freebsd-skq/etc/rc.subr

# $NetBSD: rc.subr,v 1.67 2006/10/07 11:25:15 elad Exp $
# $FreeBSD$
#
# Copyright (c) 1997-2004 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Luke Mewburn.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# rc.subr
#	functions used by various rc scripts
#

: ${RC_PID:=$$}; export RC_PID

#
#	Operating System dependent/independent variables
#

if [ -z "${_rc_subr_loaded}" ]; then

_rc_subr_loaded="YES"

SYSCTL="/sbin/sysctl"
SYSCTL_N="${SYSCTL} -n"
SYSCTL_W="${SYSCTL}"
ID="/usr/bin/id"
IDCMD="if [ -x $ID ]; then $ID -un; fi"
PS="/bin/ps -ww"
JID=`$PS -p $$ -o jid=`

#
#	functions
#	---------

# list_vars pattern
#	List vars matching pattern.
# 
list_vars()
{
	set | { while read LINE; do
		var="${LINE%%=*}"
		case "$var" in
		"$LINE"|*[!a-zA-Z0-9_]*) continue ;;
		$1) echo $var
		esac
	done; }
}

# set_rcvar_obsolete oldvar [newvar] [msg]
#	Define obsolete variable.
#	Global variable $rcvars_obsolete is used.
#
set_rcvar_obsolete()
{
	local _var
	_var=$1
	debug "rcvar_obsolete: \$$1(old) -> \$$2(new) is defined"

	rcvars_obsolete="${rcvars_obsolete# } $1"
	eval ${1}_newvar=\"$2\"
	shift 2
	eval ${_var}_obsolete_msg=\"$*\"
}

#
# force_depend script [rcvar]
#	Force a service to start. Intended for use by services
#	to resolve dependency issues.
#	$1 - filename of script, in /etc/rc.d, to run
#	$2 - name of the script's rcvar (minus the _enable)
#
force_depend()
{
	local _depend _dep_rcvar

	_depend="$1"
	_dep_rcvar="${2:-$1}_enable"

	[ -n "$rc_fast" ] && ! checkyesno always_force_depends &&
	    checkyesno $_dep_rcvar && return 0

	/etc/rc.d/${_depend} forcestatus >/dev/null 2>&1 && return 0

	info "${name} depends on ${_depend}, which will be forced to start."
	if ! /etc/rc.d/${_depend} forcestart; then
		warn "Unable to force ${_depend}. It may already be running."
		return 1
	fi
}

#
# checkyesno var
#	Test $1 variable, and warn if not set to YES or NO.
#	Return 0 if it's "yes" (et al), nonzero otherwise.
#
checkyesno()
{
	eval _value=\$${1}
	debug "checkyesno: $1 is set to $_value."
	case $_value in

		#	"yes", "true", "on", or "1"
	[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
		return 0
		;;

		#	"no", "false", "off", or "0"
	[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
		return 1
		;;
	*)
		warn "\$${1} is not set properly - see rc.conf(5)."
		return 1
		;;
	esac
}

#
# reverse_list list
#	print the list in reverse order
#
reverse_list()
{
	_revlist=
	for _revfile; do
		_revlist="$_revfile $_revlist"
	done
	echo $_revlist
}

# stop_boot always
#	If booting directly to multiuser or $always is enabled,
#	send SIGTERM to the parent (/etc/rc) to abort the boot.
#	Otherwise just exit.
#
stop_boot()
{
	local always

	case $1 in
		#	"yes", "true", "on", or "1"
        [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
		always=true
		;;
	*)
		always=false
		;;
	esac
	if [ "$autoboot" = yes -o "$always" = true ]; then
		echo "ERROR: ABORTING BOOT (sending SIGTERM to parent)!"
		kill -TERM ${RC_PID}
	fi
	exit 1
}

#
# mount_critical_filesystems type
#	Go through the list of critical filesystems as provided in
#	the rc.conf(5) variable $critical_filesystems_${type}, checking
#	each one to see if it is mounted, and if it is not, mounting it.
#
mount_critical_filesystems()
{
	eval _fslist=\$critical_filesystems_${1}
	for _fs in $_fslist; do
		mount | (
			_ismounted=false
			while read what _on on _type type; do
				if [ $on = $_fs ]; then
					_ismounted=true
				fi
			done
			if $_ismounted; then
				:
			else
				mount $_fs >/dev/null 2>&1
			fi
		)
	done
}

#
# check_pidfile pidfile procname [interpreter]
#	Parses the first line of pidfile for a PID, and ensures
#	that the process is running and matches procname.
#	Prints the matching PID upon success, nothing otherwise.
#	interpreter is optional; see _find_processes() for details.
#
check_pidfile()
{
	_pidfile=$1
	_procname=$2
	_interpreter=$3
	if [ -z "$_pidfile" -o -z "$_procname" ]; then
		err 3 'USAGE: check_pidfile pidfile procname [interpreter]'
	fi
	if [ ! -f $_pidfile ]; then
		debug "pid file ($_pidfile): not readable."
		return
	fi
	read _pid _junk < $_pidfile
	if [ -z "$_pid" ]; then
		debug "pid file ($_pidfile): no pid in file."
		return
	fi
	_find_processes $_procname ${_interpreter:-.} '-p '"$_pid"
}

#
# check_process procname [interpreter]
#	Ensures that a process (or processes) named procname is running.
#	Prints a list of matching PIDs.
#	interpreter is optional; see _find_processes() for details.
#
check_process()
{
	_procname=$1
	_interpreter=$2
	if [ -z "$_procname" ]; then
		err 3 'USAGE: check_process procname [interpreter]'
	fi
	_find_processes $_procname ${_interpreter:-.} '-ax'
}

#
# _find_processes procname interpreter psargs
#	Search for procname in the output of ps generated by psargs.
#	Prints the PIDs of any matching processes, space separated.
#
#	If interpreter == ".", check the following variations of procname
#	against the first word of each command:
#		procname
#		`basename procname`
#		`basename procname` + ":"
#		"(" + `basename procname` + ")"
#		"[" + `basename procname` + "]"
#
#	If interpreter != ".", read the first line of procname, remove the
#	leading #!, normalise whitespace, append procname, and attempt to
#	match that against each command, either as is, or with extra words
#	at the end.  As an alternative, to deal with interpreted daemons
#	using perl, the basename of the interpreter plus a colon is also
#	tried as the prefix to procname.
#
_find_processes()
{
	if [ $# -ne 3 ]; then
		err 3 'USAGE: _find_processes procname interpreter psargs'
	fi
	_procname=$1
	_interpreter=$2
	_psargs=$3

