rc.subr(8): Fix markup -- use .It to set off a new item.

Bump date for previous and remove trailing whitespace.

Add shell implementations of basename and dirname to rc.subr. They
are supposed to mimic basename(1) and dirname(1), except that they
are usable before /usr/bin is mounted.

branches: 1.29.2; 1.29.8;
Allow "echo -n" to work as expected in rc.d scripts that are executed
by /etc/rc. Similarly for printf with a format that does not end with
"\n". Previously, the partial line would not be visible on the console
until a newline was printed, possibly after an annoying delay.

This is done by adding echo() and printf() shell functions to rc.subr,
so that naive use of the echo and printf commands in rc.d scripts will
call these functions instead of the underlying commands. These shell
functions send a new "nop" metadata message after the partial line, and
the rc_postprocess function in /etc/rc disentangles the partial line of
plain output from the metadata "nop".

Also add a "-n" option to the print_rc_normal function in rc.subr,
and make some cosmetic changes.

Bump date for previous

Add a collapse_backslash_newline function to rc.subr.

Document that run_rc_command can take extra parameters and will pass those
to the command being executed.

Typo in macro name (.Is -> .Ic), noticed by joerg@

Bump date for previous. Whitespace nit. Use Nm instead of Xr to itself.

Add a postprocessor to /etc/rc, which logs messages to /var/run/rc.log,
and which can suppress output in silent mode. Silent mode is enabled
via the new rc_silent variable, which defaults to a value that depends
on the kern.boothowto sysctl.

Part of the /etc/rc silent changes requested in PR 41946
and proposed in tech-userlevel.

Don't use .Xo/.Xc to workaround argument limit in ancient groff.

branches: 1.21.2; 1.21.4;
Bump date for previous.

Document the new ${name}_env feature: list of new or modified environment
variables to set when starting ${command}.

branches: 1.19.2;
Convert TNF licenses to new 2 clause variant

branches: 1.18.4; 1.18.6;
Remove systrace. Ok core@.

branches: 1.17.4;
* Add a stop_boot() function in rc.subr, to terminate a multi-user boot
by killing the parent process. The parent's PID is saved in $RC_PID.
* In all rc.d/* scripts that previously tried to stop the boot,
replace in-line code with "stop_boot".
* Document this.

This should fix PR 29822.

* Implement
load_rc_config_var cmd var
to load the rc.conf(5) configuration for cmd and set var in the
current shell, using 'load_rc_config var' in a sub-shell to avoid
unwanted side-effects.

* Improve required_vars warning message.

Flasg -> Flags

Simplify sentence.

Introduce and use the rcvar_manpage variable, which contains the manual page
name where the user should look at for documentation about rcvar. It defaults
to 'rc.subr(5)', as rc.subr is mainly used by rc.d scripts.

This variable is useful to let the daily, weekly, monthly and security scripts
tune the warning message shown when any of the variables they handle is not
properly set.

Closes PR misc/23908.

branches: 1.12.4;
Implement ``one'' prefix to allow a "one shot" operation as if
${rcvar}=yes yet all the other prerequisite tests are still performed.
The existing ``force'' prefix is a sledgehammer that ignores all the
prerequisite checks and always returns a zero exit status; this is a
more gentle approach to the problem of "manipulate this disabled
service without editing rc.conf(5)".

Drop trailing whitespace. Reviewed by wiz.

successful with only one l.

Add systrace(1) support to rc.subr. Most services (eg, ${name} is
inetd) started from rc can now be run under systrace by setting
${name}_systrace to a set of flags to be passed to systrace. Note
that policies need to generated before you do this.

minor improvements, including consistency in how variables are formatted.

Replace $critical_filesystems_beforenet with $critical_filesystems_local .
Replace $critical_filesystems with $critical_filesystems_remote .

The new names are now consistent with the type argument that
mount_critical_filesystems() is called with, and allows for other types to
be easily supported by that function.

For backwards compatibility purposes, if the now obsolete variable is defined
(even empty), it takes precedence over the new form, and you will be warned.
If you want to stop the warnings, update your rc.conf(5) settings!

- document optional "interpreter" argument to check_pidfile() and
check_process()
- document rc_* variables available in method and after run_rc_command()
completes

document $command_interpreter

document ${_arg}_postcmd

Punctuation nits.

Fixes derived from [bin/15563] submitted by Ron Roskens:
- Don't su(1) to ${name}_user if running as that user.
- Support $procname as the name of the process to search for.
Defaults to the value of $command.

rc.subr(8) - functions used by system shell scripts. Closes PR [misc/10828].