Also called "ANSI-C Quoting" in info:(bash) ANSI-C Quoting.
The escaping rules are a POSIX proposal, and are described in
http://austingroupbugs.net/view.php?id=249. There's a lot of back-and-forth on
the details of escaping of control characters, but we'll be only using a small
subset of the syntax that is common to all proposals and is widely supported.
Unfortunately dash and fish and maybe some other shells do not support it (see
the man page patch for a list).
This allows environment variables to be safely exported using show-environment
and imported into the shell. Shells which do not support this syntax will have
to do something like
export $(systemctl show-environment|grep -v '=\$')
or whatever is appropriate in their case. I think csh and fish do not support
the A=B syntax anyway, so the change is moot for them.
Fixes#5536.
v2:
- also escape newlines (which currently disallowed in shell values, so this
doesn't really matter), and tabs (as $'\t'), and ! (as $'!'). This way quoted
output can be included directly in both interactive and noninteractive bash.
Per man:file-hierarchy(7), /lib is just a compatibility symlink; the
other manpages also refer to /usr/lib.
Found with:
git grep -P '(?<!/usr|/var|local)/lib' man/
'systemctl --failed' is an extremely common operation and it's nice to have
a shortcut for it.
Revert "man: don't document systemctl --failed" and add the option back to
systemctl's help and shell completion scripts.
This reverts commit 036359ba8d.
- Show example of all `systemctl status` output and documents what possible
"Loaded:", "Active" and "Enabled" values mean.
- Documents what different colors of the dot mean.
- Documents "gotcha" with load-on-demand behavior which will report units as
"loaded" even if they are only loaded to show their status.
(From @poettering: https://github.com/systemd/systemd/issues/5063#issuecomment-272115024 )
When a user is trying to understand what is going on with a restart action, it is useful to explicitly describe how the action is run. It may seem obvious, but it is helpful to be explicit so one knows there isn't a special ExecRestart= or similar option that they could be looking at.
As requested in
https://github.com/systemd/systemd/pull/4864#pullrequestreview-12372557.
docbook will substitute triple dots for the ellipsis in man output, so this has
no effect on the troff output, only on HTML, making it infinitesimally nicer.
In some places we show output from programs, which use dots, and those places
should not be changed. In some tables, the alignment would change if dots were
changed to the ellipsis which is only one character. Since docbook replaces the
ellipsis automatically, we should leave those be. This patch changes all other
places.
It may be desired by users to know what targets a particular service is
installed into. Improve user friendliness by teaching the is-enabled
command to show such information when used with --full.
This patch makes use of the newly added UnitFileFlags and adds
UNIT_FILE_DRY_RUN flag into it. Since the API had already been modified,
it's now easy to add the new dry-run feature for other commands as
well. As a next step, --dry-run could be added to systemctl, which in
turn might pave the way for a long requested dry-run feature when
running systemctl start.
This adds two (privileged) bus calls Ref() and Unref() to the Unit interface.
The two calls may be used by clients to pin a unit into memory, so that various
runtime properties aren't flushed out by the automatic GC. This is necessary
to permit clients to race-freely acquire runtime results (such as process exit
status/code or accumulated CPU time) on successful service termination.
Ref() and Unref() are fully recursive, hence act like the usual reference
counting concept in C. Taking a reference is a privileged operation, as this
allows pinning units into memory which consumes resources.
Transient units may also gain a reference at the time of creation, via the new
AddRef property (that is only defined for transient units at the time of
creation).
The man pages didn't ever mention that symlinks to units can be created, and what
exactly this means. Fix that omission, and disallow presets on alias names.
To "search something", in the meaning of looking for it, is valid,
but "search _for_ something" is much more commonly used, especially when
the meaning could be confused with "looking _through_ something"
(for some other object).
(C.f. "the police search a person", "the police search for a person".)
Also reword the rest of the paragraph to avoid using "automatically"
three times.
Clarify that "systemctl enable" can operate either on unit names or on unit
file paths (also, adjust the --help text to clarify this). Say that "systemctl
enable" on unit file paths also links the unit into the search path.
Many other fixes.
This should improve the documentation to avoid further confusion around #3706.
When "preset" was executed for a unit without install info, we'd warn similarly
as for "enable" and "disable". But "preset" is usually called for all units,
because the preset files are provided by the distribution, and the units are under
control of individual programs, and it's reasonable to call "preset" for all units
rather then try to do it only for the ones that can be installed.
We also don't warn about missing info for "preset-all". Thus it seems reasonable
to silently ignore units w/o install info when presetting.
(In addition, when more than one unit was specified, we'd issue the warning
only if none of them had install info. But this is probably something to fix
for enable/disable too.)
This allows dropping all user configuration and reverting back to the vendor
default of a unit file. It basically undoes what "systemctl edit", "systemctl
set-property" and "systemctl mask" do.
Now, that the search path logic knows the unit path for transient units we also
can introduce an explicit unit file state "transient" that clarifies to the
user what kind of unit file he is encountering.
Now that we store the generator directories in LookupPaths we can use this to
intrdouce a new unit file state called "generated", for units in these
directories.
Fixes: #2348
With this option, systemctl will only print the rhs in show:
$ systemctl show -p Wants,After systemd-journald --value
systemd-journald.socket ...
systemd-journald-dev-log.socket ...
This is useful in scripts, because the need to call awk or similar
is removed.
The "is-enabled" command doesn't care whether the symlinks are declared in the
[Install] section of a unit file or not, when returning "enabled". Any alias,
.wants/ or .requires/ symlinks suffice.
Fixes: #975
But also keep the old name as (undocumented) compatibility around.
The reload-or-try-restart was documented to be a NOP if the unit is not running, since the previous commits this is
also implemented. The old name suggests that the "try" logic only applies to restarting. Fix this, by moving the "try-"
to the front, to indicate that the whole option is a NOP if the service isn't running.