	_pref=
	if [ $_interpreter != "." ]; then	# an interpreted script
		_script="${_chroot}${_chroot:+/}$_procname"
		if [ -r "$_script" ]; then
			read _interp < $_script	# read interpreter name
			case "$_interp" in
			\#!*)
				_interp=${_interp#\#!}	# strip #!
				set -- $_interp
				case $1 in
				*/bin/env)
					shift	# drop env to get real name
					;;
				esac
				if [ $_interpreter != $1 ]; then
					warn "\$command_interpreter $_interpreter != $1"
				fi
				;;
			*)
				warn "no shebang line in $_script"
				set -- $_interpreter
				;;
			esac
		else
			warn "cannot read shebang line from $_script"
			set -- $_interpreter
		fi
		_interp="$* $_procname"		# cleanup spaces, add _procname
		_interpbn=${1##*/}
		_fp_args='_argv'
		_fp_match='case "$_argv" in
		    ${_interp}|"${_interp} "*|"[${_interpbn}]"|"${_interpbn}: ${_procname}"*)'
	else					# a normal daemon
		_procnamebn=${_procname##*/}
		_fp_args='_arg0 _argv'
		_fp_match='case "$_arg0" in
		    $_procname|$_procnamebn|${_procnamebn}:|"(${_procnamebn})"|"[${_procnamebn}]")'
	fi

	_proccheck="\
		$PS 2>/dev/null -o pid= -o jid= -o command= $_psargs"' |
		while read _npid _jid '"$_fp_args"'; do
			'"$_fp_match"'
				if [ "$JID" -eq "$_jid" ];
				then echo -n "$_pref$_npid";
				_pref=" ";
				fi
				;;
			esac
		done'

#	debug "in _find_processes: proccheck is ($_proccheck)."
	eval $_proccheck
}

# sort_lite [-b] [-n] [-k POS] [-t SEP]
#	A lite version of sort(1) (supporting a few options) that can be used
#	before the real sort(1) is available (e.g., in scripts that run prior
#	to mountcritremote). Requires only shell built-in functionality.
#
sort_lite()
{
	local funcname=sort_lite
	local sort_sep="$IFS" sort_ignore_leading_space=
	local sort_field=0 sort_strict_fields= sort_numeric=
	local nitems=0 skip_leading=0 trim=

	local OPTIND flag
	while getopts bnk:t: flag; do
		case "$flag" in
		b) sort_ignore_leading_space=1 ;;
		n) sort_numeric=1 sort_ignore_leading_space=1 ;;
		k) sort_field="${OPTARG%%,*}" ;; # only up to first comma
			# NB: Unlike sort(1) only one POS allowed
		t) sort_sep="$OPTARG"
		   if [ ${#sort_sep} -gt 1 ]; then
		   	echo "$funcname: multi-character tab \`$sort_sep'" >&2
		   	return 1
		   fi
		   sort_strict_fields=1
		   ;;
		\?) return 1 ;;
		esac
	done
	shift $(( $OPTIND - 1 ))

	# Create transformation pattern to trim leading text if desired
	case "$sort_field" in
	""|[!0-9]*|*[!0-9.]*)
		echo "$funcname: invalid sort field \`$sort_field'" >&2
		return 1
		;;
	*.*)
		skip_leading=${sort_field#*.} sort_field=${sort_field%%.*}
		while [ ${skip_leading:-0} -gt 1 ] 2> /dev/null; do
			trim="$trim?" skip_leading=$(( $skip_leading - 1 ))
		done
	esac

	# Copy input to series of local numbered variables
	# NB: IFS of NULL preserves leading whitespace
	local LINE
	while IFS= read -r LINE || [ "$LINE" ]; do
		nitems=$(( $nitems + 1 ))
		local src_$nitems="$LINE"
	done

	#
	# Sort numbered locals using insertion sort
	#
	local curitem curitem_orig curitem_mod curitem_haskey
	local dest dest_orig dest_mod dest_haskey
	local d gt n
	local i=1 
	while [ $i -le $nitems ]; do
		curitem_haskey=1 # Assume sort field (-k POS) exists
		eval curitem=\"\$src_$i\"
		curitem_mod="$curitem" # for modified comparison
		curitem_orig="$curitem" # for original comparison

		# Trim leading whitespace if desired
		if [ "$sort_ignore_leading_space" ]; then
			while case "$curitem_orig" in
				[$IFS]*) : ;; *) false; esac
			do
				curitem_orig="${curitem_orig#?}"
			done
			curitem_mod="$curitem_orig"
		fi

		# Shift modified comparison value if sort field (-k POS) is > 1
		n=$sort_field
		while [ $n -gt 1 ]; do
			case "$curitem_mod" in
			*[$sort_sep]*)
				# Cut text up-to (and incl.) first separator
				curitem_mod="${curitem_mod#*[$sort_sep]}"

				# Skip NULLs unless strict field splitting
				[ "$sort_strict_fields" ] ||
					[ "${curitem_mod%%[$sort_sep]*}" ] ||
					[ $n -eq 2 ] ||
					continue
				;;
			*)
				# Asked for a field that doesn't exist
				curitem_haskey= break
			esac
			n=$(( $n - 1 ))
		done

		# Trim trailing words if sort field >= 1
		[ $sort_field -ge 1 -a "$sort_numeric" ] &&
			curitem_mod="${curitem_mod%%[$sort_sep]*}"

		# Apply optional trim (-k POS.TRIM) to cut leading characters
		curitem_mod="${curitem_mod#$trim}"

		# Determine the type of modified comparison to use initially
		# NB: Prefer numerical if requested but fallback to standard
		case "$curitem_mod" in
		""|[!0-9]*) # NULL or begins with non-number
			gt=">"
			[ "$sort_numeric" ] && curitem_mod=0
			;;
		*)
			if [ "$sort_numeric" ]; then
				gt="-gt"
				curitem_mod="${curitem_mod%%[!0-9]*}"
					# NB: trailing non-digits removed
					# otherwise numeric comparison fails
			else
				gt=">"
			fi
		esac

		# If first time through, short-circuit below position-search
		if [ $i -le 1 ]; then
			d=0
		else
			d=1
		fi

		#
		# Find appropriate element position
		#
		while [ $d -gt 0 ]
		do
			dest_haskey=$curitem_haskey
			eval dest=\"\$dest_$d\"
			dest_mod="$dest" # for modified comparison
			dest_orig="$dest" # for original comparison

			# Trim leading whitespace if desired
			if [ "$sort_ignore_leading_space" ]; then
				while case "$dest_orig" in
					[$IFS]*) : ;; *) false; esac
				do
					dest_orig="${dest_orig#?}"
				done
				dest_mod="$dest_orig"
			fi

			# Shift modified value if sort field (-k POS) is > 1
			n=$sort_field
			while [ $n -gt 1 ]; do
				case "$dest_mod" in
				*[$sort_sep]*)
					# Cut text up-to (and incl.) 1st sep
					dest_mod="${dest_mod#*[$sort_sep]}"

					# Skip NULLs unless strict fields
					[ "$sort_strict_fields" ] ||
					    [ "${dest_mod%%[$sort_sep]*}" ] ||
					    [ $n -eq 2 ] ||
					    continue
					;;
				*)
					# Asked for a field that doesn't exist
					dest_haskey= break
				esac
				n=$(( $n - 1 ))
			done

