This adds -Dnss-resolve= and -Dnss-mymachines= meson options.
By using this option, e.g., resolved can be built without nss-resolve.
When no nss modules are built, then test-nss is neither built.
Also, This changes the option name -Dmyhostname= to -Dnss-myhostname=
for consistency to other nss related options.
Closes#9596.
Usecase is to allow changing the final kill from SIGKILL to SIGQUIT which
should create a core dump useful for debugging why the service didn't stop
with the SIGTERM
User units were in the middle, which is just confusing. Let's discuss
all system units first, and all user units second.
I'm using "System manager units" and "user manager units" instead of the more
obvious "system units" and "user units", because there are also units like
"user@.service".
The original manpage says "Implies BBBAccounting" many times but actually that accounting is not implied by the respective resource control in v239 with the unified cgroup hierarchy. This commit removes those false explanations.
The current CLI does not support a way to clear these lists, since without any
additional arguments, the command will list the current values.
Introduce a new way to clear the lists by passing a single '' argument to these
subcommands.
Update the man page to document this.
Tested:
$ build/resolvectl domain eth1
Link 3 (eth1): ~.
$ build/resolvectl domain eth1 ''
$ build/resolvectl domain eth1
Link 3 (eth1):
$ build/resolvectl domain eth1 '~.' '~example.com'
$ build/resolvectl domain eth1
Link 3 (eth1): ~. ~example.com
$ build/resolvectl domain eth1 ''
$ build/resolvectl domain eth1
Link 3 (eth1):
$ build/resolvectl domain eth1 '~.'
$ build/resolvectl domain eth1
Link 3 (eth1): ~.
And similar for "dns" and "nta".
Back in 2012 the project was renamed, see the release notes for v 0.105
[https://cgit.freedesktop.org/polkit/tree/NEWS#n754]. Let's update our
documentation and comments to do the same. Referring to PolicyKit is confusing
to users because at the time the polkit api changed too, and we support the new
version. I updated NEWS too, since all the references to PolicyKit there were
added after the rename.
"PolicyKit" is unchanged in various URLs and method call names.
The kernel added support for a new cgroup memory controller knob memory.min in
bf8d5d52ffe8 ("memcg: introduce memory.min") which was merged during v4.18
merge window.
Add MemoryMin to support memory.min.
Use <literallayout> to keep each reference on a separate line. With all the
pages jumbled together into a paragraph, it is quite hard to find anything in
that list.
Also add the missing pages to the list. And remove the nonexistent ones — not
much point in advertisting pages that haven't been written yet.
This is useful if someone wants to recreate the original syslog datagram. We
already include timestamp information as _SOURCE_REALTIME_TIMESTAMP=, and in
normal use that timestamp, converted back to the form used by syslog
(Mth dd HH:MM:SS) would usually give the value. But there are various
circumstances where this might not be true. Most obviously, if the datagram is
sent a bit later after being prepared, the time is rounded to the nearest
second, and it might be off. This is especially bad around New Year when the
syslog timestamp wraps around. Then the same timezone and locale need to be
used to recreate the original timestamp. In the end doing this reliably is
complicated, and it seems much easier to just unconditionally include the
original timestamp.
If the original timestamp cannot be located, we store the full log line.
This way, it should be always possible to recreate the original input.
Example:
MESSAGE=x
SYSLOG_TIMESTAMP=Sep 15 15:07:58
SYSLOG_RAW
^]^@^@^@^@^@^@^@<13>Sep 15 15:07:58 HOST: x^@y
_PID=3318
_SOURCE_REALTIME_TIMESTAMP=1530743976393553
Fixes#2398.
One mention of --user was missing the surrounding <option> tag, making
the table look inconsistent (though the inconsistency is less obvious
after the reordering in 709f4c472c, since the four specifiers mentioning
the --user option are no longer immediately adjacent).
nspawn as it is now is a generally useful tool, hence let's drop the
comments about it being useful for debug and so on only.
The new wording just makes the first sentence of the main page also the
summary.
