</guestfs_readdir> is a programmatic way to get a list of files in a
directory, plus additional information about each one. It is more
equivalent to using the L<readdir(3)> call on a local filesystem.
-C<guestfs_find> can be used to recursively list files.
+L</guestfs_find> and L</guestfs_find0> can be used to recursively list
+files.
=head2 RUNNING COMMANDS
-Although libguestfs is a primarily an API for manipulating files
+Although libguestfs is primarily an API for manipulating files
inside guest images, we also provide some limited facilities for
running commands inside guests.
=item *
+The network may not be available unless you enable it
+(see L</guestfs_set_network>).
+
+=item *
+
Only supports Linux guests (not Windows, BSD, etc).
=item *
=back
-The two main API calls to run commands are C<guestfs_command> and
-C<guestfs_sh> (there are also variations).
+The two main API calls to run commands are L</guestfs_command> and
+L</guestfs_sh> (there are also variations).
-The difference is that C<guestfs_sh> runs commands using the shell, so
+The difference is that L</guestfs_sh> runs commands using the shell, so
any shell globs, redirections, etc will work.
=head2 CONFIGURATION FILES
documentation on the L<http://augeas.net/> website.
If you don't want to use Augeas (you fool!) then try calling
-C<guestfs_read_lines> to get the file as a list of lines which
+L</guestfs_read_lines> to get the file as a list of lines which
you can iterate over.
=head2 SELINUX
for example by running the external command
C<restorecon pathname>.
+=head2 UMASK
+
+Certain calls are affected by the current file mode creation mask (the
+"umask"). In particular ones which create files or directories, such
+as L</guestfs_touch>, L</guestfs_mknod> or L</guestfs_mkdir>. This
+affects either the default mode that the file is created with or
+modifies the mode that you supply.
+
+The default umask is C<022>, so files are created with modes such as
+C<0644> and directories with C<0755>.
+
+There are two ways to avoid being affected by umask. Either set umask
+to 0 (call C<guestfs_umask (g, 0)> early after launching). Or call
+L</guestfs_chmod> after creating each file or directory.
+
+For more information about umask, see L<umask(2)>.
+
+=head2 ENCRYPTED DISKS
+
+Libguestfs allows you to access Linux guests which have been
+encrypted using whole disk encryption that conforms to the
+Linux Unified Key Setup (LUKS) standard. This includes
+nearly all whole disk encryption systems used by modern
+Linux guests.
+
+Use L</guestfs_vfs_type> to identify LUKS-encrypted block
+devices (it returns the string C<crypto_LUKS>).
+
+Then open these devices by calling L</guestfs_luks_open>.
+Obviously you will require the passphrase!
+
+Opening a LUKS device creates a new device mapper device
+called C</dev/mapper/mapname> (where C<mapname> is the
+string you supply to L</guestfs_luks_open>).
+Reads and writes to this mapper device are decrypted from and
+encrypted to the underlying block device respectively.
+
+LVM volume groups on the device can be made visible by calling
+L</guestfs_vgscan> followed by L</guestfs_vg_activate_all>.
+The logical volume(s) can now be mounted in the usual way.
+
+Use the reverse process to close a LUKS device. Unmount
+any logical volumes on it, deactivate the volume groups
+by caling C<guestfs_vg_activate (g, 0, ["/dev/VG"])>.
+Then close the mapper device by calling
+L</guestfs_luks_close> on the C</dev/mapper/mapname>
+device (I<not> the underlying encrypted block device).
+
+=head2 INSPECTION
+
+Libguestfs has APIs for inspecting an unknown disk image to find out
+if it contains operating systems. (These APIs used to be in a
+separate Perl-only library called L<Sys::Guestfs::Lib(3)> but since
+version 1.5.3 the most frequently used part of this library has been
+rewritten in C and moved into the core code).
+
+Add all disks belonging to the unknown virtual machine and call
+L</guestfs_launch> in the usual way.
+
+Then call L</guestfs_inspect_os>. This function uses other libguestfs
+calls and certain heuristics, and returns a list of operating systems
+that were found. An empty list means none were found. A single
+element is the root filesystem of the operating system. For dual- or
+multi-boot guests, multiple roots can be returned, each one
+corresponding to a separate operating system. (Multi-boot virtual
+machines are extremely rare in the world of virtualization, but since
+this scenario can happen, we have built libguestfs to deal with it.)
+
+For each root, you can then call various C<guestfs_inspect_get_*>
+functions to get additional details about that operating system. For
+example, call L</guestfs_inspect_get_type> to return the string
+C<windows> or C<linux> for Windows and Linux-based operating systems
+respectively.
+
+Un*x-like and Linux-based operating systems usually consist of several
+filesystems which are mounted at boot time (for example, a separate
+boot partition mounted on C</boot>). The inspection rules are able to
+detect how filesystems correspond to mount points. Call
+C<guestfs_inspect_get_mountpoints> to get this mapping. It might
+return a hash table like this example:
+
+ /boot => /dev/sda1
+ / => /dev/vg_guest/lv_root
+ /usr => /dev/vg_guest/lv_usr
+
+The caller can then make calls to L</guestfs_mount_options> to
+mount the filesystems as suggested.