			# Trim trailing words if sort field >= 1
			[ $sort_field -ge 1 -a "$sort_numeric" ] &&
				dest_mod="${dest_mod%%[$sort_sep]*}"

			# Apply optional trim (-k POS.TRIM), cut leading chars
			dest_mod="${dest_mod#$trim}"

			# Determine type of modified comparison to use
			# NB: Prefer numerical if requested, fallback to std
			case "$dest_mod" in
			""|[!0-9]*) # NULL or begins with non-number
				gt=">"
				[ "$sort_numeric" ] && dest_mod=0
				;;
			*)
				if [ "$sort_numeric" ]; then
					gt="-gt"
					dest_mod="${dest_mod%%[!0-9]*}"
						# NB: kill trailing non-digits
						# for numeric comparison safety
				else
					gt=">"
				fi
			esac

			# Break if we've found the proper element position
			if [ "$curitem_haskey" -a "$dest_haskey" ]; then
				if [ "$dest_mod" = "$curitem_mod" ]; then
					[ "$dest_orig" ">" "$curitem_orig" ] &&
						break
				elif [ "$dest_mod" $gt "$curitem_mod" ] \
					2> /dev/null
				then
					break
				fi
			else
				[ "$dest_orig" ">" "$curitem_orig" ] && break
			fi

			# Break if we've hit the end
			[ $d -ge $i ] && break

			d=$(( $d + 1 ))
		done

		# Shift remaining positions forward, making room for new item
		n=$i
		while [ $n -ge $d ]; do
			# Shift destination item forward one placement
			eval dest_$(( $n + 1 ))=\"\$dest_$n\"
			n=$(( $n - 1 ))
		done

		# Place the element
		if [ $i -eq 1 ]; then
			local dest_1="$curitem"
		else
			local dest_$d="$curitem"
		fi

		i=$(( $i + 1 ))
	done

	# Print sorted results
	d=1
	while [ $d -le $nitems ]; do
		eval echo \"\$dest_$d\"
		d=$(( $d + 1 ))
	done
}

#
# wait_for_pids pid [pid ...]
#	spins until none of the pids exist
#
wait_for_pids()
{
	local _list _prefix _nlist _j

	_list="$@"
	if [ -z "$_list" ]; then
		return
	fi
	_prefix=
	while true; do
		_nlist="";
		for _j in $_list; do
			if kill -0 $_j 2>/dev/null; then
				_nlist="${_nlist}${_nlist:+ }$_j"
				[ -n "$_prefix" ] && sleep 1
			fi
		done
		if [ -z "$_nlist" ]; then
			break
		fi
		_list=$_nlist
		echo -n ${_prefix:-"Waiting for PIDS: "}$_list
		_prefix=", "
		pwait $_list 2>/dev/null
	done
	if [ -n "$_prefix" ]; then
		echo "."
	fi
}

#
# get_pidfile_from_conf string file
#
#	Takes a string to search for in the specified file.
#	Ignores lines with traditional comment characters.
#
# Example:
#
# if get_pidfile_from_conf string file; then
#	pidfile="$_pidfile_from_conf"
# else
#	pidfile='appropriate default'
# fi
#
get_pidfile_from_conf()
{
	if [ -z "$1" -o -z "$2" ]; then
		err 3 "USAGE: get_pidfile_from_conf string file ($name)"
	fi

	local string file line

	string="$1" ; file="$2"

	if [ ! -s "$file" ]; then
		err 3 "get_pidfile_from_conf: $file does not exist ($name)"
	fi

	while read line; do
		case "$line" in
		*[#\;]*${string}*)	continue ;;
		*${string}*)		break ;;
		esac
	done < $file

	if [ -n "$line" ]; then
		line=${line#*/}
		_pidfile_from_conf="/${line%%[\"\;]*}"
	else
		return 1
	fi
}

#
# check_startmsgs
#	If rc_quiet is set (usually as a result of using faststart at
#	boot time) check if rc_startmsgs is enabled.
#
check_startmsgs()
{
	if [ -n "$rc_quiet" ]; then
		checkyesno rc_startmsgs
	else
		return 0
	fi
}

