... when called with a valid environment variable name. This means that
any time we call it with a fixed string, it is guaranteed to return 0.
(Also when the variable is not present in the environment block.)
User records have the realname/gecos fields, groups never had that, but
it would really be useful to have it, hence let's add it with similar
semantics.
We enforce the same syntax as for GECOS, since it's better to start with
strict rules and losen them later instead of the opposite.
Presently, CLI utilities such as systemctl will check whether they have a tty
attached or not to decide whether to parse /proc/cmdline or EFI variable
SystemdOptions looking for systemd.log_* entries.
But this check will be misleading if these tools are being launched by a
daemon, such as a monitoring daemon or automation service that runs in
background.
Make log handling of CLI tools uniform by never checking /proc/cmdline or EFI
variables to determine the logging level.
Furthermore, introduce a new log_setup_cli() shortcut to set up common options
used by most command-line utilities.
The userdb_by_name() invocation immediately following does the same check
anyway, no need to do this twice.
(Also, make sure we exit the function early on failure)
It fully initializes the address structure, so no need for pre-initialization,
and also returns the length of the address, so no need to recalculate using
SOCKADDR_UN_LEN().
socklen_t is unsigned, so let's not use an int for it. (It doesn't matter, but
seems cleaner and more portable to not assume anything about the type.)
The enum used for column names is integer type while table_set_display() is parsing
arguments on size_t alignment which may result in assert in table_set_display() if
the size between types missmatch. This patch cast the enums to size_t.
It also fixes all other occurences for table_set_display() and
table_set_sort().
