As a follow-up for db3f45e2d2 let's do the
same for all other cases where we create a FILE* with local scope and
know that no other threads hence can have access to it.
For most cases this shouldn't change much really, but this should speed
dbus introspection and calender time formatting up a bit.
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.
Check if the parsed seconds value fits in an integer *after*
multiplying by USEC_PER_SEC, otherwise a large value can trigger
modulo by zero during normalization.
strtoul() parses leading whitespace and an optional sign;
check that the first character is a digit to prevent odd
specifications like "00: 00: 00" and "-00:+00/-1".
"*-*~1" => The last day of every month
"*-02~3..5" => The third, fourth, and fifth last days in February
"Mon 05~07/1" => The last Monday in May
Resolves#3861
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.
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.
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.
Some places invoked fflush() directly with their own manual error
checking, let's unify all that by using fflush_and_check().
This also unifies the general error paths of fflush()+rename() file
writers.