Similar semantics applies to {System,Runtime}MaxUse= as to
{System,Runtime}MaxFiles=, i.e. active files aren't vacuumed and the limit
is not thus strictly honored.
Let's fully document where the list of entries come from, including unified
images and such.
Let's add a "Files" section (replacing the "Configuration" section), and
let's move it after they keybinding section (why? because keybinds are
primary UI material, while configuration is one level more complex than
that).
Also, reword lot's of stuff to make it more precise.
Fixes: #5127
This is an additional synchronization point normally not needed. Hence,
let's make it passive, i.e. pull it in from the unit which wants to be
ordered before the update service rather than by the update service
itself.
systemd offline-updates allows dropping multiple system update units
to be added to system-update.target.wants.
As documented in systemd.offline-updates(7) only 1 of these units
should actually be active (based on the /system-update symlink) and
when that unit is done it should reboot the system.
In some cases it is desirable to run a unit whenever booting in
offline-updates mode indepedent of which update unit is going to
handle the update. One example of this is integration with bootloader
code which checks if the previous boot was succesful.
Since the active unit will reboot the system when it is done, there
is no guarantee that adding such a unit to system-update.target.wants
will get it executed always.
This commit adds a system-update-pre.target which can be used for
units which should always run when booting in offline-updates mode.
Currently we employ mostly system call blacklisting for our system
services. Let's add a new system call filter group @system-service that
helps turning this around into a whitelist by default.
The new group is very similar to nspawn's default filter list, but in
some ways more restricted (as sethostname() and suchlike shouldn't be
available to most system services just like that) and in others more
relaxed (for example @keyring is blocked in nspawn since it's not
properly virtualized yet in the kernel, but is fine for regular system
services).
Docbook styles required those to be present, even though the templates that we
use did not show those names anywhere. But something changed semi-recently (I
would suspect docbook templates, but there was only a minor version bump in
recent years, and the changelog does not suggest anything related), and builds
now work without those entries. Let's drop this dead weight.
Tested with F26-F29, debian unstable.
$ perl -i -0pe 's/\s*<authorgroup>.*<.authorgroup>//gms' man/*xml
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
To make debugging easier, this patches allows one to change the log target and
do reload/reexec without modifying configuration permanently, which makes
debugging easier.
Indeed if one changed the log target at runtime (via the bus or via signals),
the change was lost on the next reload/reexecution.
In order to restore back the default value (set via system.conf, environment
variables or any other means ), the empty string in the "LogTarget" property is
now supported as well as sending SIGTRMIN+26 signal.
To make debugging easier, this patches allows one to change the log level and
do reload/reexec without modifying configuration permanently, which makes
debugging easier.
Indeed if one changed the log max level at runtime (via the bus or via
signals), the change was lost on the next daemon reload/reexecution.
In order to restore the original value back (set via system.conf, environment
variables or any other means), the empty string in the "LogLevel" property is
now supported as well as sending SIGRTMIN+23 signal.
Since bb28e68477 parsing failures of
certain unit file settings will result in load failures of units. This
introduces a new load state "bad-setting" that is entered in precisely
this case.
With this addition error messages on bad settings should be a lot more
explicit, as we don't have to show some generic "errno" error in that
case, but can explicitly say that a bad setting is at fault.
Internally this unit load state is entered as soon as any configuration
loader call returns ENOEXEC. Hence: config parser calls should return
ENOEXEC now for such essential unit file settings. Turns out, they
generally already do.
Fixes: #9107
These states should never be visible to the outside, as they are used
only internally while loading unit. Hence let's drop them from the
documentation.
This adds a function sd_bus_slot_set_destroy_callback() to set a function
which can free userdata or perform other cleanups.
sd_bus_slot_get_destory_callback() queries the callback, and is included
for completeness.
Without something like this, for floating asynchronous callbacks, which might
be called or not, depending on the sequence of events, it's hard to perform
resource cleanup. The alternative would be to always perform the cleanup from
the caller too, but that requires more coordination and keeping of some shared
state. It's nicer to keep the cleanup contained between the callback and the
function that requests the callback.
