xref: /freebsd/share/man/man8/rc.subr.8 (revision 2b15cb3d0922bd70ea592f0da9b4a5b167f4d53f)
1.\" 	$NetBSD: rc.subr.8,v 1.12 2004/01/06 00:52:24 lukem Exp $
2.\"
3.\" Copyright (c) 2002-2004 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.\"
18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28.\" POSSIBILITY OF SUCH DAMAGE.
29.\"
30.\" $FreeBSD$
31.\"
32.Dd October 12, 2014
33.Dt RC.SUBR 8
34.Os
35.Sh NAME
36.Nm rc.subr
37.Nd functions used by system shell scripts
38.Sh SYNOPSIS
39.Bl -item -compact
40.It
41.Ic .\& Pa /etc/rc.subr
42.Pp
43.It
44.Ic backup_file Ar action Ar file Ar current Ar backup
45.It
46.Ic checkyesno Ar var
47.It
48.Ic check_pidfile Ar pidfile Ar procname Op Ar interpreter
49.It
50.Ic check_process Ar procname Op Ar interpreter
51.It
52.Ic debug Ar message
53.It
54.Ic err Ar exitval Ar message
55.It
56.Ic force_depend Ar name
57.It
58.Ic info Ar message
59.It
60.Ic load_kld Oo Fl e Ar regex Oc Oo Fl m Ar module Oc Ar file
61.It
62.Ic load_rc_config Ar name
63.It
64.Ic load_rc_config_var Ar name Ar var
65.It
66.Ic mount_critical_filesystems Ar type
67.It
68.Ic rc_usage Ar command ...
69.It
70.Ic reverse_list Ar item ...
71.It
72.Ic run_rc_command Ar argument
73.It
74.Ic run_rc_script Ar file Ar argument
75.It
76.Ic wait_for_pids Op Ar pid ...
77.It
78.Ic warn Ar message
79.El
80.Sh DESCRIPTION
81The
82.Nm
83script
84contains commonly used shell script functions and variable
85definitions which are used by various scripts such as
86.Xr rc 8 .
87Scripts required by ports in
88.Pa /usr/local/etc/rc.d
89will also eventually
90be rewritten to make use of it.
91.Pp
92The
93.Nm
94functions were mostly imported from
95.Nx .
96.Pp
97They are accessed by sourcing
98.Pa /etc/rc.subr
99into the current shell.
100.Pp
101The following shell functions are available:
102.Bl -tag -width 4n
103.It Ic backup_file Ar action file current backup
104Make a backup copy of
105.Ar file
106into
107.Ar current .
108If the
109.Xr rc.conf 5
110variable
111.Va backup_uses_rcs
112is
113.Dq Li YES ,
114use
115.Xr rcs 1
116to archive the previous version of
117.Ar current ,
118otherwise save the previous version of
119.Ar current
120as
121.Ar backup .
122.Pp
123The
124.Ar action
125argument
126may be one of the following:
127.Bl -tag -width ".Cm remove"
128.It Cm add
129.Ar file
130is now being backed up by or possibly re-entered into this backup mechanism.
131.Ar current
132is created, and if necessary, the
133.Xr rcs 1
134files are created as well.
135.It Cm update
136.Ar file
137has changed and needs to be backed up.
138If
139.Ar current
140exists, it is copied to
141.Ar backup
142or checked into
143.Xr rcs 1
144(if the repository file is old),
145and then
146.Ar file
147is copied to
148.Ar current .
149.It Cm remove
150.Ar file
151is no longer being tracked by this backup mechanism.
152If
153.Xr rcs 1
154is being used, an empty file is checked in and
155.Ar current
156is removed,
157otherwise
158.Ar current
159is moved to
160.Ar backup .
161.El
162.It Ic checkyesno Ar var
163Return 0 if
164.Ar var
165is defined to
166.Dq Li YES ,
167.Dq Li TRUE ,
168.Dq Li ON ,
169or
170.Ql 1 .
171Return 1 if
172.Ar var
173is defined to
174.Dq Li NO ,
175.Dq Li FALSE ,
176.Dq Li OFF ,
177or
178.Ql 0 .
179Otherwise, warn that
180.Ar var
181is not set correctly.
182The values are case insensitive.
183.Sy Note :
184.Ar var
185should be a variable name, not its value;
186.Ic checkyesno
187will expand the variable by itself.
