Quoting https://github.com/systemd/systemd/pull/8760#discussion_r183321060:
> When we originally added the errno patching we went for a "best of both
> worlds" approach, i.e. that we override errno if an error is specified, but
> if no error is specified (i.e. 0 is passed as error code) then we use the
> previously set errno, similar in style how plain `printf()` would do it. In
> retrospect I think we almost never purposefully made use of the second,
> i.e. the plain `printf()` logic, but we multiple times ran into this case
> accidentally and introduced a bug. Hence yes, it probably makes sense to
> switch this over, and consistently ignore the `errno` already set and always
> override it with the error passed in. The only problem I see with that is: I
> wonder if there might be a case or two lurking somewhere where we actually
> made use of the "best of both worlds" approach, and if so, if we can detect
> where... (But then again, even if there is, and we fail to find those cases,
> maybe that's not all bad, as it's just a few new bugs against probably fixing
> many more old and future bugs, if you follow what I mean).
I scanned our codebase, and found some bugs in the value passed to log_*_errno,
but no intentional cases of error=0 being passed.
We don't know what the container payload needs, hence default to a PATH
with both bin and sbin included, as well as / and /usr.
Follow-up for #8324Fixes: #8698
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.
To indicate that the there're no more entries, these wrappers return false but
did leave the passed pointed unmodified.
However EOF is not an error and is a very common case so initialize the output
argument to NULL even in this case so callers don't need to do that.
Fixes: #8721
We check the same condition at various places. Let's add a trivial,
common helper for this, and use it everywhere.
It's not going to make things much faster or much shorter, but I think a
lot more readable
If the flag is set only a single step of the normalization is executed,
and the resulting path is returned.
This allows callers to normalize piecemeal, taking into account every
single intermediary path of the normalization.
We have plenty of code in our codebase that outputs tables to the
console, and all is homegrown and awful. Let's replace it with a generic
implementation that can do automatically what the old implementations
did manually.
Features:
1. Ellipsation (for fields overly long) and alignment (for
fields overly short)
2. Sorting of rows
3. automatically copies formatting from the same cell in the row above
4. Heavy use of varargs to make putting together tables easy
5. can expand and compress tables, with weights
6. Has a minimal understanding of unicode wide characters in order to
match unicode strings to character cell terminals.
7. Columns can be reordered and individually turned off.
8. pretty printing for various data types
And more.
pager.[ch] doesn't use any APIs from src/libsystemd/ or src/shared/
hence there's no reason for it to be in src/shared/, let's move it to
src/basic/ instead.
This enables us to use pager.[ch] APIs from other code in src/basic/,
for example pager_have() and suchlike.
This primarily changes to things:
1. Ellipsation to 0, 1 or 2 characters is now supported. Previously we'd
hit an assert if the new lengths was < 3, this is now permitted. The
result strings won't show too much info still of course, but the code
becomes a bit more generic and robust to use.
2. If a UTF-8 mode is disabled and the input string is pure ASCII, then
"..." is used for ellipsation, otherwise (as before) "…". This means
on a pure-ASCII system we should remain pure-ASCII, matching
behaviour otherwise exposed with special_glyph() and friends. Note
that we'll use "…" for ellipsiation as soon as either the locale
settings indicate an UTF-8 mode or the input string already contains
non-ASCII unicode characters.
Testing for these special cases is improved.
The NULSTR_FOREACH iterator needs to see an empty string at the end, so
we need to insert an extra NUL explicitly.
Also update PATH0_BIN_SBIN(x) to include an extra NUL terminator, rename
it to PATH_BIN_SBIN_NULSTR(x), which is more consistent with the similar
CONF_PATHS_NULSTR(x) macro.
Fixes: 5008da1ec1
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.
If a tool only invokes copy_bytes() a single time the _unlikely_() will always be
wrong, and is hence not useful. Let's drop it and let the compiler
figure our what to do, instead of misleading it.
Also, some coding style imprvoements.
splice() ignores O_NONBLOCK on pipes but not on other fds. Let's handle
that properly, and query O_ONBLOCK manually in that case, ensuring
systematic behaviour in either case.
Optionally, when we copy between fds with simple read/write, let's
return any remaining data we already read into the buffer if write
fails. This is useful to allow callers to use the read data otherwise,
perhaps implementing a different fallback for copying.
It does two things:
1. It derives the element size from the array argument type
2. It derives the right type for the function from the array argument
type
Using this macro call should make the invocations of qsort() quite a bit
safer.
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.
Accept definitions to other AF_ constants, not just PF_ ones,
such as:
#define AF_LINUX AF_LOCAL
It may not be necessary to impose any restriction on the
definitions of the macros extracted, but for now
keep most of that requirement but match AF_* as well.
Zbigniew Jędrzejewski-Szmek
Milan
Yu Watanabe
Lennart Poettering
Franck Bui
Filipe Brandenburger
Will Dietz