The only difference is that functions are not individually listed by name,
but that seems completely pointless, since all functions that are documented
are always exported, so the generic text tells the user all she or he needs
to know.
Fedora 28 is out already, let's advertise it. While at it, drop "container"
from "f28container" — it's a subdirectory under /var/lib/machines, it's pretty
obvious that's it a container.
To make the switch easier in the future, define the number as an entity.
This "netdevsim" as implied by the name is a tool for network developers and is a simulator.
This simulated networking device is used for testing various networking APIs and at this time
is particularly focused on testing hardware offloading related interfaces.
'systemctl disable --runtime' would disable a unit, but only if it was enabled
with '--runtime', and silently do nothing if the unit was enabled persistently.
And similarly 'systemctl disable' would do nothing if the unit was enabled in
/run. This just doesn't seem useful.
This pathch changes enable/disable and mask/unmask to be asymmetrical. enable
and mask create symlinks in /etc or /run, depending on whether --runtime was
specified. disable and unmask remove symlinks from both locations. --runtime
cannot be specified for the disable and unmask verbs.
The advantage is that 'disable' now means that the unit is disabled, period.
And similarly for 'unmask', all masks are removed.
Similarly for preset and preset-all, they now cannot be called with --runtime,
and are asymmetrical: when they enable a unit, symlinks are created in /etc.
When they disable a unit, all symlinks are nuked.
$ systemctl --root=/ enable bluetooth
Created symlink /etc/systemd/system/dbus-org.bluez.service → /usr/lib/systemd/system/bluetooth.service.
Created symlink /etc/systemd/system/bluetooth.target.wants/bluetooth.service → /usr/lib/systemd/system/bluetooth.service.
$ systemctl --root=/ --runtime enable bluetooth
Created symlink /run/systemd/system/dbus-org.bluez.service → /usr/lib/systemd/system/bluetooth.service.
Created symlink /run/systemd/system/bluetooth.target.wants/bluetooth.service → /usr/lib/systemd/system/bluetooth.service.
$ systemctl --root=/ disable bluetooth
Removed /run/systemd/system/bluetooth.target.wants/bluetooth.service.
Removed /run/systemd/system/dbus-org.bluez.service.
Removed /etc/systemd/system/bluetooth.target.wants/bluetooth.service.
Removed /etc/systemd/system/dbus-org.bluez.service.
$ systemctl --root=/ disable --runtime bluetooth
--runtime cannot be used with disable
$ systemctl --root=/ mask --runtime bluetooth
Created symlink /run/systemd/system/bluetooth.service → /dev/null.
$ systemctl --root=/ mask bluetooth
Created symlink /etc/systemd/system/bluetooth.service → /dev/null.
$ systemctl --root=/ unmask bluetooth
Removed /run/systemd/system/bluetooth.service.
Removed /etc/systemd/system/bluetooth.service.
$ systemctl --root=/ unmask --runtime bluetooth
--runtime cannot be used with unmask
$ systemctl --root=/ --runtime enable bluetooth
Created symlink /run/systemd/system/dbus-org.bluez.service → /usr/lib/systemd/system/bluetooth.service.
Created symlink /run/systemd/system/bluetooth.target.wants/bluetooth.service → /usr/lib/systemd/system/bluetooth.service.
$ systemctl --root=/ enable bluetooth
Created symlink /etc/systemd/system/dbus-org.bluez.service → /usr/lib/systemd/system/bluetooth.service.
Created symlink /etc/systemd/system/bluetooth.target.wants/bluetooth.service → /usr/lib/systemd/system/bluetooth.service.
$ systemctl --root=/ preset bluetooth
Removed /run/systemd/system/bluetooth.target.wants/bluetooth.service.
Removed /run/systemd/system/dbus-org.bluez.service.
Removed /etc/systemd/system/bluetooth.target.wants/bluetooth.service.
Removed /etc/systemd/system/dbus-org.bluez.service.
