rc.subr revision 1.58
1# $NetBSD: rc.subr,v 1.58 2003/06/27 05:01:21 lukem Exp $
2#
3# Copyright (c) 1997-2002 The NetBSD Foundation, Inc.
4# All rights reserved.
5#
6# This code is derived from software contributed to The NetBSD Foundation
7# by Luke Mewburn.
8#
9# Redistribution and use in source and binary forms, with or without
10# modification, are permitted provided that the following conditions
11# are met:
12# 1. Redistributions of source code must retain the above copyright
13#    notice, this list of conditions and the following disclaimer.
14# 2. Redistributions in binary form must reproduce the above copyright
15#    notice, this list of conditions and the following disclaimer in the
16#    documentation and/or other materials provided with the distribution.
17# 3. All advertising materials mentioning features or use of this software
18#    must display the following acknowledgement:
19#        This product includes software developed by the NetBSD
20#        Foundation, Inc. and its contributors.
21# 4. Neither the name of The NetBSD Foundation nor the names of its
22#    contributors may be used to endorse or promote products derived
23#    from this software without specific prior written permission.
24#
25# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
29# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35# POSSIBILITY OF SUCH DAMAGE.
36#
37# rc.subr
38#	functions used by various rc scripts
39#
40
41if ${_rc_subr_loaded:-false}; then
42	return
43else
44	_rc_subr_loaded=true
45fi
46
47#
48#	functions
49#	---------
50
51#
52# checkyesno var
53#	Test $1 variable, and warn if not set to YES or NO.
54#	Return 0 if it's "yes" (et al), nonzero otherwise.
55#
56checkyesno()
57{
58	eval _value=\$${1}
59	case $_value in
60
61		#	"yes", "true", "on", or "1"
62	[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
63		return 0
64		;;
65
66		#	"no", "false", "off", or "0"
67	[Nn][Oo]|[Ff][Aa][Ll][Ss][Ee]|[Oo][Ff][Ff]|0)
68		return 1
69		;;
70	*)
71		warn "\$${1} is not set properly - see rc.conf(5)."
72		return 1
73		;;
74	esac
75}
76
77# reverse_list list
78#	print the list in reverse order
79#
80reverse_list()
81{
82	_revlist=
83	for _revfile; do
84		_revlist="$_revfile $_revlist"
85	done
86	echo $_revlist
87}
88
89#
90# mount_critical_filesystems type
91#	Go through the list of critical filesystems as provided in
92#	the rc.conf(5) variable $critical_filesystems_${type}, checking
93#	each one to see if it is mounted, and if it is not, mounting it.
94#
95mount_critical_filesystems()
96{
97	eval _fslist=\$critical_filesystems_${1}
98	for _fs in $_fslist; do
99		mount | (
100			_ismounted=false
101			while read what _on on _type type; do
102				if [ $on = $_fs ]; then
103					_ismounted=true
104				fi
105			done
106			if $_ismounted; then
107				:
108			else
109				mount $_fs >/dev/null 2>&1
110			fi
111		)
112	done
113}
114
115#
116# check_pidfile pidfile procname [interpreter]
117#	Parses the first line of pidfile for a PID, and ensures
118#	that the process is running and matches procname.
119#	Prints the matching PID upon success, nothing otherwise.
120#	interpreter is optional; see _find_processes() for details.
121#
122check_pidfile()
123{
124	_pidfile=$1
125	_procname=$2
126	_interpreter=$3
127	if [ -z "$_pidfile" -o -z "$_procname" ]; then
128		err 3 'USAGE: check_pidfile pidfile procname [interpreter]'
129	fi
130	if [ ! -f $_pidfile ]; then
131		return
132	fi
133	read _pid _junk < $_pidfile
134	if [ -z "$_pid" ]; then
135		return
136	fi
137	_find_processes $_procname ${_interpreter:-.} '-p '"$_pid"
138}
139
140#
141# check_process procname [interpreter]
142#	Ensures that a process (or processes) named procname is running.
143#	Prints a list of matching PIDs.
144#	interpreter is optional; see _find_processes() for details.
145#
146check_process()
147{
148	_procname=$1
149	_interpreter=$2
150	if [ -z "$_procname" ]; then
151		err 3 'USAGE: check_process procname [interpreter]'
152	fi
153	_find_processes $_procname ${_interpreter:-.} '-ax'
154}
155
156#
157# _find_processes procname interpreter psargs
158#	Search for procname in the output of ps generated by psargs.