#
# run_rc_command argument
#	Search for argument in the list of supported commands, which is:
#		"start stop restart rcvar status poll ${extra_commands}"
#	If there's a match, run ${argument}_cmd or the default method
#	(see below).
#
#	If argument has a given prefix, then change the operation as follows:
#		Prefix	Operation
#		------	---------
#		fast	Skip the pid check, and set rc_fast=yes, rc_quiet=yes
#		force	Set ${rcvar} to YES, and set rc_force=yes
#		one	Set ${rcvar} to YES
#		quiet	Don't output some diagnostics, and set rc_quiet=yes
#
#	The following globals are used:
#
#	Name		Needed	Purpose
#	----		------	-------
#	name		y	Name of script.
#
#	command		n	Full path to command.
#				Not needed if ${rc_arg}_cmd is set for
#				each keyword.
#
#	command_args	n	Optional args/shell directives for command.
#
#	command_interpreter n	If not empty, command is interpreted, so
#				call check_{pidfile,process}() appropriately.
#
#	desc		n	Description of script.
#
#	extra_commands	n	List of extra commands supported.
#
#	pidfile		n	If set, use check_pidfile $pidfile $command,
#				otherwise use check_process $command.
#				In either case, only check if $command is set.
#
#	procname	n	Process name to check for instead of $command.
#
#	rcvar		n	This is checked with checkyesno to determine
#				if the action should be run.
#
#	${name}_program	n	Full path to command.
#				Meant to be used in /etc/rc.conf to override
#				${command}.
#
#	${name}_chroot	n	Directory to chroot to before running ${command}
#				Requires /usr to be mounted.
#
#	${name}_chdir	n	Directory to cd to before running ${command}
#				(if not using ${name}_chroot).
#
#	${name}_flags	n	Arguments to call ${command} with.
#				NOTE:	$flags from the parent environment
#					can be used to override this.
#
#	${name}_fib	n	Routing table number to run ${command} with.
#
#	${name}_nice	n	Nice level to run ${command} at.
#
#	${name}_user	n	User to run ${command} as, using su(1) if not
#				using ${name}_chroot.
#				Requires /usr to be mounted.
#
#	${name}_group	n	Group to run chrooted ${command} as.
#				Requires /usr to be mounted.
#
#	${name}_groups	n	Comma separated list of supplementary groups
#				to run the chrooted ${command} with.
#				Requires /usr to be mounted.
#
#	${rc_arg}_cmd	n	If set, use this as the method when invoked;
#				Otherwise, use default command (see below)
#
#	${rc_arg}_precmd n	If set, run just before performing the
#				${rc_arg}_cmd method in the default
#				operation (i.e, after checking for required
#				bits and process (non)existence).
#				If this completes with a non-zero exit code,
#				don't run ${rc_arg}_cmd.
#
#	${rc_arg}_postcmd n	If set, run just after performing the
#				${rc_arg}_cmd method, if that method
#				returned a zero exit code.
#
#	required_dirs	n	If set, check for the existence of the given
#				directories before running a (re)start command.
#
#	required_files	n	If set, check for the readability of the given
#				files before running a (re)start command.
#
#	required_modules n	If set, ensure the given kernel modules are
#				loaded before running a (re)start command.
#				The check and possible loads are actually
#				done after start_precmd so that the modules
#				aren't loaded in vain, should the precmd
#				return a non-zero status to indicate a error.
#				If a word in the list looks like "foo:bar",
#				"foo" is the KLD file name and "bar" is the
#				module name.  If a word looks like "foo~bar",
#				"foo" is the KLD file name and "bar" is a
#				egrep(1) pattern matching the module name.
#				Otherwise the module name is assumed to be
#				the same as the KLD file name, which is most
#				common.  See load_kld().
#
#	required_vars	n	If set, perform checkyesno on each of the
#				listed variables before running the default
#				(re)start command.
#
#	Default behaviour for a given argument, if no override method is
#	provided:
#
#	Argument	Default behaviour
#	--------	-----------------
#	start		if !running && checkyesno ${rcvar}
#				${command}
#
#	stop		if ${pidfile}
#				rc_pid=$(check_pidfile $pidfile $command)
#			else
#				rc_pid=$(check_process $command)
#			kill $sig_stop $rc_pid
#			wait_for_pids $rc_pid
#			($sig_stop defaults to TERM.)
#
#	reload		Similar to stop, except use $sig_reload instead,
#			and doesn't wait_for_pids.
#			$sig_reload defaults to HUP.
#			Note that `reload' isn't provided by default,
#			it should be enabled via $extra_commands.
#
#	restart		Run `stop' then `start'.
#
#	status		Show if ${command} is running, etc.
#
#	poll		Wait for ${command} to exit.
#
#	rcvar		Display what rc.conf variable is used (if any).
#
#	enabled		Return true if the service is enabled.
#
#	Variables available to methods, and after run_rc_command() has
#	completed:
#
#	Variable	Purpose
#	--------	-------
#	rc_arg		Argument to command, after fast/force/one processing
#			performed
#
#	rc_flags	Flags to start the default command with.
#			Defaults to ${name}_flags, unless overridden
#			by $flags from the environment.
#			This variable may be changed by the precmd method.
#
#	rc_pid		PID of command (if appropriate)
#
#	rc_fast		Not empty if "fast" was provided (q.v.)
#
#	rc_force	Not empty if "force" was provided (q.v.)
#
#	rc_quiet	Not empty if "quiet" was provided
#
#
run_rc_command()
{
	_return=0
	rc_arg=$1
	if [ -z "$name" ]; then
		err 3 'run_rc_command: $name is not set.'
	fi

	# Don't repeat the first argument when passing additional command-
	# line arguments to the command subroutines.
	#
	shift 1
	rc_extra_args="$*"

	_rc_prefix=
	case "$rc_arg" in
	fast*)				# "fast" prefix; don't check pid
		rc_arg=${rc_arg#fast}
		rc_fast=yes
		rc_quiet=yes
		;;
	force*)				# "force" prefix; always run
		rc_force=yes
		_rc_prefix=force
		rc_arg=${rc_arg#${_rc_prefix}}
		if [ -n "${rcvar}" ]; then
			eval ${rcvar}=YES
		fi
		;;
	one*)				# "one" prefix; set ${rcvar}=yes
		_rc_prefix=one
		rc_arg=${rc_arg#${_rc_prefix}}
		if [ -n "${rcvar}" ]; then
			eval ${rcvar}=YES
		fi
		;;
	quiet*)				# "quiet" prefix; omit some messages
		_rc_prefix=quiet
		rc_arg=${rc_arg#${_rc_prefix}}
		rc_quiet=yes
		;;
	esac

	eval _override_command=\$${name}_program
	command=${_override_command:-$command}

	_keywords="start stop restart rcvar enabled $extra_commands"
	rc_pid=
	_pidcmd=
	_procname=${procname:-${command}}

					# setup pid check command
	if [ -n "$_procname" ]; then
		if [ -n "$pidfile" ]; then
			_pidcmd='rc_pid=$(check_pidfile '"$pidfile $_procname $command_interpreter"')'
		else
			_pidcmd='rc_pid=$(check_process '"$_procname $command_interpreter"')'
		fi
		if [ -n "$_pidcmd" ]; then
			_keywords="${_keywords} status poll"
		fi
	fi

	if [ -z "$rc_arg" ]; then
		rc_usage $_keywords
	fi

	if [ "$rc_arg" = "enabled" ] ; then
		checkyesno ${rcvar}
		return $?
	fi

	if [ -n "$flags" ]; then	# allow override from environment
		rc_flags=$flags
	else
		eval rc_flags=\$${name}_flags
	fi
	eval _chdir=\$${name}_chdir	_chroot=\$${name}_chroot \
	    _nice=\$${name}_nice	_user=\$${name}_user \
	    _group=\$${name}_group	_groups=\$${name}_groups \
	    _fib=\$${name}_fib

	if [ -n "$_user" ]; then	# unset $_user if running as that user
		if [ "$_user" = "$(eval $IDCMD)" ]; then
			unset _user
		fi
	fi

	[ -z "$autoboot" ] && eval $_pidcmd	# determine the pid if necessary

	for _elem in $_keywords; do
		if [ "$_elem" != "$rc_arg" ]; then
			continue
		fi
					# if ${rcvar} is set, $1 is not "rcvar"
					# and ${rc_pid} is not set, then run
					#	checkyesno ${rcvar}
					# and return if that failed
					#
		if [ -n "${rcvar}" -a "$rc_arg" != "rcvar" -a "$rc_arg" != "stop" ] ||
		    [ -n "${rcvar}" -a "$rc_arg" = "stop" -a -z "${rc_pid}" ]; then
			if ! checkyesno ${rcvar}; then
				if [ -n "${rc_quiet}" ]; then
					return 0
				fi
				echo -n "Cannot '${rc_arg}' $name. Set ${rcvar} to "
				echo -n "YES in /etc/rc.conf or use 'one${rc_arg}' "
				echo "instead of '${rc_arg}'."
				return 0
			fi
		fi

					# if there's a custom ${XXX_cmd},
					# run that instead of the default
					#
		eval _cmd=\$${rc_arg}_cmd \
		     _precmd=\$${rc_arg}_precmd \
		     _postcmd=\$${rc_arg}_postcmd

		if [ -n "$_cmd" ]; then
			_run_rc_precmd || return 1
			_run_rc_doit "$_cmd $rc_extra_args" || return 1
			_run_rc_postcmd
			return $_return
		fi

		case "$rc_arg" in	# default operations...