+
+Be careful to mount filesystems in the right order (eg. C</> before
+C</usr>). Sorting the keys of the hash by length, shortest first,
+should work.
+
+Inspection currently only works for some common operating systems.
+Contributors are welcome to send patches for other operating systems
+that we currently cannot detect.
+
+Encrypted disks must be opened before inspection. See
+L</ENCRYPTED DISKS> for more details. The L</guestfs_inspect_os>
+function just ignores any encrypted devices.
+
+A note on the implementation: The call L</guestfs_inspect_os> performs
+inspection and caches the results in the guest handle. Subsequent
+calls to C<guestfs_inspect_get_*> return this cached information, but
+I<do not> re-read the disks. If you change the content of the guest
+disks, you can redo inspection by calling L</guestfs_inspect_os>
+again.
+
=head2 SPECIAL CONSIDERATIONS FOR WINDOWS GUESTS
Libguestfs can mount NTFS partitions. It does this using the
Drive letter mappings are outside the scope of libguestfs. You have
to use libguestfs to read the appropriate Windows Registry and
configuration files, to determine yourself how drives are mapped (see
-also L<virt-inspector(1)>).
+also L<hivex(3)> and L<virt-inspector(1)>).
Replacing backslash characters with forward slash characters is also
outside the scope of libguestfs, but something that you can easily do.
Where we can help is in resolving the case insensitivity of paths.
-For this, call C<guestfs_case_sensitive_path>.
+For this, call L</guestfs_case_sensitive_path>.
Libguestfs also provides some help for decoding Windows Registry
-"hive" files, through the library C<libhivex> which is part of
-libguestfs. You have to locate and download the hive file(s)
-yourself, and then pass them to C<libhivex> functions. See also the
-programs L<hivexml(1)>, L<hivexget(1)> and L<virt-win-reg(1)> for more
-help on this issue.
+"hive" files, through the library C<hivex> which is part of the
+libguestfs project although ships as a separate tarball. You have to
+locate and download the hive file(s) yourself, and then pass them to
+C<hivex> functions. See also the programs L<hivexml(1)>,
+L<hivexsh(1)>, L<hivexregedit(1)> and L<virt-win-reg(1)> for more help
+on this issue.
=head2 USING LIBGUESTFS WITH OTHER PROGRAMMING LANGUAGES
mention here that the same API is also available in other languages.
The API is broadly identical in all supported languages. This means
-that the C call C<guestfs_mount(handle,path)> is
-C<$handle-E<gt>mount($path)> in Perl, C<handle.mount(path)> in Python,
-and C<Guestfs.mount handle path> in OCaml. In other words, a
+that the C call C<guestfs_mount(g,path)> is
+C<$g-E<gt>mount($path)> in Perl, C<g.mount(path)> in Python,
+and C<Guestfs.mount g path> in OCaml. In other words, a
straightforward, predictable isomorphism between each language.
Error messages are automatically transformed
=item B<C++>
You can use the I<guestfs.h> header file from C++ programs. The C++
-API is identical to the C API. C++ classes and exceptions are
-not implemented.
+API is identical to the C API. C++ classes and exceptions are not
+used.
=item B<C#>
=item B<Haskell>
-This is the only language binding that working but incomplete. Only
-calls which return simple integers have been bound in Haskell, and we
-are looking for help to complete this binding.
+This is the only language binding that is working but incomplete.
+Only calls which return simple integers have been bound in Haskell,
+and we are looking for help to complete this binding.
=item B<Java>
For documentation see L<Sys::Guestfs(3)>.
+=item B<PHP>
+
+For documentation see C<README-PHP> supplied with libguestfs
+sources or in the php-libguestfs package for your distribution.
+
+The PHP binding only works correctly on 64 bit machines.
+
=item B<Python>
For documentation do:
=back
+=head2 LIBGUESTFS GOTCHAS
+
+L<http://en.wikipedia.org/wiki/Gotcha_(programming)>: "A feature of a
+system [...] that works in the way it is documented but is
+counterintuitive and almost invites mistakes."
+
+Since we developed libguestfs and the associated tools, there are
+several things we would have designed differently, but are now stuck
+with for backwards compatibility or other reasons. If there is ever a
+libguestfs 2.0 release, you can expect these to change. Beware of
+them.
+
+=over 4
+
+=item Autosync / forgetting to sync.
+
+When modifying a filesystem from C or another language, you B<must>
+unmount all filesystems and call L</guestfs_sync> explicitly before
+you close the libguestfs handle. You can also call:
+
+ guestfs_set_autosync (g, 1);
+
+to have the unmount/sync done automatically for you when the handle 'g'
+is closed. (This feature is called "autosync", L</guestfs_set_autosync>
+q.v.)