159#	Prints the PIDs of any matching processes, space separated.
160#
161#	If interpreter == ".", check the following variations of procname
162#	against the first word of each command:
163#		procname
164#		`basename procname`
165#		`basename procname` + ":"
166#		"(" + `basename procname` + ")"
167#
168#	If interpreter != ".", read the first line of procname, remove the
169#	leading #!, normalise whitespace, append procname, and attempt to
170#	match that against each command, either as is, or with extra words
171#	at the end.
172#
173_find_processes()
174{
175	if [ $# -ne 3 ]; then
176		err 3 'USAGE: _find_processes procname interpreter psargs'
177	fi
178	_procname=$1
179	_interpreter=$2
180	_psargs=$3
181
182	_pref=
183	if [ $_interpreter != "." ]; then	# an interpreted script
184		read _interp < $_procname	# read interpreter name
185		_interp=${_interp#\#!}		# strip #!
186		set -- $_interp
187		if [ $_interpreter != $1 ]; then
188			warn "\$command_interpreter $_interpreter != $1"
189		fi
190		_interp="$* $_procname"		# cleanup spaces, add _procname
191		_fp_args='_argv'
192		_fp_match='case "$_argv" in
193		    ${_interp}|"${_interp} "*)'
194	else					# a normal daemon
195		_procnamebn=${_procname##*/}
196		_fp_args='_arg0 _argv'
197		_fp_match='case "$_arg0" in
198		    $_procname|$_procnamebn|${_procnamebn}:|"(${_procnamebn})")'
199	fi
200
201	_proccheck='
202		ps -o "pid,command" '"$_psargs"' |
203		while read _npid '"$_fp_args"'; do
204			case "$_npid" in
205			    PID)
206				continue ;;
207			esac ; '"$_fp_match"'
208				echo -n "$_pref$_npid" ;
209				_pref=" "
210				;;
211			esac
212		done'
213
214#echo 1>&2 "proccheck is :$_proccheck:"
215	eval $_proccheck
216}
217
218#
219# wait_for_pids pid [pid ...]
220#	spins until none of the pids exist
221#
222wait_for_pids()
223{
224	_list="$@"
225	if [ -z "$_list" ]; then
226		return
227	fi
228	_prefix=
229	while true; do
230		_nlist="";
231		for _j in $_list; do
232			if kill -0 $_j 2>/dev/null; then
233				_nlist="${_nlist}${_nlist:+ }$_j"
234			fi
235		done
236		if [ -z "$_nlist" ]; then
237			break
238		fi
239		_list=$_nlist
240		echo -n ${_prefix:-"Waiting for PIDS: "}$_list
241		_prefix=", "
242		sleep 2
243	done
244	if [ -n "$_prefix" ]; then
245		echo "."
246	fi
247}
248
249#
250# run_rc_command argument
251#	Search for argument in the list of supported commands, which is:
252#		"start stop restart rcvar status poll ${extra_commands}"
253#	If there's a match, run ${argument}_cmd or the default method
254#	(see below).
255#
256#	If argument has a given prefix, then change the operation as follows:
257#		Prefix	Operation
258#		------	---------
259#		fast	Skip the pid check, and set rc_fast=yes
260#		force	Set ${rcvar} to YES, and set rc_force=yes
261#
262#	The following globals are used:
263#
264#	Name		Needed	Purpose
265#	----		------	-------
266#	name		y	Name of script.
267#
268#	command		n	Full path to command.
269#				Not needed if ${rc_arg}_cmd is set for
270#				each keyword.
271#
272#	command_args	n	Optional args/shell directives for command.
273#
274#	command_interpreter n	If not empty, command is interpreted, so
275#				call check_{pidfile,process}() appropriately.
276#
277#	extra_commands	n	List of extra commands supported.
278#
279#	pidfile		n	If set, use check_pidfile $pidfile $command,
280#				otherwise use check_process $command.
281#				In either case, only check if $command is set.
282#
283#	procname	n	Process name to check for instead of $command.
284#
285#	rcvar		n	This is checked with checkyesno to determine
286#				if the action should be run.
287#
288#	${name}_chroot	n	Directory to chroot to before running ${command}
289#				Requires /usr to be mounted.