188.It Ic check_pidfile Ar pidfile procname Op Ar interpreter
189Parses the first word of the first line of
190.Ar pidfile
191for a PID, and ensures that the process with that PID
192is running and its first argument matches
193.Ar procname .
194Prints the matching PID if successful, otherwise nothing.
195If
196.Ar interpreter
197is provided, parse the first line of
198.Ar procname ,
199ensure that the line is of the form:
200.Pp
201.Dl "#! interpreter [...]"
202.Pp
203and use
204.Ar interpreter
205with its optional arguments and
206.Ar procname
207appended as the process string to search for.
208.It Ic check_process Ar procname Op Ar interpreter
209Prints the PIDs of any processes that are running with a first
210argument that matches
211.Ar procname .
212.Ar interpreter
213is handled as per
214.Ic check_pidfile .
215.It Ic debug Ar message
216Display a debugging message to
217.Va stderr ,
218log it to the system log using
219.Xr logger 1 ,
220and
221return to the caller.
222The error message consists of the script name
223(from
224.Va $0 ) ,
225followed by
226.Dq Li ": DEBUG: " ,
227and then
228.Ar message .
229This function is intended to be used by developers
230as an aid to debugging scripts.
231It can be turned on or off
232by the
233.Xr rc.conf 5
234variable
235.Va rc_debug .
236.It Ic err Ar exitval message
237Display an error message to
238.Va stderr ,
239log it to the system log
240using
241.Xr logger 1 ,
242and
243.Ic exit
244with an exit value of
245.Ar exitval .
246The error message consists of the script name
247(from
248.Va $0 ) ,
249followed by
250.Dq Li ": ERROR: " ,
251and then
252.Ar message .
253.It Ic force_depend Ar name
254Output an advisory message and force the
255.Ar name
256service to start.
257The
258.Ar name
259argument is the
260.Xr basename 1
261component of the path to the script, usually
262.Pa /etc/rc.d/name .
263If the script fails for any reason it will output a warning
264and return with a return value of 1.
265If it was successful
266it will return 0.
267.It Ic info Ar message
268Display an informational message to
269.Va stdout ,
270and log it to the system log using
271.Xr logger 1 .
272The message consists of the script name
273(from
274.Va $0 ) ,
275followed by
276.Dq Li ": INFO: " ,
277and then
278.Ar message .
279The display of this informational output can be
280turned on or off by the
281.Xr rc.conf 5
282variable
283.Va rc_info .
284.It Ic load_kld Oo Fl e Ar regex Oc Oo Fl m Ar module Oc Ar file
285Load
286.Ar file
287as a kernel module unless it is already loaded.
288For the purpose of checking the module status,
289either the exact module name can be specified using
290.Fl m ,
291or an
292.Xr egrep 1
293regular expression matching the module name can be supplied via
294.Fl e .
295By default, the module is assumed to have the same name as
296.Ar file ,
297which is not always the case.
298.It Ic load_rc_config Ar name
299Source in the configuration files for
300.Ar name .
301First,
302.Pa /etc/rc.conf
303is sourced if it has not yet been read in.
304Then,
305.Pa /etc/rc.conf.d/ Ns Ar name
306is sourced if it is an existing file.
307The latter may also contain other variable assignments to override
308.Ic run_rc_command
309arguments defined by the calling script, to provide an easy
310mechanism for an administrator to override the behaviour of a given
311.Xr rc.d 8
312script without requiring the editing of that script.
313.It Ic load_rc_config_var Ar name Ar var
314Read the
315.Xr rc.conf 5
316variable
317.Ar var
318for
319.Ar name
320and set in the current shell, using
321.Ic load_rc_config
322in a sub-shell to prevent unwanted side effects from other variable
323assignments.
324.It Ic mount_critical_filesystems Ar type
325Go through a list of critical file systems,
326as found in the
327.Xr rc.conf 5
328variable
329.Va critical_filesystems_ Ns Ar type ,
330mounting each one that
331is not currently mounted.
332.It Ic rc_usage Ar command ...
333Print a usage message for
334.Va $0 ,
335with
336.Ar commands
337being the list of valid arguments
338prefixed by
339.Sm off
340.Dq Bq Li fast | force | one | quiet .
341.Sm on
342.It Ic reverse_list Ar item ...
343Print the list of
344.Ar items
345in reverse order.
346.It Ic run_rc_command Ar argument
347Run the
348.Ar argument
349method for the current
350.Xr rc.d 8
351script, based on the settings of various shell variables.
352.Ic run_rc_command
353is extremely flexible, and allows fully functional
354.Xr rc.d 8
355scripts to be implemented in a small amount of shell code.