		status)
			_run_rc_precmd || return 1
			if [ -n "$rc_pid" ]; then
				echo "${name} is running as pid $rc_pid."
			else
				echo "${name} is not running."
				return 1
			fi
			_run_rc_postcmd
			;;

		start)
			if [ -z "$rc_fast" -a -n "$rc_pid" ]; then
				if [ -z "$rc_quiet" ]; then
					echo 1>&2 "${name} already running? " \
					    "(pid=$rc_pid)."
				fi
				return 1
			fi

			if [ ! -x "${_chroot}${_chroot:+/}${command}" ]; then
				warn "run_rc_command: cannot run $command"
				return 1
			fi

			if ! _run_rc_precmd; then
				warn "failed precmd routine for ${name}"
				return 1
			fi

					# setup the full command to run
					#
			check_startmsgs && echo "Starting ${name}."
			if [ -n "$_chroot" ]; then
				_doit="\
${_nice:+nice -n $_nice }\
${_fib:+setfib -F $_fib }\
chroot ${_user:+-u $_user }${_group:+-g $_group }${_groups:+-G $_groups }\
$_chroot $command $rc_flags $command_args"
			else
				_doit="\
${_chdir:+cd $_chdir && }\
${_fib:+setfib -F $_fib }\
$command $rc_flags $command_args"
				if [ -n "$_user" ]; then
				    _doit="su -m $_user -c 'sh -c \"$_doit\"'"
				fi
				if [ -n "$_nice" ]; then
					if [ -z "$_user" ]; then
						_doit="sh -c \"$_doit\""
					fi
					_doit="nice -n $_nice $_doit"
				fi
			fi

					# run the full command
					#
			if ! _run_rc_doit "$_doit"; then
				warn "failed to start ${name}"
				return 1
			fi

					# finally, run postcmd
					#
			_run_rc_postcmd
			;;

		stop)
			if [ -z "$rc_pid" ]; then
				[ -n "$rc_fast" ] && return 0
				_run_rc_notrunning
				return 1
			fi

			_run_rc_precmd || return 1

					# send the signal to stop
					#
			echo "Stopping ${name}."
			_doit=$(_run_rc_killcmd "${sig_stop:-TERM}")
			_run_rc_doit "$_doit" || return 1

					# wait for the command to exit,
					# and run postcmd.
			wait_for_pids $rc_pid

			_run_rc_postcmd
			;;

		reload)
			if [ -z "$rc_pid" ]; then
				_run_rc_notrunning
				return 1
			fi

			_run_rc_precmd || return 1

			_doit=$(_run_rc_killcmd "${sig_reload:-HUP}")
			_run_rc_doit "$_doit" || return 1

			_run_rc_postcmd
			;;

		restart)
					# prevent restart being called more
					# than once by any given script
					#
			if ${_rc_restart_done:-false}; then
				return 0
			fi
			_rc_restart_done=true

			_run_rc_precmd || return 1

			# run those in a subshell to keep global variables
			( run_rc_command ${_rc_prefix}stop $rc_extra_args )
			( run_rc_command ${_rc_prefix}start $rc_extra_args )
			_return=$?
			[ $_return -ne 0 ] && [ -z "$rc_force" ] && return 1

			_run_rc_postcmd
			;;

		poll)
			_run_rc_precmd || return 1
			if [ -n "$rc_pid" ]; then
				wait_for_pids $rc_pid
			fi
			_run_rc_postcmd
			;;

		rcvar)
			echo -n "# $name"
			if [ -n "$desc" ]; then
				echo " : $desc"
			else
				echo ""
			fi
			echo "#"
			# Get unique vars in $rcvar
			for _v in $rcvar; do
				case $v in
				$_v\ *|\ *$_v|*\ $_v\ *) ;;
				*)	v="${v# } $_v" ;;
				esac
			done

			# Display variables.
			for _v in $v; do
				if [ -z "$_v" ]; then
					continue
				fi

				eval _desc=\$${_v}_desc
				eval _defval=\$${_v}_defval
				_h="-"

				eval echo \"$_v=\\\"\$$_v\\\"\"
				# decode multiple lines of _desc
				while [ -n "$_desc" ]; do
					case $_desc in
					*^^*)
						echo "# $_h ${_desc%%^^*}"
						_desc=${_desc#*^^}
						_h=" "
						;;
					*)
						echo "# $_h ${_desc}"
						break
						;;
					esac
				done
				echo "#   (default: \"$_defval\")"
			done
			echo ""
			;;

		*)
			rc_usage $_keywords
			;;

		esac
		return $_return
	done

	echo 1>&2 "$0: unknown directive '$rc_arg'."
	rc_usage $_keywords
	# not reached
}

#
# Helper functions for run_rc_command: common code.
# They use such global variables besides the exported rc_* ones:
#
#	name	       R/W
#	------------------
#	_precmd		R
#	_postcmd	R
#	_return		W
#
_run_rc_precmd()
{
	check_required_before "$rc_arg" || return 1

	if [ -n "$_precmd" ]; then
		debug "run_rc_command: ${rc_arg}_precmd: $_precmd $rc_extra_args"
		eval "$_precmd $rc_extra_args"
		_return=$?

		# If precmd failed and force isn't set, request exit.
		if [ $_return -ne 0 ] && [ -z "$rc_force" ]; then
			return 1
		fi
	fi

	check_required_after "$rc_arg" || return 1

	return 0
}

_run_rc_postcmd()
{
	if [ -n "$_postcmd" ]; then
		debug "run_rc_command: ${rc_arg}_postcmd: $_postcmd $rc_extra_args"
		eval "$_postcmd $rc_extra_args"
		_return=$?
	fi
	return 0
}

_run_rc_doit()
{
	debug "run_rc_command: doit: $*"
	eval "$@"
	_return=$?

	# If command failed and force isn't set, request exit.
	if [ $_return -ne 0 ] && [ -z "$rc_force" ]; then
		return 1
	fi

	return 0
}

_run_rc_notrunning()
{
	local _pidmsg

	if [ -n "$pidfile" ]; then
		_pidmsg=" (check $pidfile)."
	else
		_pidmsg=
	fi
	echo 1>&2 "${name} not running?${_pidmsg}"
}

_run_rc_killcmd()
{
	local _cmd

	_cmd="kill -$1 $rc_pid"
	if [ -n "$_user" ]; then
		_cmd="su -m ${_user} -c 'sh -c \"${_cmd}\"'"
	fi
	echo "$_cmd"
}