+
+If you forget to do this, then it is entirely possible that your
+changes won't be written out, or will be partially written, or (very
+rarely) that you'll get disk corruption.
+
+Note that in L<guestfish(3)> autosync is the default. So quick and
+dirty guestfish scripts that forget to sync will work just fine, which
+can make this very puzzling if you are trying to debug a problem.
+
+Update: Autosync is enabled by default for all API users starting from
+libguestfs 1.5.24.
+
+=item Mount option C<-o sync> should not be the default.
+
+If you use L</guestfs_mount>, then C<-o sync,noatime> are added
+implicitly. However C<-o sync> does not add any reliability benefit,
+but does have a very large performance impact.
+
+The work around is to use L</guestfs_mount_options> and set the mount
+options that you actually want to use.
+
+=item Read-only should be the default.
+
+In L<guestfish(3)>, I<--ro> should be the default, and you should
+have to specify I<--rw> if you want to make changes to the image.
+
+This would reduce the potential to corrupt live VM images.
+
+Note that many filesystems change the disk when you just mount and
+unmount, even if you didn't perform any writes. You need to use
+L</guestfs_add_drive_ro> to guarantee that the disk is not changed.
+
+=item guestfish command line is hard to use.
+
+C<guestfish disk.img> doesn't do what people expect (open C<disk.img>
+for examination). It tries to run a guestfish command C<disk.img>
+which doesn't exist, so it fails. In earlier versions of guestfish
+the error message was also unintuitive, but we have corrected this
+since. Like the Bourne shell, we should have used C<guestfish -c
+command> to run commands.
+
+=item guestfish megabyte modifiers don't work right on all commands
+
+In recent guestfish you can use C<1M> to mean 1 megabyte (and
+similarly for other modifiers). What guestfish actually does is to
+multiply the number part by the modifier part and pass the result to
+the C API. However this doesn't work for a few APIs which aren't
+expecting bytes, but are already expecting some other unit
+(eg. megabytes).
+
+The most common is L</guestfs_lvcreate>. The guestfish command:
+
+ lvcreate LV VG 100M
+
+does not do what you might expect. Instead because
+L</guestfs_lvcreate> is already expecting megabytes, this tries to
+create a 100 I<terabyte> (100 megabytes * megabytes) logical volume.
+The error message you get from this is also a little obscure.
+
+This could be fixed in the generator by specially marking parameters
+and return values which take bytes or other units.
+
+=item Library should return errno with error messages.
+
+It would be a nice-to-have to be able to get the original value of
+'errno' from inside the appliance along error paths (where set).
+Currently L<guestmount(1)> goes through hoops to try to reverse the
+error message string into an errno, see the function error() in
+fuse/guestmount.c.
+
+In libguestfs 1.5.4, the protocol was changed so that the
+Linux errno is sent back from the daemon.
+
+=item Ambiguity between devices and paths
+
+There is a subtle ambiguity in the API between a device name
+(eg. C</dev/sdb2>) and a similar pathname. A file might just happen
+to be called C<sdb2> in the directory C</dev> (consider some non-Unix
+VM image).
+
+In the current API we usually resolve this ambiguity by having two
+separate calls, for example L</guestfs_checksum> and
+L</guestfs_checksum_device>. Some API calls are ambiguous and
+(incorrectly) resolve the problem by detecting if the path supplied
+begins with C</dev/>.
+
+To avoid both the ambiguity and the need to duplicate some calls, we
+could make paths/devices into structured names. One way to do this
+would be to use a notation like grub (C<hd(0,0)>), although nobody
+really likes this aspect of grub. Another way would be to use a
+structured type, equivalent to this OCaml type:
+
+ type path = Path of string | Device of int | Partition of int * int
+
+which would allow you to pass arguments like:
+
+ Path "/foo/bar"
+ Device 1 (* /dev/sdb, or perhaps /dev/sda *)
+ Partition (1, 2) (* /dev/sdb2 (or is it /dev/sda2 or /dev/sdb3?) *)
+ Path "/dev/sdb2" (* not a device *)
+
+As you can see there are still problems to resolve even with this
+representation. Also consider how it might work in guestfish.
+
+=back
+
+=head2 PROTOCOL LIMITS
+
+Internally libguestfs uses a message-based protocol to pass API calls
+and their responses to and from a small "appliance" (see L</INTERNALS>
+for plenty more detail about this). The maximum message size used by
+the protocol is slightly less than 4 MB. For some API calls you may
+need to be aware of this limit. The API calls which may be affected
+are individually documented, with a link back to this section of the
+documentation.
+
+A simple call such as L</guestfs_cat> returns its result (the file
+data) in a simple string. Because this string is at some point
+internally encoded as a message, the maximum size that it can return
+is slightly under 4 MB. If the requested file is larger than this
+then you will get an error.
