xref: /freebsd/share/man/man8/rc.subr.8 (revision 271c3a9060f2ee55607ebe146523f888e1db2654)
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.\"
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10.\" modification, are permitted provided that the following conditions
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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.
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25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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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
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37.\" $FreeBSD$
38.\"
39.Dd May 18, 2007
40.Dt RC.SUBR 8
41.Os
42.Sh NAME
43.Nm rc.subr
44.Nd functions used by system shell scripts
45.Sh SYNOPSIS
46.Bl -item -compact
47.It
48.Ic .\& Pa /etc/rc.subr
49.Pp
50.It
51.Ic backup_file Ar action Ar file Ar current Ar backup
52.It
53.Ic checkyesno Ar var
54.It
55.Ic check_pidfile Ar pidfile Ar procname Op Ar interpreter
56.It
57.Ic check_process Ar procname Op Ar interpreter
58.It
59.Ic debug Ar message
60.It
61.Ic err Ar exitval Ar message
62.It
63.Ic force_depend Ar name
64.It
65.Ic info Ar message
66.It
67.Ic load_kld Oo Fl e Ar regex Oc Oo Fl m Ar module Oc Ar file
68.It
69.Ic load_rc_config Ar name
70.It
71.Ic load_rc_config_var Ar name Ar var
72.It
73.Ic mount_critical_filesystems Ar type
74.It
75.Ic rc_usage Ar command ...
76.It
77.Ic reverse_list Ar item ...
78.It
79.Ic run_rc_command Ar argument
80.It
81.Ic run_rc_script Ar file Ar argument
82.It
83.Ic set_rcvar Op Ar base
84.It
85.Ic wait_for_pids Op Ar pid ...
86.It
87.Ic warn Ar message
88.El
89.Sh DESCRIPTION
90The
91.Nm
92script
93contains commonly used shell script functions and variable
94definitions which are used by various scripts such as
95.Xr rc 8 .
96Scripts required by ports in
97.Pa /usr/local/etc/rc.d
98will also eventually
99be rewritten to make use of it.
100.Pp
101The
102.Nm
103functions were mostly imported from
104.Nx
105and it is intended that they remain synced between the
106two projects.
107With that in mind there are several variable
108definitions that can help in this regard.
109They are:
110.Bl -tag -width 4n
111.It Va OSTYPE
112Its value will be either
113.Qq Li FreeBSD
114or
115.Qq Li NetBSD ,
116depending on which OS it is running on.
117.It Va SYSCTL
118The path to the
119.Xr sysctl 8
120command.
121.It Va SYSCTL_N
122The path and argument list to display only the
123.Xr sysctl 8
124values instead of a
125.Ar name Ns = Ns Ar value
126pair.
127.It Va SYSCTL_W
128The path and argument to write or modify
129.Xr sysctl 8
130values.
131.El
132.Pp
133The
134.Nm
135functions are accessed by sourcing
136.Pa /etc/rc.subr
137into the current shell.
138.Pp
139The following shell functions are available:
140.Bl -tag -width 4n
141.It Ic backup_file Ar action file current backup
142Make a backup copy of
143.Ar file
144into
145.Ar current .
146If the
147.Xr rc.conf 5
148variable
149.Va backup_uses_rcs
150is
151.Dq Li YES ,
152use
153.Xr rcs 1
154to archive the previous version of
155.Ar current ,
156otherwise save the previous version of
157.Ar current
158as
159.Ar backup .
160.Pp
161The
162.Ar action
163argument
164may be one of the following:
165.Bl -tag -width ".Cm remove"
166.It Cm add
167.Ar file
168is now being backed up by or possibly re-entered into this backup mechanism.
169.Ar current
170is created, and if necessary, the
171.Xr rcs 1
172files are created as well.
173.It Cm update
174.Ar file
175has changed and needs to be backed up.
176If
177.Ar current
178exists, it is copied to
179.Ar backup
180or checked into
181.Xr rcs 1
182(if the repository file is old),
183and then
184.Ar file
185is copied to
186.Ar current .
187.It Cm remove
188.Ar file
189is no longer being tracked by this backup mechanism.
190If
191.Xr rcs 1
192is being used, an empty file is checked in and
193.Ar current
194is removed,
195otherwise
196.Ar current
197is moved to
198.Ar backup .
199.El
200.It Ic checkyesno Ar var
201Return 0 if
202.Ar var
203is defined to
204.Dq Li YES ,
205.Dq Li TRUE ,
206.Dq Li ON ,
207or
208.Ql 1 .