#
# run_rc_script file arg
#	Start the script `file' with `arg', and correctly handle the
#	return value from the script.
#	If `file' ends with `.sh', it's sourced into the current environment
#	when $rc_fast_and_loose is set, otherwise it is run as a child process.
#	If `file' appears to be a backup or scratch file, ignore it.
#	Otherwise if it is executable run as a child process.
#
run_rc_script()
{
	_file=$1
	_arg=$2
	if [ -z "$_file" -o -z "$_arg" ]; then
		err 3 'USAGE: run_rc_script file arg'
	fi

	unset	name command command_args command_interpreter \
		extra_commands pidfile procname \
		rcvar rcvars_obsolete required_dirs required_files \
		required_vars
	eval unset ${_arg}_cmd ${_arg}_precmd ${_arg}_postcmd

	case "$_file" in
	/etc/rc.d/*.sh)			# no longer allowed in the base
		warn "Ignoring old-style startup script $_file"
		;;
	*[~#]|*.OLD|*.bak|*.orig|*,v)	# scratch file; skip
		warn "Ignoring scratch file $_file"
		;;
	*)				# run in subshell
		if [ -x $_file ]; then
			if [ -n "$rc_fast_and_loose" ]; then
				set $_arg; . $_file
			else
				( trap "echo Script $_file interrupted >&2 ; kill -QUIT $$" 3
				  trap "echo Script $_file interrupted >&2 ; exit 1" 2
				  trap "echo Script $_file running >&2" 29
				  set $_arg; . $_file )
			fi
		fi
		;;
	esac
}

#
# load_rc_config name
#	Source in the configuration file for a given name.
#
load_rc_config()
{
	local _name _rcvar_val _var _defval _v _msg _new
	_name=$1
	if [ -z "$_name" ]; then
		err 3 'USAGE: load_rc_config name'
	fi

	if ${_rc_conf_loaded:-false}; then
		:
	else
		if [ -r /etc/defaults/rc.conf ]; then
			debug "Sourcing /etc/defaults/rc.conf"
			. /etc/defaults/rc.conf
			source_rc_confs
		elif [ -r /etc/rc.conf ]; then
			debug "Sourcing /etc/rc.conf (/etc/defaults/rc.conf doesn't exist)."
			. /etc/rc.conf
		fi
		_rc_conf_loaded=true
	fi
	if [ -f /etc/rc.conf.d/"$_name" ]; then
		debug "Sourcing /etc/rc.conf.d/${_name}"
		. /etc/rc.conf.d/"$_name"
	fi

	# Set defaults if defined.
	for _var in $rcvar; do
		eval _defval=\$${_var}_defval
		if [ -n "$_defval" ]; then
			eval : \${$_var:=\$${_var}_defval}
		fi
	done

	# check obsolete rc.conf variables
	for _var in $rcvars_obsolete; do
		eval _v=\$$_var
		eval _msg=\$${_var}_obsolete_msg
		eval _new=\$${_var}_newvar
		case $_v in
		"")
			;;
		*)
			if [ -z "$_new" ]; then
				_msg="Ignored."
			else
				eval $_new=\"\$$_var\"
				if [ -z "$_msg" ]; then
					_msg="Use \$$_new instead."
				fi
			fi
			warn "\$$_var is obsolete.  $_msg"
			;;
		esac
	done
}

#
# load_rc_config_var name var
#	Read the rc.conf(5) var for name and set in the
#	current shell, using load_rc_config in a subshell to prevent
#	unwanted side effects from other variable assignments.
#
load_rc_config_var()
{
	if [ $# -ne 2 ]; then
		err 3 'USAGE: load_rc_config_var name var'
	fi
	eval $(eval '(
		load_rc_config '$1' >/dev/null;
                if [ -n "${'$2'}" -o "${'$2'-UNSET}" != "UNSET" ]; then
			echo '$2'=\'\''${'$2'}\'\'';
		fi
	)' )
}

#
# rc_usage commands
#	Print a usage string for $0, with `commands' being a list of
#	valid commands.
#
rc_usage()
{
	echo -n 1>&2 "Usage: $0 [fast|force|one|quiet]("

	_sep=
	for _elem; do
		echo -n 1>&2 "$_sep$_elem"
		_sep="|"
	done
	echo 1>&2 ")"
	exit 1
}

#
# err exitval message
#	Display message to stderr and log to the syslog, and exit with exitval.
#
err()
{
	exitval=$1
	shift

	if [ -x /usr/bin/logger ]; then
		logger "$0: ERROR: $*"
	fi
	echo 1>&2 "$0: ERROR: $*"
	exit $exitval
}

#
# warn message
#	Display message to stderr and log to the syslog.
#
warn()
{
	if [ -x /usr/bin/logger ]; then
		logger "$0: WARNING: $*"
	fi
	echo 1>&2 "$0: WARNING: $*"
}

#
# info message
#	Display informational message to stdout and log to syslog.
#
info()
{
	case ${rc_info} in
	[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
		if [ -x /usr/bin/logger ]; then
			logger "$0: INFO: $*"
		fi
		echo "$0: INFO: $*"
		;;
	esac
}

#
# debug message
#	If debugging is enabled in rc.conf output message to stderr.
#	BEWARE that you don't call any subroutine that itself calls this
#	function.
#
debug()
{
	case ${rc_debug} in
	[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
		if [ -x /usr/bin/logger ]; then
			logger "$0: DEBUG: $*"
		fi
		echo 1>&2 "$0: DEBUG: $*"
		;;
	esac
}

#
# backup_file action file cur backup
#	Make a backup copy of `file' into `cur', and save the previous
#	version of `cur' as `backup' or use rcs for archiving.
#
#	This routine checks the value of the backup_uses_rcs variable,
#	which can be either YES or NO.
#
#	The `action' keyword can be one of the following:
#
#	add		`file' is now being backed up (and is possibly
#			being reentered into the backups system).  `cur'
#			is created and RCS files, if necessary, are
#			created as well.
#
#	update		`file' has changed and needs to be backed up.
#			If `cur' exists, it is copied to to `back' or
#			checked into RCS (if the repository file is old),
#			and then `file' is copied to `cur'.  Another RCS
#			check in done here if RCS is being used.
#
#	remove		`file' is no longer being tracked by the backups
#			system.  If RCS is not being used, `cur' is moved
#			to `back', otherwise an empty file is checked in,
#			and then `cur' is removed.
#
#
backup_file()
{
	_action=$1
	_file=$2
	_cur=$3
	_back=$4

	if checkyesno backup_uses_rcs; then
		_msg0="backup archive"
		_msg1="update"

		# ensure that history file is not locked
		if [ -f $_cur,v ]; then
			rcs -q -u -U -M $_cur
		fi

		# ensure after switching to rcs that the
		# current backup is not lost
		if [ -f $_cur ]; then
			# no archive, or current newer than archive
			if [ ! -f $_cur,v -o $_cur -nt $_cur,v ]; then
				ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
				rcs -q -kb -U $_cur
				co -q -f -u $_cur
			fi
		fi

		case $_action in
		add|update)
			cp -p $_file $_cur
			ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
			rcs -q -kb -U $_cur
			co -q -f -u $_cur
			chown root:wheel $_cur $_cur,v
			;;
		remove)
			cp /dev/null $_cur
			ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
			rcs -q -kb -U $_cur
			chown root:wheel $_cur $_cur,v
			rm $_cur
			;;
		esac
	else
		case $_action in
		add|update)
			if [ -f $_cur ]; then
				cp -p $_cur $_back
			fi
			cp -p $_file $_cur
			chown root:wheel $_cur
			;;
		remove)
			mv -f $_cur $_back
			;;
		esac
	fi
}

