guestfs_download (g, filename, "/dev/stdout");
-and you can write tar output to a pipe C<fd> by doing:
+and you can write tar output to a file descriptor C<fd> by doing:
char devfd[64];
snprintf (devfd, sizeof devfd, "/dev/fd/%d", fd);
=item B<Java>
Full documentation is contained in the Javadoc which is distributed
-with libguestfs.
+with libguestfs. For examples, see L<guestfs-java(3)>.
=item B<OCaml>
=item Autosync / forgetting to sync.
+I<Update:> Autosync is enabled by default for all API users starting
+from libguestfs 1.5.24. This section only applies to older versions.
+
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:
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
to free the handle and release all resources used.
For information on using multiple handles and threads, see the section
-L</MULTIPLE HANDLES AND MULTIPLE THREADS> below.
+L</MULTIPLE HANDLES AND MULTIPLE THREADS> above.
=head2 guestfs_create
C<guestfs_set_subprocess_quit_callback>,
C<guestfs_set_launch_done_callback>, C<guestfs_set_close_callback> and
C<guestfs_set_progress_callback> are no longer documented in this
-manual page.
+manual page. Because of the ABI guarantee, the old functions continue
+to work.
Handles generate events when certain things happen, such as log
messages being generated, progress messages during long-running
syslog (priority, "event 0x%lx: %s", event, buf);
}
+=head1 CANCELLING LONG TRANSFERS
+
+Some operations can be cancelled by the caller while they are in
+progress. Currently only operations that involve uploading or
+downloading data can be cancelled (technically: operations that have
+C<FileIn> or C<FileOut> parameters in the generator).
+
+=head2 guestfs_user_cancel
+
+ void guestfs_user_cancel (guestfs_h *g);
+
+C<guestfs_user_cancel> cancels the current upload or download
+operation.
+
+Unlike most other libguestfs calls, this function is signal safe and
+thread safe. You can call it from a signal handler or from another
+thread, without needing to do any locking.
+
+The transfer that was in progress (if there is one) will stop shortly
+afterwards, and will return an error. The errno (see
+L</guestfs_last_errno>) is set to C<EINTR>, so you can test for this
+to find out if the operation was cancelled or failed because of
+another error.
+
+No cleanup is performed: for example, if a file was being uploaded
+then after cancellation there may be a partially uploaded file. It is
+the caller's responsibility to clean up if necessary.
+
+There are two common places that you might call C<guestfs_user_cancel>.
+
+In an interactive text-based program, you might call it from a
+C<SIGINT> signal handler so that pressing C<^C> cancels the current
+operation. (You also need to call L</guestfs_set_pgroup> so that
+child processes don't receive the C<^C> signal).
+
+In a graphical program, when the main thread is displaying a progress
+bar with a cancel button, wire up the cancel button to call this
+function.
+
=head1 PRIVATE DATA AREA
You can attach named pieces of private data to the libguestfs handle,
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.
+same key 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.
+You can use any C<key> you want, but your key should I<not> start with
+an underscore character. Keys beginning with an underscore character
+are reserved for internal libguestfs purposes (eg. for implementing
+language bindings). It is recommended that you prefix the key with
+some unique string to avoid collisions with other users.
To retrieve the pointer, use:
The L<virt-cat(1)>, L<virt-filesystems(1)> and L<virt-ls(1)> commands
and documentation.
+=item C<caution>
+
+Safety and liveness tests of components that libguestfs depends upon
+(not of libguestfs itself). Mainly this is for qemu and the kernel.
+
=item C<contrib>
Outside contributions, experimental parts.
L<virt-df(1)> command and documentation.
+=item C<edit>
+
+L<virt-edit(1)> command and documentation.
+
=item C<examples>
C API example code.
=back
+=head2 MAKING A STABLE RELEASE
+
+When we make a stable release, there are several steps documented
+here. See L</LIBGUESTFS VERSION NUMBERS> for general information
+about the stable branch policy.
+
+=over 4
+
+=item *
+
+Check C<make && make check> works on at least Fedora, Debian and
+Ubuntu.
+
+=item *
+
+Finalize RELEASE-NOTES.
+
+=item *
+
+Update ROADMAP.
+
+=item *
+
+Run C<src/api-support/update-from-tarballs.sh>.
+
+=item *
+
+Push and pull from Transifex.
+
+Run:
+
+ tx push -s
+
+to push the latest POT files to Transifex. Then run:
+
+ ./tx-pull.sh
+
+which is a wrapper to pull the latest translated C<*.po> files.
+
+=item *
+
+Create new stable and development directories under
+L<http://libguestfs.org/download>.
+
+=item *
+
+Create the branch in git:
+
+ git tag -a 1.XX.0 -m "Version 1.XX.0 (stable)"
+ git tag -a 1.YY.0 -m "Version 1.YY.0 (development)"
+ git branch stable-1.XX
+ git push origin tag 1.XX.0 1.YY.0 stable-1.XX
+
+=back
+
=head1 LIMITS
=head2 PROTOCOL LIMITS
1,152,921,504,606,846,976 bytes) using sparse files backed by an XFS
host filesystem.
+Although libguestfs probably does not impose any limit, the underlying
+host storage will. If you store disk images on a host ext4
+filesystem, then the maximum size will be limited by the maximum ext4
+file size (currently 16 TB). If you store disk images as host logical
+volumes then you are limited by the maximum size of an LV.
+
+For the hugest disk image files, we recommend using XFS on the host
+for storage.
+
=head2 MAXIMUM SIZE OF A PARTITION
The MBR (ie. classic MS-DOS) partitioning scheme uses 32 bit sector
=head1 SEE ALSO
L<guestfs-examples(3)>,
+L<guestfs-java(3)>,
L<guestfs-ocaml(3)>,
+L<guestfs-perl(3)>,
L<guestfs-python(3)>,
L<guestfs-ruby(3)>,
L<guestfish(1)>,
git.annexia.org / libguestfs.git / blobdiff