209Return 1 if
210.Ar var
211is defined to
212.Dq Li NO ,
213.Dq Li FALSE ,
214.Dq Li OFF ,
215or
216.Ql 0 .
217Otherwise, warn that
218.Ar var
219is not set correctly.
220The values are case insensitive.
221.Sy Note :
222.Ar var
223should be a variable name, not its value;
224.Ic checkyesno
225will expand the variable by itself.
226.It Ic check_pidfile Ar pidfile procname Op Ar interpreter
227Parses the first word of the first line of
228.Ar pidfile
229for a PID, and ensures that the process with that PID
230is running and its first argument matches
231.Ar procname .
232Prints the matching PID if successful, otherwise nothing.
233If
234.Ar interpreter
235is provided, parse the first line of
236.Ar procname ,
237ensure that the line is of the form:
238.Pp
239.Dl "#! interpreter [...]"
240.Pp
241and use
242.Ar interpreter
243with its optional arguments and
244.Ar procname
245appended as the process string to search for.
246.It Ic check_process Ar procname Op Ar interpreter
247Prints the PIDs of any processes that are running with a first
248argument that matches
249.Ar procname .
250.Ar interpreter
251is handled as per
252.Ic check_pidfile .
253.It Ic debug Ar message
254Display a debugging message to
255.Va stderr ,
256log it to the system log using
257.Xr logger 1 ,
258and
259return to the caller.
260The error message consists of the script name
261(from
262.Va $0 ) ,
263followed by
264.Dq Li ": DEBUG: " ,
265and then
266.Ar message .
267This function is intended to be used by developers
268as an aid to debugging scripts.
269It can be turned on or off
270by the
271.Xr rc.conf 5
272variable
273.Va rc_debug .
274.It Ic err Ar exitval message
275Display an error message to
276.Va stderr ,
277log it to the system log
278using
279.Xr logger 1 ,
280and
281.Ic exit
282with an exit value of
283.Ar exitval .
284The error message consists of the script name
285(from
286.Va $0 ) ,
287followed by
288.Dq Li ": ERROR: " ,
289and then
290.Ar message .
291.It Ic force_depend Ar name
292Output an advisory message and force the
293.Ar name
294service to start.
295The
296.Ar name
297argument is the
298.Xr basename 1
299component of the path to the script, usually
300.Pa /etc/rc.d/name .
301If the script fails for any reason it will output a warning
302and return with a return value of 1.
303If it was successful
304it will return 0.
305.It Ic info Ar message
306Display an informational message to
307.Va stdout ,
308and log it to the system log using
309.Xr logger 1 .
310The message consists of the script name
311(from
312.Va $0 ) ,
313followed by
314.Dq Li ": INFO: " ,
315and then
316.Ar message .
317The display of this informational output can be
318turned on or off by the
319.Xr rc.conf 5
320variable
321.Va rc_info .
322.It Ic load_kld Oo Fl e Ar regex Oc Oo Fl m Ar module Oc Ar file
323Load
324.Ar file
325as a kernel module unless it is already loaded.
326For the purpose of checking the module status,
327either the exact module name can be specified using
328.Fl m ,
329or an
330.Xr egrep 1
331regular expression matching the module name can be supplied via
332.Fl e .
333By default, the module is assumed to have the same name as
334.Ar file ,
335which is not always the case.
336.It Ic load_rc_config Ar name
337Source in the configuration files for
338.Ar name .
339First,
340.Pa /etc/rc.conf
341is sourced if it has not yet been read in.
342Then,
343.Pa /etc/rc.conf.d/ Ns Ar name
344is sourced if it is an existing file.
345The latter may also contain other variable assignments to override
346.Ic run_rc_command
347arguments defined by the calling script, to provide an easy
348mechanism for an administrator to override the behaviour of a given
349.Xr rc.d 8
350script without requiring the editing of that script.
351.It Ic load_rc_config_var Ar name Ar var
352Read the
353.Xr rc.conf 5
354variable
355.Ar var
356for
357.Ar name
358and set in the current shell, using
359.Ic load_rc_config
360in a sub-shell to prevent unwanted side effects from other variable
361assignments.
362.It Ic mount_critical_filesystems Ar type
363Go through a list of critical file systems,
364as found in the
365.Xr rc.conf 5
366variable
367.Va critical_filesystems_ Ns Ar type ,
368mounting each one that
369is not currently mounted.
370.It Ic rc_usage Ar command ...