# make_symlink src link
#	Make a symbolic link 'link' to src from basedir. If the
#	directory in which link is to be created does not exist
#	a warning will be displayed and an error will be returned.
#	Returns 0 on success, 1 otherwise.
#
make_symlink()
{
	local src link linkdir _me
	src="$1"
	link="$2"
	linkdir="`dirname $link`"
	_me="make_symlink()"

	if [ -z "$src" -o -z "$link" ]; then
		warn "$_me: requires two arguments."
		return 1
	fi
	if [ ! -d "$linkdir" ]; then
		warn "$_me: the directory $linkdir does not exist."
		return 1
	fi
	if ! ln -sf $src $link; then
		warn "$_me: unable to make a symbolic link from $link to $src"
		return 1
	fi
	return 0
}

# devfs_rulesets_from_file file
#	Reads a set of devfs commands from file, and creates
#	the specified rulesets with their rules. Returns non-zero
#	if there was an error.
#
devfs_rulesets_from_file()
{
	local file _err _me _opts
	file="$1"
	_me="devfs_rulesets_from_file"
	_err=0

	if [ -z "$file" ]; then
		warn "$_me: you must specify a file"
		return 1
	fi
	if [ ! -e "$file" ]; then
		debug "$_me: no such file ($file)"
		return 0
	fi

	# Disable globbing so that the rule patterns are not expanded
	# by accident with matching filesystem entries.
	_opts=$-; set -f

	debug "reading rulesets from file ($file)"
	{ while read line
	do
		case $line in
		\#*)
			continue
			;;
		\[*\]*)
			rulenum=`expr "$line" : "\[.*=\([0-9]*\)\]"`
			if [ -z "$rulenum" ]; then
				warn "$_me: cannot extract rule number ($line)"
				_err=1
				break
			fi
			rulename=`expr "$line" : "\[\(.*\)=[0-9]*\]"`
			if [ -z "$rulename" ]; then
				warn "$_me: cannot extract rule name ($line)"
				_err=1
				break;
			fi
			eval $rulename=\$rulenum
			debug "found ruleset: $rulename=$rulenum"
			if ! /sbin/devfs rule -s $rulenum delset; then
				_err=1
				break
			fi
			;;
		*)
			rulecmd="${line%%"\#*"}"
			# evaluate the command incase it includes
			# other rules
			if [ -n "$rulecmd" ]; then
				debug "adding rule ($rulecmd)"
				if ! eval /sbin/devfs rule -s $rulenum $rulecmd
				then
					_err=1
					break
				fi
			fi
			;;
		esac
		if [ $_err -ne 0 ]; then
			debug "error in $_me"
			break
		fi
	done } < $file
	case $_opts in *f*) ;; *) set +f ;; esac
	return $_err
}

# devfs_init_rulesets
#	Initializes rulesets from configuration files. Returns
#	non-zero if there was an error.
#
devfs_init_rulesets()
{
	local file _me
	_me="devfs_init_rulesets"

	# Go through this only once
	if [ -n "$devfs_rulesets_init" ]; then
		debug "$_me: devfs rulesets already initialized"
		return
	fi
	for file in $devfs_rulesets; do
		if ! devfs_rulesets_from_file $file; then
			warn "$_me: could not read rules from $file"
			return 1
		fi
	done
	devfs_rulesets_init=1
	debug "$_me: devfs rulesets initialized"
	return 0
}

# devfs_set_ruleset ruleset [dir]
#	Sets the default ruleset of dir to ruleset. The ruleset argument
#	must be a ruleset name as specified in devfs.rules(5) file.
#	Returns non-zero if it could not set it successfully.
#
devfs_set_ruleset()
{
	local devdir rs _me
	[ -n "$1" ] && eval rs=\$$1 || rs=
	[ -n "$2" ] && devdir="-m "$2"" || devdir=
	_me="devfs_set_ruleset"

	if [ -z "$rs" ]; then
		warn "$_me: you must specify a ruleset number"
		return 1
	fi
	debug "$_me: setting ruleset ($rs) on mount-point (${devdir#-m })"
	if ! /sbin/devfs $devdir ruleset $rs; then
		warn "$_me: unable to set ruleset $rs to ${devdir#-m }"
		return 1
	fi
	return 0
}

# devfs_apply_ruleset ruleset [dir]
#	Apply ruleset number $ruleset to the devfs mountpoint $dir.
#	The ruleset argument must be a ruleset name as specified
#	in a devfs.rules(5) file.  Returns 0 on success or non-zero
#	if it could not apply the ruleset.
#
devfs_apply_ruleset()
{
	local devdir rs _me
	[ -n "$1" ] && eval rs=\$$1 || rs=
	[ -n "$2" ] && devdir="-m "$2"" || devdir=
	_me="devfs_apply_ruleset"

	if [ -z "$rs" ]; then
		warn "$_me: you must specify a ruleset"
		return 1
	fi
	debug "$_me: applying ruleset ($rs) to mount-point (${devdir#-m })"
	if ! /sbin/devfs $devdir rule -s $rs applyset; then
		warn "$_me: unable to apply ruleset $rs to ${devdir#-m }"
		return 1
	fi
	return 0
}

# devfs_domount dir [ruleset]
#	Mount devfs on dir. If ruleset is specified it is set
#	on the mount-point. It must also be a ruleset name as specified
#	in a devfs.rules(5) file. Returns 0 on success.
#
devfs_domount()
{
	local devdir rs _me
	devdir="$1"
	[ -n "$2" ] && rs=$2 || rs=
	_me="devfs_domount()"

	if [ -z "$devdir" ]; then
		warn "$_me: you must specify a mount-point"
		return 1
	fi
	debug "$_me: mount-point is ($devdir), ruleset is ($rs)"
	if ! mount -t devfs dev "$devdir"; then
		warn "$_me: Unable to mount devfs on $devdir"
		return 1
	fi
	if [ -n "$rs" ]; then
		devfs_init_rulesets
		devfs_set_ruleset $rs $devdir
		devfs -m $devdir rule applyset
	fi
	return 0
}

# Provide a function for normalizing the mounting of memory
# filesystems.  This should allow the rest of the code here to remain
# as close as possible between 5-current and 4-stable.
#   $1 = size
#   $2 = mount point
#   $3 = (optional) extra mdmfs flags
mount_md()
{
	if [ -n "$3" ]; then
		flags="$3"
	fi
	/sbin/mdmfs $flags -s $1 md $2
}