+
+In order to transfer large files into and out of the guest filesystem,
+you need to use particular calls that support this. The sections
+L</UPLOADING> and L</DOWNLOADING> document how to do this.
+
+You might also consider mounting the disk image using our FUSE
+filesystem support (L<guestmount(1)>).
+
+=head2 KEYS AND PASSPHRASES
+
+Certain libguestfs calls take a parameter that contains sensitive key
+material, passed in as a C string.
+
+In the future we would hope to change the libguestfs implementation so
+that keys are L<mlock(2)>-ed into physical RAM, and thus can never end
+up in swap. However this is I<not> done at the moment, because of the
+complexity of such an implementation.
+
+Therefore you should be aware that any key parameter you pass to
+libguestfs might end up being written out to the swap partition. If
+this is a concern, scrub the swap partition or don't use libguestfs on
+encrypted devices.
+
=head1 CONNECTION MANAGEMENT
=head2 guestfs_h *
C<guestfs_h> is the opaque type representing a connection handle.
-Create a handle by calling C<guestfs_create>. Call C<guestfs_close>
+Create a handle by calling L</guestfs_create>. Call L</guestfs_close>
to free the handle and release all resources used.
For information on using multiple handles and threads, see the section
Create a connection handle.
-You have to call C<guestfs_add_drive> on the handle at least once.
+You have to call L</guestfs_add_drive_opts> (or one of the equivalent
+calls) on the handle at least once.
This function returns a non-NULL pointer to a handle on success or
NULL on error.
-After configuring the handle, you have to call C<guestfs_launch>.
+After configuring the handle, you have to call L</guestfs_launch>.
You may also want to configure error handling for the handle. See
L</ERROR HANDLING> section below.
=head2 guestfs_close
- void guestfs_close (guestfs_h *handle);
+ void guestfs_close (guestfs_h *g);
This closes the connection handle and frees up all resources used.
The convention in all functions that return C<int> is that they return
C<-1> to indicate an error. You can get additional information on
-errors by calling C<guestfs_last_error> and/or by setting up an error
-handler with C<guestfs_set_error_handler>.
+errors by calling L</guestfs_last_error> and/or by setting up an error
+handler with L</guestfs_set_error_handler>.
The default error handler prints the information string to C<stderr>.
Out of memory errors are handled differently. The default action is
to call L<abort(3)>. If this is undesirable, then you can set a
-handler using C<guestfs_set_out_of_memory_handler>.
+handler using L</guestfs_set_out_of_memory_handler>.
=head2 guestfs_last_error
- const char *guestfs_last_error (guestfs_h *handle);
+ const char *guestfs_last_error (guestfs_h *g);
-This returns the last error message that happened on C<handle>. If
+This returns the last error message that happened on C<g>. If
there has not been an error since the handle was created, then this
returns C<NULL>.
The lifetime of the returned string is until the next error occurs, or
-C<guestfs_close> is called.
+L</guestfs_close> is called.
The error string is not localized (ie. is always in English), because
this makes searching for error messages in search engines give the
=head2 guestfs_set_error_handler
- typedef void (*guestfs_error_handler_cb) (guestfs_h *handle,
- void *data,
+ typedef void (*guestfs_error_handler_cb) (guestfs_h *g,
+ void *opaque,
const char *msg);
- void guestfs_set_error_handler (guestfs_h *handle,
+ void guestfs_set_error_handler (guestfs_h *g,
guestfs_error_handler_cb cb,
- void *data);
+ void *opaque);
The callback C<cb> will be called if there is an error. The
parameters passed to the callback are an opaque data pointer and the
=head2 guestfs_get_error_handler
- guestfs_error_handler_cb guestfs_get_error_handler (guestfs_h *handle,
- void **data_rtn);
+ guestfs_error_handler_cb guestfs_get_error_handler (guestfs_h *g,
+ void **opaque_rtn);
Returns the current error handler callback.
=head2 guestfs_set_out_of_memory_handler
typedef void (*guestfs_abort_cb) (void);
- int guestfs_set_out_of_memory_handler (guestfs_h *handle,
+ int guestfs_set_out_of_memory_handler (guestfs_h *g,
guestfs_abort_cb);
The callback C<cb> will be called if there is an out of memory
=head2 guestfs_get_out_of_memory_handler
- guestfs_abort_fn guestfs_get_out_of_memory_handler (guestfs_h *handle);
+ guestfs_abort_fn guestfs_get_out_of_memory_handler (guestfs_h *g);
This returns the current out of memory handler.
By default it looks for these in the directory C<$libdir/guestfs>
(eg. C</usr/local/lib/guestfs> or C</usr/lib64/guestfs>).
-Use C<guestfs_set_path> or set the environment variable
-C<LIBGUESTFS_PATH> to change the directories that libguestfs will
+Use L</guestfs_set_path> or set the environment variable
+L</LIBGUESTFS_PATH> to change the directories that libguestfs will
search in. The value is a colon-separated list of paths. The current
directory is I<not> searched unless the path contains an empty element
or C<.>. For example C<LIBGUESTFS_PATH=:/usr/lib/guestfs> would
high-level actions as outlined in this section. Although we will
deprecate some actions, for example if they get replaced by newer
calls, we will keep the old actions forever. This allows you the
-developer to program in confidence against libguestfs.
+developer to program in confidence against the libguestfs API.
@ACTIONS@
@AVAILABILITY@
+=head2 GUESTFISH supported COMMAND
+
+In L<guestfish(3)> there is a handy interactive command
+C<supported> which prints out the available groups and
+whether they are supported by this build of libguestfs.
+Note however that you have to do C<run> first.
+
=head2 SINGLE CALLS AT COMPILE TIME
-If you need to test whether a single libguestfs function is
-available at compile time, we recommend using build tools
-such as autoconf or cmake. For example in autotools you could
-use:
+Since version 1.5.8, C<E<lt>guestfs.hE<gt>> defines symbols
+for each C API function, such as:
+
+ #define LIBGUESTFS_HAVE_DD 1
+
+if L</guestfs_dd> is available.
+
+Before version 1.5.8, if you needed to test whether a single
+libguestfs function is available at compile time, we recommended using
+build tools such as autoconf or cmake. For example in autotools you
+could use:
AC_CHECK_LIB([guestfs],[guestfs_create])
AC_CHECK_FUNCS([guestfs_dd])
at run time, as in this example program (note that you still
need the compile time check as well):
- #include <config.h>
-
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
main ()
{
- #ifdef HAVE_GUESTFS_DD
+ #ifdef LIBGUESTFS_HAVE_DD
void *dl;
int has_function;
dl = dlopen (NULL, RTLD_LAZY);
if (!dl) {
fprintf (stderr, "dlopen: %s\n", dlerror ());
- exit (1);
+ exit (EXIT_FAILURE);
}
has_function = dlsym (dl, "guestfs_dd") != NULL;
dlclose (dl);
Requires: libguestfs >= 1.0.80
+=head1 CALLS WITH OPTIONAL ARGUMENTS
+
+A recent feature of the API is the introduction of calls which take
+optional arguments. In C these are declared 3 ways. The main way is
+as a call which takes variable arguments (ie. C<...>), as in this
+example:
+
+ int guestfs_add_drive_opts (guestfs_h *g, const char *filename, ...);
+
+Call this with a list of optional arguments, terminated by C<-1>.
+So to call with no optional arguments specified:
+
+ guestfs_add_drive_opts (g, filename, -1);
+
+With a single optional argument:
+
+ guestfs_add_drive_opts (g, filename,
+ GUESTFS_ADD_DRIVE_OPTS_FORMAT, "qcow2",
+ -1);
+
+With two:
+
+ guestfs_add_drive_opts (g, filename,
+ GUESTFS_ADD_DRIVE_OPTS_FORMAT, "qcow2",
+ GUESTFS_ADD_DRIVE_OPTS_READONLY, 1,
+ -1);
+
+and so forth. Don't forget the terminating C<-1> otherwise
+Bad Things will happen!
+
+=head2 USING va_list FOR OPTIONAL ARGUMENTS
+
+The second variant has the same name with the suffix C<_va>, which
+works the same way but takes a C<va_list>. See the C manual for
+details. For the example function, this is declared:
+
+ int guestfs_add_drive_opts_va (guestfs_h *g, const char *filename,
+ va_list args);
+
+=head2 CONSTRUCTING OPTIONAL ARGUMENTS
+
+The third variant is useful where you need to construct these
+calls. You pass in a structure where you fill in the optional
+fields. The structure has a bitmask as the first element which
+you must set to indicate which fields you have filled in. For
+our example function the structure and call are declared:
+
+ struct guestfs_add_drive_opts_argv {
+ uint64_t bitmask;
+ int readonly;
+ const char *format;
+ /* ... */
+ };
+ int guestfs_add_drive_opts_argv (guestfs_h *g, const char *filename,
+ const struct guestfs_add_drive_opts_argv *optargs);
+
+You could call it like this:
+
+ struct guestfs_add_drive_opts_argv optargs = {
+ .bitmask = GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK |
+ GUESTFS_ADD_DRIVE_OPTS_FORMAT_BITMASK,
+ .readonly = 1,
+ .format = "qcow2"
+ };
+
+ guestfs_add_drive_opts_argv (g, filename, &optargs);
+
+Notes:
+
+=over 4
+
+=item *
+
+The C<_BITMASK> suffix on each option name when specifying the
+bitmask.
+
+=item *
+
+You do not need to fill in all fields of the structure.
+
+=item *
+
+There must be a one-to-one correspondence between fields of the
+structure that are filled in, and bits set in the bitmask.
+
+=back
+
+=head2 OPTIONAL ARGUMENTS IN OTHER LANGUAGES
+
+In other languages, optional arguments are expressed in the
+way that is natural for that language. We refer you to the
+language-specific documentation for more details on that.
+
+For guestfish, see L<guestfish(1)/OPTIONAL ARGUMENTS>.
+
=begin html
<!-- old anchor for the next section -->
Inside the appliance is a Linux kernel and a complete stack of
userspace tools (such as LVM and ext2 programs) and a small
-controlling daemon called C<guestfsd>. The library talks to
-C<guestfsd> using remote procedure calls (RPC). There is a mostly
+controlling daemon called L</guestfsd>. The library talks to
+L</guestfsd> using remote procedure calls (RPC). There is a mostly
one-to-one correspondence between libguestfs API calls and RPC calls
to the daemon. Lastly the disk image(s) are attached to the qemu
process which translates device access by the appliance's Linux kernel
booting up), (3) alternating between READY and BUSY as commands are
issued to, and carried out by, the child process.
-The guest may be killed by C<guestfs_kill_subprocess>, or may die
+The guest may be killed by L</guestfs_kill_subprocess>, or may die
asynchronously at any time (eg. due to some internal error), and that
causes the state to transition back to CONFIG.
-Configuration commands for qemu such as C<guestfs_add_drive> can only
+Configuration commands for qemu such as L</guestfs_add_drive> can only
be issued when in the CONFIG state.
-The high-level API offers two calls that go from CONFIG through
-LAUNCHING to READY. C<guestfs_launch> blocks until the child process
-is READY to accept commands (or until some failure or timeout).
-C<guestfs_launch> internally moves the state from CONFIG to LAUNCHING
+The API offers one call that goes from CONFIG through LAUNCHING to
+READY. L</guestfs_launch> blocks until the child process is READY to
+accept commands (or until some failure or timeout).
+L</guestfs_launch> internally moves the state from CONFIG to LAUNCHING
while it is running.
-High-level API actions such as C<guestfs_mount> can only be issued
-when in the READY state. These high-level API calls block waiting for
-the command to be carried out (ie. the state to transition to BUSY and
-then back to READY). But using the low-level event API, you get
-non-blocking versions. (But you can still only carry out one
-operation per handle at a time - that is a limitation of the
-communications protocol we use).
+API actions such as L</guestfs_mount> can only be issued when in the
+READY state. These API calls block waiting for the command to be
+carried out (ie. the state to transition to BUSY and then back to
+READY). There are no non-blocking versions, and no way to issue more
+than one command per handle at the same time.
Finally, the child process sends asynchronous messages back to the
-main program, such as kernel log messages. Mostly these are ignored
-by the high-level API, but using the low-level event API you can
-register to receive these messages.
+main program, such as kernel log messages. You can register a
+callback to receive these messages.
=head2 SETTING CALLBACKS TO HANDLE EVENTS
typedef void (*guestfs_log_message_cb) (guestfs_h *g, void *opaque,
char *buf, int len);
- void guestfs_set_log_message_callback (guestfs_h *handle,
+ void guestfs_set_log_message_callback (guestfs_h *g,
guestfs_log_message_cb cb,
void *opaque);
=head2 guestfs_set_subprocess_quit_callback
typedef void (*guestfs_subprocess_quit_cb) (guestfs_h *g, void *opaque);
- void guestfs_set_subprocess_quit_callback (guestfs_h *handle,
+ void guestfs_set_subprocess_quit_callback (guestfs_h *g,
guestfs_subprocess_quit_cb cb,
void *opaque);
The callback function C<cb> will be called when the child process
quits, either asynchronously or if killed by
-C<guestfs_kill_subprocess>. (This corresponds to a transition from
+L</guestfs_kill_subprocess>. (This corresponds to a transition from
any state to the CONFIG state).
=head2 guestfs_set_launch_done_callback
typedef void (*guestfs_launch_done_cb) (guestfs_h *g, void *opaque);
- void guestfs_set_launch_done_callback (guestfs_h *handle,
- guestfs_ready_cb cb,
+ void guestfs_set_launch_done_callback (guestfs_h *g,
+ guestfs_launch_done_cb cb,
void *opaque);
The callback function C<cb> will be called when the child process
becomes ready first time after it has been launched. (This
corresponds to a transition from LAUNCHING to the READY state).
+=head2 guestfs_set_close_callback
+
+ typedef void (*guestfs_close_cb) (guestfs_h *g, void *opaque);
+ void guestfs_set_close_callback (guestfs_h *g,
+ guestfs_close_cb cb,
+ void *opaque);
+
+The callback function C<cb> will be called while the handle
+is being closed (synchronously from L</guestfs_close>).
+
+Note that libguestfs installs an L<atexit(3)> handler to try to
+clean up handles that are open when the program exits. This
+means that this callback might be called indirectly from
+L<exit(3)>, which can cause unexpected problems in higher-level
+languages (eg. if your HLL interpreter has already been cleaned
+up by the time this is called, and if your callback then jumps
+into some HLL function).
+
+=head2 guestfs_set_progress_callback
+
+ typedef void (*guestfs_progress_cb) (guestfs_h *g, void *opaque,
+ int proc_nr, int serial,
+ uint64_t position, uint64_t total);
+ void guestfs_set_progress_callback (guestfs_h *g,
+ guestfs_progress_cb cb,
+ void *opaque);
+
+Some long-running operations can generate progress messages. If
+this callback is registered, then it will be called each time a
+progress message is generated (usually two seconds after the
+operation started, and three times per second thereafter until
+it completes, although the frequency may change in future versions).
+
+The callback receives two numbers: C<position> and C<total>.
+The units of C<total> are not defined, although for some
+operations C<total> may relate in some way to the amount of
+data to be transferred (eg. in bytes or megabytes), and
+C<position> may be the portion which has been transferred.
+
+The only defined and stable parts of the API are:
+
+=over 4
+
+=item *
+
+The callback can display to the user some type of progress bar or
+indicator which shows the ratio of C<position>:C<total>.
+
+=item *
+
+0 E<lt>= C<position> E<lt>= C<total>
+
+=item *
+
+If any progress notification is sent during a call, then a final
+progress notification is always sent when C<position> = C<total>.
+
+This is to simplify caller code, so callers can easily set the
+progress indicator to "100%" at the end of the operation, without
+requiring special code to detect this case.
+
+=back
+
+The callback also receives the procedure number and serial number of
+the call. These are only useful for debugging protocol issues, and
+the callback can normally ignore them. The callback may want to
+print these numbers in error messages or debugging messages.
+
+=head1 PRIVATE DATA AREA
+
+You can attach named pieces of private data to the libguestfs handle,
+and fetch them by name for the lifetime of the handle. This is called
+the private data area and is only available from the C API.
+
+To attach a named piece of data, use the following call:
+
+ void guestfs_set_private (guestfs_h *g, const char *key, void *data);
+
+C<key> is the name to associate with this data, and C<data> is an
+arbitrary pointer (which can be C<NULL>). Any previous item with the
+same name is overwritten.
+
+You can use any C<key> you want, but names beginning with an
+underscore character are reserved for internal libguestfs purposes
+(for implementing language bindings). It is recommended to prefix the
+name with some unique string to avoid collisions with other users.
+
+To retrieve the pointer, use:
+
+ void *guestfs_get_private (guestfs_h *g, const char *key);
+
+This function returns C<NULL> if either no data is found associated
+with C<key>, or if the user previously set the C<key>'s C<data>
+pointer to C<NULL>.
+
+Libguestfs does not try to look at or interpret the C<data> pointer in
+any way. As far as libguestfs is concerned, it need not be a valid
+pointer at all. In particular, libguestfs does I<not> try to free the
+data when the handle is closed. If the data must be freed, then the
+caller must either free it before calling L</guestfs_close> or must
+set up a close callback to do it (see L</guestfs_set_close_callback>,
+and note that only one callback can be registered for a handle).
+
+The private data area is implemented using a hash table, and should be
+reasonably efficient for moderate numbers of keys.
+
=head1 BLOCK DEVICE NAMING
In the kernel there is now quite a profusion of schemata for naming
C</dev/hda2> transparently.
Note that this I<only> applies to parameters. The
-C<guestfs_list_devices>, C<guestfs_list_partitions> and similar calls
+L</guestfs_list_devices>, L</guestfs_list_partitions> and similar calls
return the true names of the devices and partitions as known to the
appliance.
Usually this translation is transparent. However in some (very rare)
cases you may need to know the exact algorithm. Such cases include
-where you use C<guestfs_config> to add a mixture of virtio and IDE
+where you use L</guestfs_config> to add a mixture of virtio and IDE
devices to the qemu-based appliance, so have a mixture of C</dev/sd*>
and C</dev/vd*> devices.
The algorithm is applied only to I<parameters> which are known to be
either device or partition names. Return values from functions such
-as C<guestfs_list_devices> are never changed.
+as L</guestfs_list_devices> are never changed.
=over 4
=item *
-Use C<guestfs_list_devices> or C<guestfs_list_partitions> to list
+Use L</guestfs_list_devices> or L</guestfs_list_partitions> to list
actual device names, and then use those names directly.
Since those device names exist by definition, they will never be
=head3 INITIAL MESSAGE
-Because the underlying channel (QEmu -net channel) doesn't have any
-sort of connection control, when the daemon launches it sends an
-initial word (C<GUESTFS_LAUNCH_FLAG>) which indicates that the guest
-and daemon is alive. This is what C<guestfs_launch> waits for.
+When the daemon launches it sends an initial word
+(C<GUESTFS_LAUNCH_FLAG>) which indicates that the guest and daemon is
+alive. This is what L</guestfs_launch> waits for.