371Print a usage message for
372.Va $0 ,
373with
374.Ar commands
375being the list of valid arguments
376prefixed by
377.Sm off
378.Dq Bq Li fast | force | one .
379.Sm on
380.It Ic reverse_list Ar item ...
381Print the list of
382.Ar items
383in reverse order.
384.It Ic run_rc_command Ar argument
385Run the
386.Ar argument
387method for the current
388.Xr rc.d 8
389script, based on the settings of various shell variables.
390.Ic run_rc_command
391is extremely flexible, and allows fully functional
392.Xr rc.d 8
393scripts to be implemented in a small amount of shell code.
394.Pp
395.Ar argument
396is searched for in the list of supported commands, which may be one
397of:
398.Bl -tag -width ".Cm restart" -offset indent
399.It Cm start
400Start the service.
401This should check that the service is to be started as specified by
402.Xr rc.conf 5 .
403Also checks if the service is already running and refuses to start if
404it is.
405This latter check is not performed by standard
406.Fx
407scripts if the system is starting directly to multi-user mode, to
408speed up the boot process.
409.It Cm stop
410If the service is to be started as specified by
411.Xr rc.conf 5 ,
412stop the service.
413This should check that the service is running and complain if it is not.
414.It Cm restart
415Perform a
416.Cm stop
417then a
418.Cm start .
419Defaults to displaying the process ID of the program (if running).
420.It Cm rcvar
421Display which
422.Xr rc.conf 5
423variables are used to control the startup of the service (if any).
424.El
425.Pp
426If
427.Va pidfile
428or
429.Va procname
430is set, also support:
431.Bl -tag -width ".Cm restart" -offset indent
432.It Cm poll
433Wait for the command to exit.
434.It Cm status
435Show the status of the process.
436.El
437.Pp
438Other supported commands are listed in the optional variable
439.Va extra_commands .
440.Pp
441.Ar argument
442may have one of the following prefixes which alters its operation:
443.Bl -tag -width ".Li force" -offset indent
444.It Li fast
445Skip the check for an existing running process,
446and sets
447.Va rc_fast Ns = Ns Li YES .
448.It Li force
449Skip the checks for
450.Va rcvar
451being set to
452.Dq Li YES ,
453and sets
454.Va rc_force Ns = Ns Li YES .
455This ignores
456.Ar argument Ns Va _precmd
457returning non-zero, and ignores any of the
458.Va required_*
459tests failing, and always returns a zero exit status.
460.It Li one
461Skip the checks for
462.Va rcvar
463being set to
464.Dq Li YES ,
465but performs all the other prerequisite tests.
466.El
467.Pp
468.Ic run_rc_command
469uses the following shell variables to control its behaviour.
470Unless otherwise stated, these are optional.
471.Bl -tag -width ".Va procname" -offset indent
472.It Va name
473The name of this script.
474This is not optional.
475.It Va rcvar
476The value of
477.Va rcvar
478is checked with
479.Ic checkyesno
480to determine if this method should be run.
481.It Va command
482Full path to the command.
483Not required if
484.Ar argument Ns Va _cmd
485is defined for each supported keyword.
486Can be overridden by
487.Va ${name}_program .
488.It Va command_args
489Optional arguments and/or shell directives for
490.Va command .
491.It Va command_interpreter
492.Va command
493is started with:
494.Pp
495.Dl "#! command_interpreter [...]"
496.Pp
497which results in its
498.Xr ps 1
499command being:
500.Pp
501.Dl "command_interpreter [...] command"
502.Pp
503so use that string to find the PID(s) of the running command
504rather than
505.Va command .
506.It Va extra_commands
507Extra commands/keywords/arguments supported.
508.It Va pidfile
509Path to PID file.
510Used to determine the PID(s) of the running command.
511If
512.Va pidfile
513is set, use:
514.Pp
515.Dl "check_pidfile $pidfile $procname"
516.Pp
517to find the PID.
518Otherwise, if
519.Va command
520is set, use:
521.Pp
522.Dl "check_process $procname"
523.Pp
524to find the PID.
525.It Va procname
526Process name to check for.
527Defaults to the value of
528.Va command .
529.It Va required_dirs
530Check for the existence of the listed directories
531before running the
532.Cm start
533method.
534.It Va required_files
535Check for the readability of the listed files
536before running the
537.Cm start
538method.
539.It Va required_modules
540Ensure that the listed kernel modules are loaded
541before running the
542.Cm start
543method.