290#
291#	${name}_chdir	n	Directory to cd to before running ${command}
292#				(if not using ${name}_chroot).
293#
294#	${name}_flags	n	Arguments to call ${command} with.
295#				NOTE:	$flags from the parent environment
296#					can be used to override this.
297#
298#	${name}_nice	n	Nice level to run ${command} at.
299#
300#	${name}_user	n	User to run ${command} as, using su(1) if not
301#				using ${name}_chroot.
302#				Requires /usr to be mounted.
303#
304#	${name}_group	n	Group to run chrooted ${command} as.
305#				Requires /usr to be mounted.
306#
307#	${name}_groups	n	Comma separated list of supplementary groups
308#				to run the chrooted ${command} with.
309#				Requires /usr to be mounted.
310#
311#	${name}_systrace n	Flags passed to systrace(1) if it is used.
312#				Setting this variable enables systracing
313# 				of the given program.  The use of "-a" is
314#				recommended so that the boot process is not
315#				stalled.  In order to pass no flags to
316#				systrace, set this variable to "--".
317#
318#	${rc_arg}_cmd	n	If set, use this as the method when invoked;
319#				Otherwise, use default command (see below)
320#
321#	${rc_arg}_precmd n	If set, run just before performing the
322#				${rc_arg}_cmd method in the default
323#				operation (i.e, after checking for required
324#				bits and process (non)existence).
325#				If this completes with a non-zero exit code,
326#				don't run ${rc_arg}_cmd.
327#
328#	${rc_arg}_postcmd n	If set, run just after performing the
329#				${rc_arg}_cmd method, if that method
330#				returned a zero exit code.
331#
332#	required_dirs	n	If set, check for the existence of the given
333#				directories before running the default
334#				(re)start command.
335#
336#	required_files	n	If set, check for the readability of the given
337#				files before running the default (re)start
338#				command.
339#
340#	required_vars	n	If set, perform checkyesno on each of the
341#				listed variables before running the default
342#				(re)start command.
343#
344#	Default behaviour for a given argument, if no override method is
345#	provided:
346#
347#	Argument	Default behaviour
348#	--------	-----------------
349#	start		if !running && checkyesno ${rcvar}
350#				${command}
351#
352#	stop		if ${pidfile}
353#				rc_pid=$(check_pidfile $pidfile $command)
354#			else
355#				rc_pid=$(check_process $command)
356#			kill $sig_stop $rc_pid
357#			wait_for_pids $rc_pid
358#			($sig_stop defaults to TERM.)
359#
360#	reload		Similar to stop, except use $sig_reload instead,
361#			and doesn't wait_for_pids.
362#			$sig_reload defaults to HUP.
363#
364#	restart		Run `stop' then `start'.
365#
366#	status		Show if ${command} is running, etc.
367#
368#	poll		Wait for ${command} to exit.
369#
370#	rcvar		Display what rc.conf variable is used (if any).
371#
372#	Variables available to methods, and after run_rc_command() has
373#	completed:
374#
375#	Variable	Purpose
376#	--------	-------
377#	rc_arg		Argument to command, after fast/force processing
378#			performed
379#
380#	rc_flags	Flags to start the default command with.
381#			Defaults to ${name}_flags, unless overridden
382#			by $flags from the environment.
383#			This variable may be changed by the precmd method.
384#
385#	rc_pid		PID of command (if appropriate)
386#
387#	rc_fast		Not empty if "fast" was provided (q.v.)
388#
389#	rc_force	Not empty if "force" was provided (q.v.)
390#
391#
392run_rc_command()
393{
394	rc_arg=$1
395	if [ -z "$name" ]; then
396		err 3 'run_rc_command: $name is not set.'
397	fi
398
399	case "$rc_arg" in
400	fast*)				# "fast" prefix; don't check pid
401		rc_arg=${rc_arg#fast}
402		rc_fast=yes
403		;;
404	force*)				# "force prefix; always start
405		rc_arg=${rc_arg#force}
406		rc_force=yes
407		if [ -n "${rcvar}" ]; then
408			eval ${rcvar}=YES
409		fi
410		;;
411	esac
412
413	_keywords="start stop restart rcvar $extra_commands"
414	rc_pid=
415	_pidcmd=
416	_procname=${procname:-${command}}
417
418					# setup pid check command if not fast
419	if [ -z "$rc_fast" -a -n "$_procname" ]; then
420		if [ -n "$pidfile" ]; then
421			_pidcmd='rc_pid=$(check_pidfile '"$pidfile $_procname $command_interpreter"')'
422		else
423			_pidcmd='rc_pid=$(check_process '"$_procname $command_interpreter"')'
424		fi
425		if [ -n "$_pidcmd" ]; then
426			_keywords="${_keywords} status poll"
427		fi
428	fi
429
430	if [ -z "$rc_arg" ]; then
431		rc_usage "$_keywords"
432	fi
433
434	if [ -n "$flags" ]; then	# allow override from environment
435		rc_flags=$flags
436	else
437		eval rc_flags=\$${name}_flags
438	fi
439	eval _chdir=\$${name}_chdir	_chroot=\$${name}_chroot \
440	    _nice=\$${name}_nice	_user=\$${name}_user \
441	    _group=\$${name}_group	_groups=\$${name}_groups \
442	    _systrace=\$${name}_systrace
443
444	if [ -n "$_user" ]; then	# unset $_user if running as that user
445		if [ "$_user" = "$(id -un)" ]; then
446			unset _user
447		fi
448	fi
449
450					# if ${rcvar} is set, and $1 is not
451					# "rcvar", then run
452					#	checkyesno ${rcvar}
453					# and return if that failed
454					#
455	if [ -n "${rcvar}" -a "$rc_arg" != "rcvar" ]; then
456		if ! checkyesno ${rcvar}; then
457			return 0
458		fi
459	fi
460
461	eval $_pidcmd			# determine the pid if necessary
462
463	for _elem in $_keywords; do
464		if [ "$_elem" != "$rc_arg" ]; then
465			continue
466		fi
467
468					# if there's a custom ${XXX_cmd},
469					# run that instead of the default
470					#
471		eval _cmd=\$${rc_arg}_cmd _precmd=\$${rc_arg}_precmd \
472		    _postcmd=\$${rc_arg}_postcmd
473		if [ -n "$_cmd" ]; then
474					# if the precmd failed and force
475					# isn't set, exit
476					#
477			if ! eval $_precmd && [ -z "$rc_force" ]; then
478				return 1
479			fi
480
481			if ! eval $_cmd && [ -z "$rc_force" ]; then
482				return 1
483			fi
484			eval $_postcmd
485			return 0
486		fi
487
488		case "$rc_arg" in	# default operations...
489
490		status)
491			if [ -n "$rc_pid" ]; then
492				echo "${name} is running as pid $rc_pid."
493			else
494				echo "${name} is not running."
495				return 1
496			fi
497			;;
498
499		start)
500			if [ -n "$rc_pid" ]; then
501				echo "${name} already running? (pid=$rc_pid)."
502				exit 1
503			fi
504
505			if [ ! -x ${_chroot}${command} ]; then
506				return 0
507			fi
508
509					# check for required variables,
510					# directories, and files
511					#
512			for _f in $required_vars; do
513				if ! checkyesno $_f; then
514					warn "\$${_f} is not set."
515					if [ -z "$rc_force" ]; then
516						return 1
517					fi
518				fi
519			done
520			for _f in $required_dirs; do
521				if [ ! -d "${_f}/." ]; then
522					warn "${_f} is not a directory."
523					if [ -z "$rc_force" ]; then
524						return 1
525					fi
526				fi
527			done
528			for _f in $required_files; do
529				if [ ! -r "${_f}" ]; then
530					warn "${_f} is not readable."
531					if [ -z "$rc_force" ]; then
532						return 1
533					fi
534				fi
535			done
536
537					# if the precmd failed and force
538					# isn't set, exit
539					#
540			if ! eval $_precmd && [ -z "$rc_force" ]; then
541				return 1
542			fi
543
544					# setup the command to run, and run it
545					#
546			echo "Starting ${name}."
547			if [ -n "$_chroot" ]; then
548				_doit="\
549${_nice:+nice -n $_nice }\
550${_systrace:+systrace $_systrace }\
551chroot ${_user:+-u $_user }${_group:+-g $_group }${_groups:+-G $_groups }\
552$_chroot $command $rc_flags $command_args"
553			else
554				_doit="\
555${_chdir:+cd $_chdir; }\
556${_nice:+nice -n $_nice }\
557${_systrace:+systrace $_systrace }\
558$command $rc_flags $command_args"
559				if [ -n "$_user" ]; then
560				    _doit="su -m $_user -c 'sh -c \"$_doit\"'"
561				fi
562			fi
563
564					# if the cmd failed and force
565					# isn't set, exit
566					#
567			if ! eval $_doit && [ -z "$rc_force" ]; then
568				return 1
569			fi
570
571					# finally, run postcmd
572					#
573			eval $_postcmd
574			;;
575
576		stop)
577			if [ -z "$rc_pid" ]; then
578				if [ -n "$pidfile" ]; then
579					echo \
580				    "${name} not running? (check $pidfile)."
581				else
582					echo "${name} not running?"
583				fi
584				exit 1
585			fi
586
587					# if the precmd failed and force
588					# isn't set, exit
589					#
590			if ! eval $_precmd && [ -z "$rc_force" ]; then
591				return 1
592			fi
593
594					# send the signal to stop
595					#
596			echo "Stopping ${name}."
597			_doit="kill -${sig_stop:-TERM} $rc_pid"
598			if [ -n "$_user" ]; then
599				_doit="su -m $_user -c 'sh -c \"$_doit\"'"
600			fi
601
602					# if the stop cmd failed and force
603					# isn't set, exit
604					#
605			if ! eval $_doit && [ -z "$rc_force" ]; then
606				return 1
607			fi
608
609					# wait for the command to exit,
610					# and run postcmd.
611			wait_for_pids $rc_pid
612			eval $_postcmd
613			;;
614
615		reload)
616			if [ -z "$rc_pid" ]; then
617				if [ -n "$pidfile" ]; then
618					echo \
619				    "${name} not running? (check $pidfile)."
620				else
621					echo "${name} not running?"
622				fi
623				exit 1
624			fi
625			echo "Reloading ${name} config files."
626			if ! eval $_precmd && [ -z "$rc_force" ]; then
627				return 1
628			fi
629			_doit="kill -${sig_reload:-HUP} $rc_pid"
630			if [ -n "$_user" ]; then
631				_doit="su -m $_user -c 'sh -c \"$_doit\"'"
632			fi
633			if ! eval $_doit && [ -z "$rc_force" ]; then
634				return 1
635			fi
636			eval $_postcmd
637			;;
638
639		restart)
640			if ! eval $_precmd && [ -z "$rc_force" ]; then
641				return 1
642			fi
643					# prevent restart being called more
644					# than once by any given script
645					#
646			if ${_rc_restart_done:-false}; then
647				return 0
648			fi
649			_rc_restart_done=true
650
651			( $0 ${rc_force:+force}stop )
652			$0 ${rc_force:+force}start
653
654			eval $_postcmd
655			;;
656
657		poll)
658			if [ -n "$rc_pid" ]; then
659				wait_for_pids $rc_pid
660			fi
661			;;
662
663		rcvar)
664			echo "# $name"
665			if [ -n "$rcvar" ]; then
666				if checkyesno ${rcvar}; then
667					echo "\$${rcvar}=YES"
668				else
669					echo "\$${rcvar}=NO"
670				fi
671			fi
672			;;
673
674		*)
675			rc_usage "$_keywords"
676			;;
677
678		esac
679		return 0
680	done
681
682	echo 1>&2 "$0: unknown directive '$rc_arg'."
683	rc_usage "$_keywords"
684	exit 1
685}
686
687#
688# run_rc_script file arg
689#	Start the script `file' with `arg', and correctly handle the
690#	return value from the script.  If `file' ends with `.sh', it's
691#	sourced into the current environment.  If `file' appears to be
692#	a backup or scratch file, ignore it.  Otherwise if it's
693#	executable run as a child process.
694#
695run_rc_script()
696{
697	_file=$1
698	_arg=$2
699	if [ -z "$_file" -o -z "$_arg" ]; then
700		err 3 'USAGE: run_rc_script file arg'
701	fi
702
703	unset	name command command_args command_interpreter \
704		extra_commands pidfile procname \
705		rcvar required_dirs required_files required_vars
706	eval unset ${_arg}_cmd ${_arg}_precmd ${_arg}_postcmd
707
708	case "$_file" in
709	*.sh)				# run in current shell
710		set $_arg ; . $_file
711		;;
712	*[~#]|*.OLD|*.orig)		# scratch file; skip
713		warn "Ignoring scratch file $_file"
714		;;
715	*)				# run in subshell
716		if [ -x $_file ]; then
717			if [ -n "$rc_fast_and_loose" ]; then
718				set $_arg ; . $_file
719			else
720				( set $_arg ; . $_file )
721			fi
722		fi
723		;;
724	esac
725}
726
727#
728# load_rc_config
729#	Source in the configuration file for a given command.
730#
731load_rc_config()
732{
733	_command=$1
734	if [ -z "$_command" ]; then
735		err 3 'USAGE: load_rc_config command'
736	fi
737
738	if ${_rc_conf_loaded:-false}; then
739		:
740	else
741		. /etc/rc.conf
742		_rc_conf_loaded=true
743	fi
744	if [ -f /etc/rc.conf.d/"$_command" ]; then
745		. /etc/rc.conf.d/"$_command"
746	fi
747}
748
749
750#
751# rc_usage commands
752#	Print a usage string for $0, with `commands' being a list of
753#	valid commands.
754#
755rc_usage()
756{
757	echo -n 1>&2 "Usage: $0 [fast|force]("
758
759	_sep=
760	for _elem; do
761		echo -n 1>&2 "$_sep$_elem"
762		_sep="|"
763	done
764	echo 1>&2 ")"
765	exit 1
766}
767
768#
769# err exitval message
770#	Display message to stderr and log to the syslog, and exit with exitval.
771#
772err()
773{
774	exitval=$1
775	shift
776
777	if [ -x /usr/bin/logger ]; then
778		logger "$0: ERROR: $*"
779	fi
780	echo 1>&2 "$0: ERROR: $*"
781	exit $exitval
782}
783
784#
785# warn message
786#	Display message to stderr and log to the syslog.
787#
788warn()
789{
790	if [ -x /usr/bin/logger ]; then
791		logger "$0: WARNING: $*"
792	fi
793	echo 1>&2 "$0: WARNING: $*"
794}
795
796#
797# backup_file action file cur backup
798#	Make a backup copy of `file' into `cur', and save the previous
799#	version of `cur' as `backup' or use rcs for archiving.
800#
801#	This routine checks the value of the backup_uses_rcs variable,
802#	which can be either YES or NO.
803#
804#	The `action' keyword can be one of the following:
805#
806#	add		`file' is now being backed up (and is possibly
807#			being reentered into the backups system).  `cur'
808#			is created and RCS files, if necessary, are
809#			created as well.
810#
811#	update		`file' has changed and needs to be backed up.
812#			If `cur' exists, it is copied to to `back' or
813#			checked into RCS (if the repository file is old),
814#			and then `file' is copied to `cur'.  Another RCS
815#			check in done here if RCS is being used.
816#
817#	remove		`file' is no longer being tracked by the backups
818#			system.  If RCS is not being used, `cur' is moved
819#			to `back', otherwise an empty file is checked in,
820#			and then `cur' is removed.
821#
822#
823backup_file()
824{
825	_action=$1
826	_file=$2
827	_cur=$3
828	_back=$4
829
830	if checkyesno backup_uses_rcs; then
831		_msg0="backup archive"
832		_msg1="update"
833
834		# ensure that history file is not locked
835		if [ -f $_cur,v ]; then
836			rcs -q -u -U -M $_cur
837		fi
838
839		# ensure after switching to rcs that the
840		# current backup is not lost
841		if [ -f $_cur ]; then
842			# no archive, or current newer than archive
843			if [ ! -f $_cur,v -o $_cur -nt $_cur,v ]; then
844				ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
845				rcs -q -kb -U $_cur
846				co -q -f -u $_cur
847			fi
848		fi
849
850		case $_action in
851		add|update)
852			cp -p $_file $_cur
853			ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
854			rcs -q -kb -U $_cur
855			co -q -f -u $_cur
856			chown root:wheel $_cur $_cur,v
857			;;
858		remove)
859			cp /dev/null $_cur
860			ci -q -f -u -t-"$_msg0" -m"$_msg1" $_cur
861			rcs -q -kb -U $_cur
862			chown root:wheel $_cur $_cur,v
863			rm $_cur
864			;;
865		esac
866	else
867		case $_action in
868		add|update)
869			if [ -f $_cur ]; then
870				cp -p $_cur $_back
871			fi
872			cp -p $_file $_cur
873			chown root:wheel $_cur
874			;;
875		remove)
876			mv -f $_cur $_back
877			;;
878		esac
879	fi
880}
881