+
+=head3 PROGRESS NOTIFICATION MESSAGES
+
+The daemon may send progress notification messages at any time. These
+are distinguished by the normal length word being replaced by
+C<GUESTFS_PROGRESS_FLAG>, followed by a fixed size progress message.
+
+The library turns them into progress callbacks (see
+C<guestfs_set_progress_callback>) if there is a callback registered,
+or discards them if not.
+
+The daemon self-limits the frequency of progress messages it sends
+(see C<daemon/proto.c:notify_progress>). Not all calls generate
+progress messages.
=head1 MULTIPLE HANDLES AND MULTIPLE THREADS
exclusively from one thread, or provide your own mutex so that two
threads cannot issue calls on the same handle at the same time.
+See the graphical program guestfs-browser for one possible
+architecture for multithreaded programs using libvirt and libguestfs.
+
=head1 QEMU WRAPPERS
If you want to compile your own qemu, run qemu from a non-standard
Note that libguestfs also calls qemu with the -help and -version
options in order to determine features.
+=head1 LIBGUESTFS VERSION NUMBERS
+
+Since April 2010, libguestfs has started to make separate development
+and stable releases, along with corresponding branches in our git
+repository. These separate releases can be identified by version
+number:
+
+ even numbers for stable: 1.2.x, 1.4.x, ...
+ .-------- odd numbers for development: 1.3.x, 1.5.x, ...
+ |
+ v
+ 1 . 3 . 5
+ ^ ^
+ | |
+ | `-------- sub-version
+ |
+ `------ always '1' because we don't change the ABI
+
+Thus "1.3.5" is the 5th update to the development branch "1.3".
+
+As time passes we cherry pick fixes from the development branch and
+backport those into the stable branch, the effect being that the
+stable branch should get more stable and less buggy over time. So the
+stable releases are ideal for people who don't need new features but
+would just like the software to work.
+
+Our criteria for backporting changes are:
+
+=over 4
+
+=item *
+
+Documentation changes which don't affect any code are
+backported unless the documentation refers to a future feature
+which is not in stable.
+
+=item *
+
+Bug fixes which are not controversial, fix obvious problems, and
+have been well tested are backported.
+
+=item *
+
+Simple rearrangements of code which shouldn't affect how it works get
+backported. This is so that the code in the two branches doesn't get
+too far out of step, allowing us to backport future fixes more easily.
+
+=item *
+
+We I<don't> backport new features, new APIs, new tools etc, except in
+one exceptional case: the new feature is required in order to
+implement an important bug fix.
+
+=back
+
+A new stable branch starts when we think the new features in
+development are substantial and compelling enough over the current
+stable branch to warrant it. When that happens we create new stable
+and development versions 1.N.0 and 1.(N+1).0 [N is even]. The new
+dot-oh release won't necessarily be so stable at this point, but by
+backporting fixes from development, that branch will stabilize over
+time.
+
=head1 ENVIRONMENT VARIABLES
=over 4
=item LIBGUESTFS_DEBUG
Set C<LIBGUESTFS_DEBUG=1> to enable verbose messages. This
-has the same effect as calling C<guestfs_set_verbose (handle, 1)>.
+has the same effect as calling C<guestfs_set_verbose (g, 1)>.
=item LIBGUESTFS_MEMSIZE
=item LIBGUESTFS_TRACE
Set C<LIBGUESTFS_TRACE=1> to enable command traces. This
-has the same effect as calling C<guestfs_set_trace (handle, 1)>.
+has the same effect as calling C<guestfs_set_trace (g, 1)>.
=item TMPDIR
Location of temporary directory, defaults to C</tmp>.
-If libguestfs was compiled to use the supermin appliance then each
-handle will require rather a large amount of space in this directory
-for short periods of time (~ 80 MB). You can use C<$TMPDIR> to
+If libguestfs was compiled to use the supermin appliance then the
+real appliance is cached in this directory, shared between all
+handles belonging to the same EUID. You can use C<$TMPDIR> to
configure another directory to use in case C</tmp> is not large
enough.
=head1 SEE ALSO
L<guestfish(1)>,
+L<guestmount(1)>,
+L<virt-cat(1)>,
+L<virt-df(1)>,
+L<virt-edit(1)>,
+L<virt-inspector(1)>,
+L<virt-list-filesystems(1)>,
+L<virt-list-partitions(1)>,
+L<virt-ls(1)>,
+L<virt-make-fs(1)>,
+L<virt-rescue(1)>,
+L<virt-tar(1)>,
+L<virt-win-reg(1)>,
L<qemu(1)>,
L<febootstrap(1)>,
+L<hivex(3)>,
L<http://libguestfs.org/>.
Tools with a similar purpose:
=head1 COPYRIGHT
-Copyright (C) 2009 Red Hat Inc.
+Copyright (C) 2009-2010 Red Hat Inc.
L<http://libguestfs.org/>
This library is free software; you can redistribute it and/or
git.annexia.org / libguestfs.git / blobdiff