544This is done after invoking the commands from
545.Va start_precmd
546so that the missing modules are not loaded in vain
547if the preliminary commands indicate a error condition.
548A word in the list can have an optional
549.Dq Li : Ns Ar modname
550or
551.Dq Li ~ Ns Ar pattern
552suffix.
553The
554.Ar modname
555or
556.Ar pattern
557parameter is passed to
558.Ic load_kld
559through a
560.Fl m
561or
562.Fl e
563option, respectively.
564See the description of
565.Ic load_kld
566in this document for details.
567.It Va required_vars
568Perform
569.Ic checkyesno
570on each of the list variables
571before running the
572.Cm start
573method.
574.It Va ${name}_chdir
575Directory to
576.Ic cd
577to before running
578.Va command ,
579if
580.Va ${name}_chroot
581is not provided.
582.It Va ${name}_chroot
583Directory to
584.Xr chroot 8
585to before running
586.Va command .
587Only supported after
588.Pa /usr
589is mounted.
590.It Va ${name}_flags
591Arguments to call
592.Va command
593with.
594This is usually set in
595.Xr rc.conf 5 ,
596and not in the
597.Xr rc.d 8
598script.
599The environment variable
600.Sq Ev flags
601can be used to override this.
602.It Va ${name}_nice
603.Xr nice 1
604level to run
605.Va command
606as.
607Only supported after
608.Pa /usr
609is mounted.
610.It Va ${name}_program
611Full path to the command.
612Overrides
613.Va command
614if both are set, but has no effect if
615.Va command
616is unset.
617As a rule,
618.Va command
619should be set in the script while
620.Va ${name}_program
621should be set in
622.Xr rc.conf 5 .
623.It Va ${name}_user
624User to run
625.Va command
626as, using
627.Xr chroot 8
628if
629.Va ${name}_chroot
630is set, otherwise
631uses
632.Xr su 1 .
633Only supported after
634.Pa /usr
635is mounted.
636.It Va ${name}_group
637Group to run the chrooted
638.Va command
639as.
640.It Va ${name}_groups
641Comma separated list of supplementary groups to run the chrooted
642.Va command
643with.
644.It Ar argument Ns Va _cmd
645Shell commands which override the default method for
646.Ar argument .
647.It Ar argument Ns Va _precmd
648Shell commands to run just before running
649.Ar argument Ns Va _cmd
650or the default method for
651.Ar argument .
652If this returns a non-zero exit code, the main method is not performed.
653If the default method is being executed, this check is performed after
654the
655.Va required_*
656checks and process (non-)existence checks.
657.It Ar argument Ns Va _postcmd
658Shell commands to run if running
659.Ar argument Ns Va _cmd
660or the default method for
661.Ar argument
662returned a zero exit code.
663.It Va sig_stop
664Signal to send the processes to stop in the default
665.Cm stop
666method.
667Defaults to
668.Dv SIGTERM .
669.It Va sig_reload
670Signal to send the processes to reload in the default
671.Cm reload
672method.
673Defaults to
674.Dv SIGHUP .
675.El
676.Pp
677For a given method
678.Ar argument ,
679if
680.Ar argument Ns Va _cmd
681is not defined, then a default method is provided by
682.Ic run_rc_command :
683.Bl -tag -width ".Sy Argument" -offset indent
684.It Sy Argument
685.Sy Default method
686.It Cm start
687If
688.Va command
689is not running and
690.Ic checkyesno Va rcvar
691succeeds, start
692.Va command .
693.It Cm stop
694Determine the PIDs of
695.Va command
696with
697.Ic check_pidfile
698or
699.Ic check_process
700(as appropriate),
701.Ic kill Va sig_stop
702those PIDs, and run
703.Ic wait_for_pids
704on those PIDs.
705.It Cm reload
706Similar to
707.Cm stop ,
708except that it uses
709.Va sig_reload
710instead, and does not run
711.Ic wait_for_pids .
712Another difference from
713.Cm stop
714is that
715.Cm reload
716is not provided by default.
717It can be enabled via
718.Va extra_commands
719if appropriate:
720.Pp
721.Dl "extra_commands=reload"
722.It Cm restart
723Runs the
724.Cm stop
725method, then the
726.Cm start
727method.
728.It Cm status
729Show the PID of
730.Va command ,
731or some other script specific status operation.
732.It Cm poll
733Wait for
734.Va command
735to exit.
736.It Cm rcvar
737Display which
738.Xr rc.conf 5
739variable is used (if any).
740This method always works, even if the appropriate
741.Xr rc.conf 5
742variable is set to
743.Dq Li NO .
744.El
745.Pp
746The following variables are available to the methods
747(such as
748.Ar argument Ns Va _cmd )
749as well as after
750.Ic run_rc_command
751has completed:
752.Bl -tag -width ".Va rc_flags" -offset indent
753.It Va rc_arg
754Argument provided to
755.Ic run_rc_command ,
756after fast and force processing has been performed.
757.It Va rc_flags
758Flags to start the default command with.
759Defaults to
760.Va ${name}_flags ,
761unless overridden by the environment variable
762.Sq Ev flags .
763This variable may be changed by the
764.Ar argument Ns Va _precmd
765method.
766.It Va rc_pid
767PID of
768.Va command
769(if appropriate).
770.It Va rc_fast
771Not empty if
772.Dq Li fast
773prefix was used.
774.It Va rc_force
775Not empty if
776.Dq Li force
777prefix was used.
778.El
779.It Ic run_rc_script Ar file argument
780Start the script
781.Ar file
782with an argument of
783.Ar argument ,
784and handle the return value from the script.
785.Pp
786Various shell variables are unset before
787.Ar file
788is started:
789.Bd -ragged -offset indent
790.Va name ,
791.Va command ,
792.Va command_args ,
793.Va command_interpreter ,
794.Va extra_commands ,
795.Va pidfile ,
796.Va rcvar ,
797.Va required_dirs ,
798.Va required_files ,
799.Va required_vars ,
800.Ar argument Ns Va _cmd ,
801.Ar argument Ns Va _precmd .
802.Ar argument Ns Va _postcmd .
803.Ed
804.Pp
805The startup behaviour of
806.Ar file
807depends upon the following checks:
808.Bl -enum
809.It
810If
811.Ar file
812ends in
813.Pa .sh ,
814it is sourced into the current shell.
815.It
816If
817.Ar file
818appears to be a backup or scratch file
819(e.g., with a suffix of
820.Pa ~ , # , .OLD ,
821or
822.Pa .orig ) ,
823ignore it.
824.It
825If
826.Ar file
827is not executable, ignore it.
828.It
829If the
830.Xr rc.conf 5
831variable
832.Va rc_fast_and_loose
833is empty,
834source
835.Ar file
836in a sub shell,
837otherwise source
838.Ar file
839into the current shell.
840.El
841.It Ic stop_boot Op Ar always
842Prevent booting to multiuser mode.
843If the
844.Va autoboot
845variable is set to
846.Ql yes ,
847or
848.Ic checkyesno Ar always
849indicates a truth value, then a
850.Dv SIGTERM
851signal is sent to the parent
852process, which is assumed to be
853.Xr rc 8 .
854Otherwise, the shell exits with a non-zero status.
855.It Ic set_rcvar Op Ar base
856Set the variable name required to start a service.
857In
858.Fx
859a daemon is usually controlled by an
860.Xr rc.conf 5
861variable consisting of a daemon's name postfixed by the string
862.Dq Li "_enable" .
863This is not the case in
864.Nx .
865When the following line is included in a script:
866.Pp
867.Dl "rcvar=`set_rcvar`"
868.Pp
869this function will use the value of the
870.Va $name
871variable, which should be defined by the calling script,
872to construct the appropriate
873.Xr rc.conf 5
874knob.
875If the
876.Ar base
877argument is set it will use
878.Ar base
879instead of
880.Va $name .
881.It Ic wait_for_pids Op Ar pid ...
882Wait until all of the provided
883.Ar pids
884do not exist any more, printing the list of outstanding
885.Ar pids
886every two seconds.
887.It Ic warn Ar message
888Display a warning message to
889.Va stderr
890and log it to the system log
891using
892.Xr logger 1 .
893The warning message consists of the script name
894(from
895.Va $0 ) ,
896followed by
897.Dq Li ": WARNING: " ,
898and then
899.Ar message .
900.El
901.Sh FILES
902.Bl -tag -width ".Pa /etc/rc.subr" -compact
903.It Pa /etc/rc.subr
904The
905.Nm
906file resides in
907.Pa /etc .
908.El
909.Sh SEE ALSO
910.Xr rc.conf 5 ,
911.Xr rc 8
912.Sh HISTORY
913The
914.Nm
915script
916appeared in
917.Nx 1.3 .
918The
919.Xr rc.d 8
920support functions appeared in
921.Nx 1.5 .
922The
923.Nm
924script
925first appeared in
926.Fx 5.0 .
927