$ systemctl --root=/ preset --runtime bluetooth
--runtime cannot be used with preset
$ systemctl preset-all --runtime
--runtime cannot be used with preset-all
This rewords the section, explicitly distuingishing the cases of clients
that only want a continious log stream (which can simply treat
SD_JOURNAL_INVALIDATE the same way as SD_JOURNAL_APPEND) and those which
want to represent on screen the full state of the log data on disk.
This is an alternative to a part of PR #9060, but keeps an explanation
of the destinction of handling depending on the type of client.
Fixes: #8963
We currently return -ENOMEDIUM when /etc/machine-id is empty, and -EINVAL when
it is all zeros. But -EINVAL is also used for invalid args. The distinction
between empty and all-zero is not very important, let's use the same return
code.
Also document -ENOENT and -ENOMEDIUM since they can be a bit surprising.
This corresponds nicely with the specifiers we already pass for
/var/lib, /var/cache, /run and so on.
This is particular useful to update the test-path service files to
operate without guessable files, thus allowing multiple parallel
test-path invocations to pass without issues (the idea is to set $TMPDIR
early on in the test to some private directory, and then only use the
new %T or %V specifier to refer to it).
Usually, we order our settings in our unit files in a logical order,
grouping related settings together, and putting more relevant stuff
first, instead of following a strictly alphabetical order.
For specifiers I think it makes sense to follow an alphabetical order
however, since they literally are just characters, and hence I think the
concept of alphabetical ordering is much more commanding for them. Also,
since specifiers are usually not used in combination, but mostly used
indepdently of each other I think it's not that important to group
similar ones together.
No other changes except the reordering.
When dealing with a large number of template instances, for example
when launching daemons per VRF, it is hard for operators to correlate
log lines to arguments.
Add a new with-unit mode which, if available, prefixes unit and user
unit names when displaying its log messages instead of the syslog
identifier. It will also use the full timestamp with timezones, like
the short-full mode.
sysexits.h has:
#define EX_CANTCREAT 73 /* can't create (user) output file */
EX_DATAERR is a copy-paste error from the previous sentence, which is
correct.
Similar as the other options added before, this is primarily useful to
provide comprehensive OCI runtime compatbility, but might be useful
otherwise, too.
This simply controls the PR_SET_NO_NEW_PRIVS flag for the container.
This too is primarily relevant to provide OCI runtime compaitiblity, but
might have other uses too, in particular as it nicely complements the
existing --capability= and --drop-capability= flags.
Previously, the container's hostname was exclusively initialized from
the machine name configured with --machine=, i.e. the internal name and
the external name used for and by the container was synchronized. This
adds a new option --hostname= that optionally allows the internal name
to deviate from the external name.
This new option is mainly useful to ultimately implement the OCI runtime
spec directly in nspawn, but it might be useful on its own for some
other usecases too.
This ensures we set the various resource limits of our container
explicitly on each invocation so that we inherit less from our callers
into the payload.
By default resource limits are now set to the same values Linux
generally passes to the host PID 1, thus minimizing needless differences
between host and container environments.
The limits are now also configurable using a new --rlimit= switch. This
is preparation for teaching nspawn native OCI runtime support as OCI
permits setting resource limits for container payloads, and it hence
probably makes sense if we do too.
What the man page said was different than what the code did.
save_external_coredump() will store the core temporarily for backtrace
generation, and will delete if afterwards if it is too large. So to disable
processing, it's necessary to both set
Storage=none/Storage=journal+JournalSizeMax=0/Storage=external+ExternalSizeMax=0
and ProcessSizeMax=0. This updates the man page to reflect the code.
The man pages are extended to describe that Storage=none + ProcessSizeMax=0 is
the simplest way to disable coredump processing. All the storage and processing
options make this quite complicated, so let's add a copy-and-pasteable example
of how to disable coredump. Doing it through coredump.conf has the advantage
that we still log, and the effect is immediate, unlike masking the sysconf
file.
Fixes#8788.
Commenting out "WatchdogTimeout=3min" in systemd-logind.service causes
NotifyAccess to go from "main" to "none", breaking support for logind
restart. Let's fix that.
Since StandardOutput=file:path is more similar to StandardInput= than
StandardInputText=, and only StandardInput= is actually documented above
StandardOutput= whereas StandardInputText= is documented below it, I
assume the intention was to refer to the former.
While set of systemd-journal-{gatewayd,remote,upload}.service services presents single subsystem on journald logs network transmission, systemd-journal-gatewayd.service description should also contain links to other parts of this subsystem: systemd-journal-remote.service and systemd-journal-upload.service.
* man: systemd-networkd-wait-online: systemd.service
While service type is mentioned (is a oneshot system service), link on systemd.service is added. 'See Also' section is also updated with link on systemd.service man-page.
Added short keys -u and -m for --unescape and --mangle respectively. These short keys are present in systemd-escape --help output and are absent in man systemd-escape page.
Add journal-upload.conf refentrytitle to have the same format to systemd-journal-remote.service description, which contains refentrytitle on journal-remote.conf in 'See Also' section.
This patch add support to enables to send User Class option code 77
RFC 3004.
This option MAY carry multiple User Classes.
The format of this option is as follows:
Code Len Value
+-----+-----+--------------------- . . . --+
| 77 | N | User Class Data ('Len' octets) |
+-----+-----+--------------------- . . . --+
where Value consists of one or more instances of User Class Data.
Each instance of User Class Data is formatted as follows:
UC_Len_i User_Class_Data_i
+--------+------------------------ . . . --+
| L_i | Opaque-Data ('UC_Len_i' octets) |
+--------+------------------------ . . . --+
UserClass=
A DHCPv4 client can use UserClass option to identify the type or category of user or applications
it represents. The information contained in this option is an string that represents the user class
of which the client is a member. Each class sets an identifying string of information to be used by the DHCP service to classify clients. Takes a whitespace-separated list.
UserClass= hello world how are you
Closes: RFC: #5134
Our CODING_STYLE document suggests to suffix all paths referring to dirs
rather than regular files with a "/" in our docs and log messages.
Update file-hierarchy(7) to do just that.
No other changes.
We document this further down in the text, but let's also list this
early on, where we mention the FHS as major influence too, so that it is
clear we incorporate all that thinking.
Previously, reading through systemd.exec(5) one might get the idea that
XDG_SEAT and XDG_VTNR are part of the service management logic, but they
are not, they are only set if pam_systemd is part of a PAM stack an
pam_systemd is used.
Hence, let's drop these env vars from the list of env vars, and instead
add a paragraph after the list mentioning that pam_systemd might add
more systemd-specific env vars if included in the PAM stack for a
service that uses PAMName=.
Rather than choosing to set or unset any of these flag
use kernel defaults. This patch makes following properties to unset.
UseBPDU = unset
HairPin = unset
FastLeave = unset
AllowPortToBeRoot = unset
UnicastFlood = unset
This implements similar logic as conf_files_cat(), but with slightly different
file gathering logic. I also want to add support for replacement files later on,
so it seems better to keep those two file-gathering functions separate.
This is used as 'systemd-analyze show-config systemd/logind.conf', which
will dump
/etc/systemd/system/user@.service
/etc/systemd/system/user@.service.d/*.conf
/run/systemd/system/user@.service.d/*.conf
/usr/local/lib/systemd/system/user@.service.d/*.conf
/usr/lib/systemd/system/user@.service.d/*.conf
The idea is to make it easy to dump the configuration using the same locations
and order that systemd programs use themselves (including masking, in the right
order, etc.). This is the generic variant that works with any configuration
scheme that follows the same general rules:
$ systemd-analyze cat-config systemd/system.conf
$ systemd-analyze cat-config systemd/user.conf
$ systemd-analyze cat-config systemd/logind.conf
$ systemd-analyze cat-config systemd/sleep.conf
$ systemd-analyze cat-config systemd/journald.conf
$ systemd-analyze cat-config systemd/journal-remote.conf
$ systemd-analyze cat-config systemd/journal-upload.conf
$ systemd-analyze cat-config systemd/coredump.conf
$ systemd-analyze cat-config systemd/resolved.conf
$ systemd-analyze cat-config systemd/timesyncd.conf
$ systemd-analyze cat-config udev/udev.conf
This removes the UserTasksMax= setting in logind.conf. Instead, the generic
TasksMax= setting on the slice should be used. Instead of a transient unit we
use a drop-in to tweak the default definition of a .slice. It's better to use
the normal unit mechanisms instead of creating units on the fly. This will also
make it easier to start user@.service independently of logind, or set
additional settings like MemoryMax= for user slices.
The setting in logind is removed, because otherwise we would have two sources
of "truth": the slice on disk and the logind config. Instead of trying to
coordinate those two sources of configuration (and maintainer overrides to
both), let's just convert to the new one fully.
Right now now automatic transition mechanism is provided. logind will emit a
hint when it encounters the setting, but otherwise it will be ignored.
Fixes#2556.
Those are quite similar to %i/%I, but refer to the last dash-separated
component of the name prefix.
The new functionality of dash-dropins could largely supersede the template
functionality, so it would be tempting to overload %i/%I. But that would
not be backwards compatible. So let's add the two new letters instead.
The description in the man page disagreed with the code. Let the code win,
since if anybody is using this, they are more likely to depend on actual
behaviour rather than the docs. (In Fedora workstation installation there's
only one use, and it doesn't make much sense either way: SyslogIdentifier=%N
in xfs_scrub@.service.)
Also adds dots at the end everywhere, because we have multiple sentences in
some explanations, so we need dots.
- Add a new flag --strict to tell systemd-hwdb to return a
non-zero code on error.
- Make systemd-hwdb update return an error when any parsing
error occurs (only if strict flag is set).
Newer terminals (in particular gnome-terminal) understand special escape
sequence for formatting clickable links. Let's support that to make our
tool output more clickable where that's appropriate.
For details see this:
https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
The one big issue is that 'less' currently doesn't grok this, and
doesn't ignore sequence like regular terminal implementations do if they
don't support it. Hence for now, let's disable URL output if a pager is
used. We should revisit that though as soon as less added support for it
and enough time passed for it to enter various distributions.
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.
It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
First of all, it's frickin' ugly and wrong, as IPC sockets should be
placed in /run and definitely not under a guessable name under
world-writable /tmp. Secondly, it can't even work as we set
PrivateTmp=yes on the service.
Hence, let's clean up the example, and simply use a socket in /run
instead.
Fixes: #8419
We have a common parser, but for the user it might be
completely unobvious that the same general rules apply
to all those files. Let's add a page about the basic syntax
so that the more specific pages don't have to repeat those
details.
Absolute paths make everything simple and quick, but sometimes this requirement
can be annoying. A good example is calling 'test', which will be located in
/usr/bin/ or /bin depending on the distro. The need the provide the full path
makes it harder a portable unit file in such cases.
This patch uses a fixed search path (DEFAULT_PATH which was already used as the
default value of $PATH), and if a non-absolute file name is found, it is
immediately resolved to a full path using this search path when the unit is
loaded. After that, everything behaves as if an absolute path was specified. In
particular, the executable must exist when the unit is loaded.
Systems that have an accurate real-time clock may have an initial
unsynchronized time that is close enough to the synchronized time that
the final adjustment doesn't trigger a waking "clock set" event. Have
timesyncd touch a file in its runtime directory as a secondary signal
for synchronization. Continue to support the timerfd-based trigger as a
sufficient condition when the watchfile is not present.
Closes issue #8683
Clarify the helper/checker terminology in the systemd-fsck@.service manpage to
make the description more clear about what is responsible for deciding if a filesystem
needs checking.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Things can fail, and we have no control over it:
- file system issues (immutable bits, file system errors, MAC refusals, etc)
- kernel refusing certain arguments when writing to /proc/sys or /sys
Let's add a new code for the case where we parsed configuration but failed
to execute it because of external errors.
Fixes#5387.
I kept the _SYSTEMD_UNIT= example because it is easy to understand and
not very verbose. _SYSTEMD_CGROUP has much longer entries which do not
fit well in the narrow man page. Instead, I added an explanation of what
-u is translated into.
Lion Yang