356.Pp
357.Ar argument
358is searched for in the list of supported commands, which may be one
359of:
360.Bl -tag -width ".Cm restart" -offset indent
361.It Cm start
362Start the service.
363This should check that the service is to be started as specified by
364.Xr rc.conf 5 .
365Also checks if the service is already running and refuses to start if
366it is.
367This latter check is not performed by standard
368.Fx
369scripts if the system is starting directly to multi-user mode, to
370speed up the boot process.
371.It Cm stop
372If the service is to be started as specified by
373.Xr rc.conf 5 ,
374stop the service.
375This should check that the service is running and complain if it is not.
376.It Cm restart
377Perform a
378.Cm stop
379then a
380.Cm start .
381Defaults to displaying the process ID of the program (if running).
382.It Cm enabled
383Return 0 if the service is enabled and 1 if it is not.
384This command does not print anything.
385.It Cm rcvar
386Display which
387.Xr rc.conf 5
388variables are used to control the startup of the service (if any).
389.El
390.Pp
391If
392.Va pidfile
393or
394.Va procname
395is set, also support:
396.Bl -tag -width ".Cm restart" -offset indent
397.It Cm poll
398Wait for the command to exit.
399.It Cm status
400Show the status of the process.
401.El
402.Pp
403Other supported commands are listed in the optional variable
404.Va extra_commands .
405.Pp
406.Ar argument
407may have one of the following prefixes which alters its operation:
408.Bl -tag -width ".Li force" -offset indent
409.It Li fast
410Skip the check for an existing running process,
411and sets
412.Va rc_fast Ns = Ns Li YES .
413.It Li force
414Skip the checks for
415.Va rcvar
416being set to
417.Dq Li YES ,
418and sets
419.Va rc_force Ns = Ns Li YES .
420This ignores
421.Ar argument Ns Va _precmd
422returning non-zero, and ignores any of the
423.Va required_*
424tests failing, and always returns a zero exit status.
425.It Li one
426Skip the checks for
427.Va rcvar
428being set to
429.Dq Li YES ,
430but performs all the other prerequisite tests.
431.It Li quiet
432Inhibits some verbose diagnostics.
433Currently, this includes messages
434.Qq Starting ${name}
435(as checked by
436.Ic check_startmsgs
437inside
438.Nm )
439and errors about usage of services that are not enabled in
440.Xr rc.conf 5 .
441This prefix also sets
442.Va rc_quiet Ns = Ns Li YES .
443.Em Please, note:
444.Va rc_quiet
445is not intended to completely mask all debug and warning messages,
446but only certain small classes of them.
447.El
448.Pp
449.Ic run_rc_command
450uses the following shell variables to control its behaviour.
451Unless otherwise stated, these are optional.
452.Bl -tag -width ".Va procname" -offset indent
453.It Va name
454The name of this script.
455This is not optional.
456.It Va rcvar
457The value of
458.Va rcvar
459is checked with
460.Ic checkyesno
461to determine if this method should be run.
462.It Va command
463Full path to the command.
464Not required if
465.Ar argument Ns Va _cmd
466is defined for each supported keyword.
467Can be overridden by
468.Va ${name}_program .
469.It Va command_args
470Optional arguments and/or shell directives for
471.Va command .
472.It Va command_interpreter
473.Va command
474is started with:
475.Pp
476.Dl "#! command_interpreter [...]"
477.Pp
478which results in its
479.Xr ps 1
480command being:
481.Pp
482.Dl "command_interpreter [...] command"
483.Pp
484so use that string to find the PID(s) of the running command
485rather than
486.Va command .
487.It Va extra_commands
488Extra commands/keywords/arguments supported.
489.It Va pidfile
490Path to PID file.
491Used to determine the PID(s) of the running command.
492If
493.Va pidfile
494is set, use:
495.Pp
496.Dl "check_pidfile $pidfile $procname"
497.Pp
498to find the PID.
499Otherwise, if
500.Va command
501is set, use:
502.Pp
503.Dl "check_process $procname"
504.Pp
505to find the PID.
506.It Va procname
507Process name to check for.
508Defaults to the value of
509.Va command .
510.It Va required_dirs
511Check for the existence of the listed directories
512before running the
513.Cm start
514method.
515.It Va required_files
516Check for the readability of the listed files
517before running the
518.Cm start
519method.
520.It Va required_modules
521Ensure that the listed kernel modules are loaded
522before running the
523.Cm start
524method.