# Code common to scripts that need to load a kernel module
# if it isn't in the kernel yet. Syntax:
#   load_kld [-e regex] [-m module] file
# where -e or -m chooses the way to check if the module
# is already loaded:
#   regex is egrep'd in the output from `kldstat -v',
#   module is passed to `kldstat -m'.
# The default way is as though `-m file' were specified.
load_kld()
{
	local _loaded _mod _opt _re

	while getopts "e:m:" _opt; do
		case "$_opt" in
		e) _re="$OPTARG" ;;
		m) _mod="$OPTARG" ;;
		*) err 3 'USAGE: load_kld [-e regex] [-m module] file' ;;
		esac
	done
	shift $(($OPTIND - 1))
	if [ $# -ne 1 ]; then
		err 3 'USAGE: load_kld [-e regex] [-m module] file'
	fi
	_mod=${_mod:-$1}
	_loaded=false
	if [ -n "$_re" ]; then
		if kldstat -v | egrep -q -e "$_re"; then
			_loaded=true
		fi
	else
		if kldstat -q -m "$_mod"; then
			_loaded=true
		fi
	fi
	if ! $_loaded; then
		if ! kldload "$1"; then
			warn "Unable to load kernel module $1"
			return 1
		else
			info "$1 kernel module loaded."
		fi
	else
		debug "load_kld: $1 kernel module already loaded."
	fi
	return 0
}

# ltr str src dst [var]
#	Change every $src in $str to $dst.
#	Useful when /usr is not yet mounted and we cannot use tr(1), sed(1) nor
#	awk(1). If var is non-NULL, set it to the result.
ltr()
{
	local _str _src _dst _out _com _var
	_str="$1"
	_src="$2"
	_dst="$3"
	_var="$4"
	_out=""

	local IFS="${_src}"
	for _com in ${_str}; do
		if [ -z "${_out}" ]; then
			_out="${_com}"
		else
			_out="${_out}${_dst}${_com}"
		fi
	done
	if [ -n "${_var}" ]; then
		setvar "${_var}" "${_out}"
	else
		echo "${_out}"
	fi
}

# Creates a list of providers for GELI encryption.
geli_make_list()
{
	local devices devices2
	local provider mountpoint type options rest

	# Create list of GELI providers from fstab.
	while read provider mountpoint type options rest ; do
		case ":${options}" in
		:*noauto*)
			noauto=yes
			;;
		*)
			noauto=no
			;;
		esac

		case ":${provider}" in
		:#*)
			continue
			;;
		*.eli)
			# Skip swap devices.
			if [ "${type}" = "swap" -o "${options}" = "sw" -o "${noauto}" = "yes" ]; then
				continue
			fi
			devices="${devices} ${provider}"
			;;
		esac
	done < /etc/fstab

	# Append providers from geli_devices.
	devices="${devices} ${geli_devices}"

	for provider in ${devices}; do
		provider=${provider%.eli}
		provider=${provider#/dev/}
		devices2="${devices2} ${provider}"
	done

	echo ${devices2}
}

# Find scripts in local_startup directories that use the old syntax
#
find_local_scripts_old() {
	zlist=''
	slist=''
	for dir in ${local_startup}; do
		if [ -d "${dir}" ]; then
			for file in ${dir}/[0-9]*.sh; do
				grep '^# PROVIDE:' $file >/dev/null 2>&1 &&
				    continue
				zlist="$zlist $file"
			done
			for file in ${dir}/[!0-9]*.sh; do
				grep '^# PROVIDE:' $file >/dev/null 2>&1 &&
				    continue
				slist="$slist $file"
			done
		fi
	done
}

find_local_scripts_new() {
	local_rc=''
	for dir in ${local_startup}; do
		if [ -d "${dir}" ]; then
			for file in `grep -l '^# PROVIDE:' ${dir}/* 2>/dev/null`; do
				case "$file" in
				*.sample) ;;
				*)	if [ -x "$file" ]; then
						local_rc="${local_rc} ${file}"
					fi
					;;
				esac
			done
		fi
	done
}

# check_required_{before|after} command
#	Check for things required by the command before and after its precmd,
#	respectively.  The two separate functions are needed because some
#	conditions should prevent precmd from being run while other things
#	depend on precmd having already been run.
#
check_required_before()
{
	local _f

	case "$1" in
	start)
		for _f in $required_vars; do
			if ! checkyesno $_f; then
				warn "\$${_f} is not enabled."
				if [ -z "$rc_force" ]; then
					return 1
				fi
			fi
		done

		for _f in $required_dirs; do
			if [ ! -d "${_f}/." ]; then
				warn "${_f} is not a directory."
				if [ -z "$rc_force" ]; then
					return 1
				fi
			fi
		done

		for _f in $required_files; do
			if [ ! -r "${_f}" ]; then
				warn "${_f} is not readable."
				if [ -z "$rc_force" ]; then
					return 1
				fi
			fi
		done
		;;
	esac

	return 0
}

check_required_after()
{
	local _f _args

	case "$1" in
	start)
		for _f in $required_modules; do
			case "${_f}" in
				*~*)	_args="-e ${_f#*~} ${_f%%~*}" ;;
				*:*)	_args="-m ${_f#*:} ${_f%%:*}" ;;
				*)	_args="${_f}" ;;
			esac
			if ! load_kld ${_args}; then
				if [ -z "$rc_force" ]; then
					return 1
				fi
			fi
		done
		;;
	esac

	return 0
}

# check_kern_features mib
#	Return existence of kern.features.* sysctl MIB as true or
#	false.  The result will be cached in $_rc_cache_kern_features_
#	namespace.  "0" means the kern.features.X exists.

check_kern_features()
{
	local _v

	[ -n "$1" ] || return 1;
	eval _v=\$_rc_cache_kern_features_$1
	[ -n "$_v" ] && return "$_v";

	if ${SYSCTL_N} kern.features.$1 > /dev/null 2>&1; then
		eval _rc_cache_kern_features_$1=0
		return 0
	else
		eval _rc_cache_kern_features_$1=1
		return 1
	fi
}

# check_namevarlist var
#	Return "0" if ${name}_var is reserved in rc.subr.

_rc_namevarlist="program chroot chdir flags fib nice user group groups"
check_namevarlist()
{
	local _v

	for _v in $_rc_namevarlist; do
	case $1 in
	$_v)	return 0 ;;
	esac
	done

	return 1
}

# _echoonce var msg mode
#	mode=0: Echo $msg if ${$var} is empty.
#	        After doing echo, a string is set to ${$var}.
#
#	mode=1: Echo $msg if ${$var} is a string with non-zero length.
#
_echoonce()
{
	local _var _msg _mode
	eval _var=\$$1
	_msg=$2
	_mode=$3

	case $_mode in
	1)	[ -n "$_var" ] && echo "$_msg" ;;
	*)	[ -z "$_var" ] && echo -n "$_msg" && eval "$1=finished" ;;
	esac
}

fi # [ -z "${_rc_subr_loaded}" ]

_rc_subr_loaded=: