*scanf functions set errno on i/o error. For sscanf, this doesn't really apply,
so (based on the man page), it seems that errno is unlikely to be ever set to a
useful value. So just ignore errno. The error message includes the string that
was parsed, so it should be always pretty clear why parsing failed.
On the other hand, detect trailing characters and minus prefix that weren't
converted properly. This matches what our safe_ato* functions do. Add tests to
elucidate various edge cases.
usec_t is always 64bit, which means it can cover quite a number of
years. However, 4 digit year display and glibc limitations around time_t
limit what we can actually parse and format. Let's make this explicit,
so that we never end up formatting dates we can#t parse and vice versa.
Note that this is really just about formatting/parsing. Internal
calculations with times outside of the formattable range are not
affected.
Passing a year such as 1960 to mktime() will result in a negative return
value. This is quite confusing, as the man page claims that on failure
the call will return -1...
Given that our own usec_t type is unsigned, and we can't express times
before 1970 hence, let's consider all negative times returned by
mktime() as invalid, regardless if just -1, or anything else negative.
gcc 7 adds -Wimplicit-fallthrough=3 to -Wextra. There are a few ways
we could deal with that. After we take into account the need to stay compatible
with older versions of the compiler (and other compilers), I don't think adding
__attribute__((fallthrough)), even as a macro, is worth the trouble. It sticks
out too much, a comment is just as good. But gcc has some very specific
requiremnts how the comment should look. Adjust it the specific form that it
likes. I don't think the extra stuff we had in those comments was adding much
value.
(Note: the documentation seems to be wrong, and seems to describe a different
pattern from the one that is actually used. I guess either the docs or the code
will have to change before gcc 7 is finalized.)
Let's accept "µs" as alternative time unit for microseconds. We already accept
"us" and "usec" for them, lets extend on this and accept the proper scientific
unit specification too.
We will never output this as time unit, but it's fine to accept it, after all
we are pretty permissive with time units already.
This patch improves parsing and generation of timestamps and calendar
specifications in two ways:
- The week day is now always printed in the abbreviated English form, instead
of the locale's setting. This makes sure we can always parse the week day
again, even if the locale is changed. Given that we don't follow locale
settings for printing timestamps in any other way either (for example, we
always use 24h syntax in order to make uniform parsing possible), it only
makes sense to also stick to a generic, non-localized form for the timestamp,
too.
- When parsing a timestamp, the local timezone (in its DST or non-DST name)
may be specified, in addition to "UTC". Other timezones are still not
supported however (not because we wouldn't want to, but mostly because libc
offers no nice API for that). In itself this brings no new features, however
it ensures that any locally formatted timestamp's timezone is also parsable
again.
These two changes ensure that the output of format_timestamp() may always be
passed to parse_timestamp() and results in the original input. The related
flavours for usec/UTC also work accordingly. Calendar specifications are
extended in a similar way.
The man page is updated accordingly, in particular this removes the claim that
timestamps systemd prints wouldn't be parsable by systemd. They are now.
The man page previously showed invalid timestamps as examples. This has been
removed, as the man page shouldn't be a unit test, where such negative examples
would be useful. The man page also no longer mentions the names of internal
functions, such as format_timestamp_us() or UNIX error codes such as EINVAL.
We already have a double timestamp object that we use whenever we need both a
MONOTONIC and a REALTIME timestamp taken and stored. With this change we
also add a triple timestamp object that in addition stores a BOOTTIME
timestamp, which is useful for a few usecases.
Note that we keep dual_timestamp around, as it is useful in many cases where
triple_timestamp is not, in particular because retrieving the monotonic and
realtime timestamps is much cheaper on Linux that getting the boottime
timestamp.
Before we invoke now(CLOCK_BOOTTIME), let's make sure we actually have that
clock, since now() will otherwise hit an assert.
Specifically, let's refuse CLOCK_BOOTTIME early in sd-event if the kernel
doesn't actually support it.
This is a follow-up for #3037, and specifically:
https://github.com/systemd/systemd/pull/3037#issuecomment-210199167
It was added in 2.6.39, and causes an assertion to fail when running in mock
hosted on 2.6.23-based RHEL-6:
Assertion 'clock_gettime(map_clock_id(clock_id), &ts) == 0' failed at systemd/src/basic/time-util.c:70, function now(). Aborting.
Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands. Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.
The deserialize_timestamp_value() is renamed timestamp_deserialize() to be more
consistent with dual_timestamp_deserialize()
And add the NULL check back on realtime and monotonic
The time-util.c provides dual_timestamp_deserialize() function to
convert value to usec_t and set it as value of ts->monotonic and
ts->realtime.
There are some places in code which do the same but only for one
clockid_t (realtime or monotonic), when dual_timestamp_deserialize()
sets value of both.
This patch introduces the deserialize_timestamp_value() which converts
a given value to usec_t and write it to a given timestamp.
The dual_timestamp_from_realtime(), dual_timestamp_from_monotonic()
and dual_timestamp_from_boottime_or_monotonic() shares the same
code for comparison given ts with delta. Let's move it to the
separate inline function to prevent code duplication.
The time_util.c provides format_timestamp_internal() and
format_timestamp_internal_us() functions for a timestamp formating. Both
functions are very similar and differ only in formats handling.
We can add additional boolean parameter to the format_timestamp_internal()
function which will represent is a format for us timestamp or not.
This allows us to get rid of format_timestamp_internal_us() that is prevent
code duplication.
We can remove format_timestamp_internal_us() safely, because it is static and
has no users outside of the time_util.c. New fourth parameter will be passed
inside of the format_timestamp(), format_timestamp_us() and etc, functions,
but the public API is not changed.
The time-util.c provides dual_timestamp_get() function for getting
realtime and monotonic timestamps. Let's use it instead of direct
realtime/monotonic calculation.
nginx defines an uppercase "M" that way (in contrast to the lowercase
"m" for "minute"), and it sounds like an OK logic to follow, so that we
understand a true superset of time values nginx understands.
http://nginx.org/en/docs/syntax.html
This is useful if we want to parse RLIMIT_RTTIME values where the common
UNIX syntax is without any units but refers to a non-second unit (µs in
this case), but where we want to allow specification of units.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
In preparation of the unified cgroup support, let's clean up cgtop:
a) rework time code to be based on "nsec_t" rather than "struct timespec"
b) Introduce long option --order= for selecting ordering
c) count number of processes only in the main hierarchy, don't bother
with the controller hierarchies. We don't allow orthogonal
hierarchies in systemd anymore, hence there's no point to check the
other hierarchies.
d) Deal with non-monotonic cpuacct values (see #749)
e) When sorting groups, don't do prefix compare when ordering by number
of tasks, since this is not accumulative for all children.
f) Actually make --cpu without parameter work
g) Don't output control characters when we get them as input.
Fixes#749.
Some of the operations machined/machinectl implement are also very
useful when applied to the host system (such as machinectl login,
machinectl shell or machinectl status), hence introduce a pseudo-machine
by the name of ".host" in machined that refers to the host system, and
may be used top execute operations on the host system with.
This copies the pseudo-image ".host" machined already implements for
image related commands.
(This commit also adds a PK privilege for opening a PTY in a container,
which was previously not accessible for non-root.)