525This is done after invoking the commands from
526.Va start_precmd
527so that the missing modules are not loaded in vain
528if the preliminary commands indicate a error condition.
529A word in the list can have an optional
530.Dq Li : Ns Ar modname
531or
532.Dq Li ~ Ns Ar pattern
533suffix.
534The
535.Ar modname
536or
537.Ar pattern
538parameter is passed to
539.Ic load_kld
540through a
541.Fl m
542or
543.Fl e
544option, respectively.
545See the description of
546.Ic load_kld
547in this document for details.
548.It Va required_vars
549Perform
550.Ic checkyesno
551on each of the list variables
552before running the
553.Cm start
554method.
555.It Va ${name}_chdir
556Directory to
557.Ic cd
558to before running
559.Va command ,
560if
561.Va ${name}_chroot
562is not provided.
563.It Va ${name}_chroot
564Directory to
565.Xr chroot 8
566to before running
567.Va command .
568Only supported after
569.Pa /usr
570is mounted.
571.It Va ${name}_env
572A list of environment variables to run
573.Va command
574with.
575This will be passed as arguments to
576.Xr env 1
577utility.
578.It Va ${name}_fib
579FIB
580.Pa Routing Table
581number to run
582.Va command
583with.
584See
585.Xr setfib 1
586for more details.
587.It Va ${name}_flags
588Arguments to call
589.Va command
590with.
591This is usually set in
592.Xr rc.conf 5 ,
593and not in the
594.Xr rc.d 8
595script.
596The environment variable
597.Sq Ev flags
598can be used to override this.
599.It Va ${name}_nice
600.Xr nice 1
601level to run
602.Va command
603as.
604Only supported after
605.Pa /usr
606is mounted.
607.It Va ${name}_program
608Full path to the command.
609Overrides
610.Va command
611if both are set, but has no effect if
612.Va command
613is unset.
614As a rule,
615.Va command
616should be set in the script while
617.Va ${name}_program
618should be set in
619.Xr rc.conf 5 .
620.It Va ${name}_user
621User to run
622.Va command
623as, using
624.Xr chroot 8
625if
626.Va ${name}_chroot
627is set, otherwise
628uses
629.Xr su 1 .
630Only supported after
631.Pa /usr
632is mounted.
633.It Va ${name}_group
634Group to run the chrooted
635.Va command
636as.
637.It Va ${name}_groups
638Comma separated list of supplementary groups to run the chrooted
639.Va command
640with.
641.It Va ${name}_prepend
642Commands to be prepended to
643.Va command .
644This is a generic version of
645.Va ${name}_env ,
646.Va ${name}_fib ,
647or
648.Va ${name}_nice .
649.It Ar argument Ns Va _cmd
650Shell commands which override the default method for
651.Ar argument .
652.It Ar argument Ns Va _precmd
653Shell commands to run just before running
654.Ar argument Ns Va _cmd
655or the default method for
656.Ar argument .
657If this returns a non-zero exit code, the main method is not performed.
658If the default method is being executed, this check is performed after
659the
660.Va required_*
661checks and process (non-)existence checks.
662.It Ar argument Ns Va _postcmd
663Shell commands to run if running
664.Ar argument Ns Va _cmd
665or the default method for
666.Ar argument
667returned a zero exit code.
668.It Va sig_stop
669Signal to send the processes to stop in the default
670.Cm stop
671method.
672Defaults to
673.Dv SIGTERM .
674.It Va sig_reload
675Signal to send the processes to reload in the default
676.Cm reload
677method.
678Defaults to
679.Dv SIGHUP .
680.El
681.Pp
682For a given method
683.Ar argument ,
684if
685.Ar argument Ns Va _cmd
686is not defined, then a default method is provided by
687.Ic run_rc_command :
688.Bl -tag -width ".Sy Argument" -offset indent
689.It Sy Argument
690.Sy Default method
691.It Cm start
692If
693.Va command
694is not running and
695.Ic checkyesno Va rcvar
696succeeds, start
697.Va command .
698.It Cm stop
699Determine the PIDs of
700.Va command
701with
702.Ic check_pidfile
703or
704.Ic check_process
705(as appropriate),
706.Ic kill Va sig_stop
707those PIDs, and run
708.Ic wait_for_pids
709on those PIDs.
710.It Cm reload
711Similar to
712.Cm stop ,
713except that it uses
714.Va sig_reload
715instead, and does not run
716.Ic wait_for_pids .
717Another difference from
718.Cm stop
719is that
720.Cm reload
721is not provided by default.
722It can be enabled via
723.Va extra_commands
724if appropriate:
725.Pp
726.Dl "extra_commands=reload"
727.It Cm restart
728Runs the
729.Cm stop
730method, then the
731.Cm start
732method.
733.It Cm status
734Show the PID of
735.Va command ,
736or some other script specific status operation.
737.It Cm poll
738Wait for
739.Va command
740to exit.
741.It Cm rcvar
742Display which
743.Xr rc.conf 5
744variable is used (if any).
745This method always works, even if the appropriate
746.Xr rc.conf 5
747variable is set to
748.Dq Li NO .
749.El
750.Pp
751The following variables are available to the methods
752(such as
753.Ar argument Ns Va _cmd )
754as well as after
755.Ic run_rc_command
756has completed:
757.Bl -tag -width ".Va rc_flags" -offset indent
758.It Va rc_arg
759Argument provided to
760.Ic run_rc_command ,
761after fast and force processing has been performed.
762.It Va rc_flags
763Flags to start the default command with.
764Defaults to
765.Va ${name}_flags ,
766unless overridden by the environment variable
767.Sq Ev flags .
768This variable may be changed by the
769.Ar argument Ns Va _precmd
770method.
771.It Va rc_pid
772PID of
773.Va command
774(if appropriate).
775.It Va rc_fast
776Not empty if
777.Dq Li fast
778prefix was used.
779.It Va rc_force
780Not empty if
781.Dq Li force
782prefix was used.
783.El
784.It Ic run_rc_script Ar file argument
785Start the script
786.Ar file
787with an argument of
788.Ar argument ,
789and handle the return value from the script.
790.Pp
791Various shell variables are unset before
792.Ar file
793is started:
794.Bd -ragged -offset indent
795.Va name ,
796.Va command ,
797.Va command_args ,
798.Va command_interpreter ,
799.Va extra_commands ,
800.Va pidfile ,
801.Va rcvar ,
802.Va required_dirs ,
803.Va required_files ,
804.Va required_vars ,
805.Ar argument Ns Va _cmd ,
806.Ar argument Ns Va _precmd .
807.Ar argument Ns Va _postcmd .
808.Ed
809.Pp
810The startup behaviour of
811.Ar file
812depends upon the following checks:
813.Bl -enum
814.It
815If
816.Ar file
817ends in
818.Pa .sh ,
819it is sourced into the current shell.
820.It
821If
822.Ar file
823appears to be a backup or scratch file
824(e.g., with a suffix of
825.Pa ~ , # , .OLD ,
826or
827.Pa .orig ) ,
828ignore it.
829.It
830If
831.Ar file
832is not executable, ignore it.
833.It
834If the
835.Xr rc.conf 5
836variable
837.Va rc_fast_and_loose
838is empty,
839source
840.Ar file
841in a sub shell,
842otherwise source
843.Ar file
844into the current shell.
845.El
846.It Ic stop_boot Op Ar always
847Prevent booting to multiuser mode.
848If the
849.Va autoboot
850variable is set to
851.Ql yes ,
852or
853.Ic checkyesno Ar always
854indicates a truth value, then a
855.Dv SIGTERM
856signal is sent to the parent
857process, which is assumed to be
858.Xr rc 8 .
859Otherwise, the shell exits with a non-zero status.
860.It Ic wait_for_pids Op Ar pid ...
861Wait until all of the provided
862.Ar pids
863do not exist any more, printing the list of outstanding
864.Ar pids
865every two seconds.
866.It Ic warn Ar message
867Display a warning message to
868.Va stderr
869and log it to the system log
870using
871.Xr logger 1 .
872The warning message consists of the script name
873(from
874.Va $0 ) ,
875followed by
876.Dq Li ": WARNING: " ,
877and then
878.Ar message .
879.El
880.Sh FILES
881.Bl -tag -width ".Pa /etc/rc.subr" -compact
882.It Pa /etc/rc.subr
883The
884.Nm
885file resides in
886.Pa /etc .
887.El
888.Sh SEE ALSO
889.Xr rc.conf 5 ,
890.Xr rc 8
891.Sh HISTORY
892The
893.Nm
894script
895appeared in
896.Nx 1.3 .
897The
898.Xr rc.d 8
899support functions appeared in
900.Nx 1.5 .
901The
902.Nm
903script
904first appeared in
905.Fx 5.0 .
906