xref: /freebsd/usr.sbin/sysrc/sysrc.8 (revision e17f5b1d307b7b8910d67883e57a9604305906d5)
1.\" Copyright (c) 2011-2016 Devin Teske
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25.\" $FreeBSD$
26.\"
27.Dd February 26, 2019
28.Dt SYSRC 8
29.Os
30.Sh NAME
31.Nm sysrc
32.Nd safely edit system rc files
33.Sh SYNOPSIS
34.Nm
35.Op Fl cdDeEFhinNqvx
36.Op Fl s Ar name
37.Op Fl f Ar file
38.Op Fl j Ar jail | Fl R Ar dir
39.Ar name Ns Op Ns Oo +|- Oc Ns = Ns Ar value
40.Ar ...
41.Nm
42.Op Fl cdDeEFhinNqvx
43.Op Fl s Ar name
44.Op Fl f Ar file
45.Op Fl j Ar jail | Fl R Ar dir
46.Fl a | A
47.Nm
48.Op Fl E
49.Op Fl s Ar name
50.Op Fl f Ar file
51.Fl l
52.Nm
53.Op Fl eEqv
54.Fl L
55.Op Ar name ...
56.Sh DESCRIPTION
57The
58.Nm
59utility retrieves
60.Xr rc.conf 5
61variables from the collection of system rc files and allows processes with
62appropriate privilege to change values in a safe and effective manner.
63.Pp
64The following options are available:
65.Bl -tag -width indent+
66.It Fl a
67Dump a list of all non-default configuration variables.
68.It Fl A
69Dump a list of all configuration variables
70.Pq incl. defaults .
71.It Fl c
72Check only.
73For querying, return success if all requested variables are set
74.Pq even if NULL ,
75otherwise return error status.
76For assignments, return success if no changes are required, otherwise failure.
77If verbose
78.Pq see Dq Fl v
79prints a message stating whether variables are set and/or changes are required.
80.It Fl d
81Print a description of the given variable.
82.It Fl D
83Show default value(s) only (this is the same as setting RC_CONFS to NULL or
84passing `-f' with a NULL file-argument).
85.It Fl e
86Print query results as
87.Xr sh 1
88compatible syntax
89.Pq for example, Ql var=value .
90Ignored if either
91.Ql Fl n
92or
93.Ql Fl F
94is specified.
95.It Fl E
96When given
97.Sq Fl l
98or
99.Sq Fl L
100to list configuration files, only list those that exist.
101When changing a setting, prefer to modify existing files.
102.It Fl f Ar file
103Operate on the specified file(s) instead of the files obtained by reading the
104.Sq rc_conf_files
105entry in the
106.Ev RC_DEFAULTS
107file.
108This option can be specified multiple times for additional files.
109.It Fl F
110Show only the last
111.Xr rc.conf 5
112file each directive is in.
113.It Fl h
114Print a short usage message to stderr and exit.
115.It Fl -help
116Print a full usage statement to stderr and exit.
117.It Fl i
118Ignore unknown variables.
119.It Fl j Ar jail
120The
121.Ar jid
122or name of the
123.Ar jail
124to operate within
125.Pq overrides So Fl R Ar dir Sc ; requires Xr jexec 8 .
126.It Fl l
127List configuration files used at startup on stdout and exit.
128.It Fl L
129List all configuration files including rc.conf.d entries on stdout and exit.
130Can be combined with
131.Sq Fl v
132or
133.Sq Fl e
134to show service names.
135.Nm
136exits with success if all named services are installed, failure otherwise.
137.It Fl n
138Show only variable values, not their names.
139.It Fl N
140Show only variable names, not their values.
141.It Fl q
142Quiet.
143Disable verbose and hide certain errors.
144When combined with
145.Sq Fl L
146and one or more
147.Ar name
148arguments, provide only exit status and no output.
149.It Fl R Ar dir
150Operate within the root directory
151.Sq Ar dir
152rather than
153.Sq / .
154.It Fl s Ar name
155If an
156.Li rc.d
157script of
158.Ar name
159exists
160.Po
161in
162.Dq /etc/rc.d
163or
164.Li local_startup
165directories
166.Pc ,
167process its
168.Dq rc.conf.d
169entries as potential overrides to
170.Sq rc_conf_files .
171See
172.Xr rc.subr 8
173for additional information on
174.Dq rc.conf.d .
175Can be combined with
176.Sq Fl l
177to list configuration files used by service at startup.
178.It Fl v
179Verbose.
180Print the pathname of the specific
181.Xr rc.conf 5
182file where the directive was found.
183.It Fl -version
184Print version information to stdout and exit.
185.It Fl x
186Remove variable(s) from specified file(s).
187.El
188.Pp
189This utility has a similar syntax to
190.Xr sysctl 8 .
191It shares the `-e' and `-n' options
192.Pq detailed above
193and also has the same
194.Ql name[=value]
195syntax for making queries/assignments.
196In addition
197.Pq but unlike Xr sysctl 8 ,
198.Ql name+=value
199is supported for adding items to values
200.Pq see APPENDING VALUES
201and
202.Ql name-=value
203is supported for removing items from values
204.Pq see SUBTRACTING VALUES .
205.Pp
206However, while
207.Xr sysctl 8
208serves to query/modify MIBs in the entrant kernel,
209.Nm
210instead works on values in the system
211.Xr rc.conf 5
212configuration files.
213.Pp
214The list of system configuration files is configured in the file
215.Ql /etc/defaults/rc.conf
216within the variable
217.Ql rc_conf_files ,
218which by-default contains a space-separated list of pathnames.
219On all
220.Fx
221systems, this defaults to the value "/etc/rc.conf /etc/rc.conf.local".
222Each
223pathname is sourced in-order upon startup.
224It is in the same fashion that
225.Nm
226sources the configuration files before returning the value of the given
227variable.
228.Pp
229When supplied a variable name,
230.Nm
231will return the value of the variable.
232If the variable does not appear in any
233of the configured
234.Ql rc_conf_files ,
235an error is printed and error status is returned.
236.Pp
237When changing values of a given variable, it does not matter if the variable
238appears in any of the
239.Ql rc_conf_files
240or not.
241If the variable does not appear in any of the files, it is appended to
242the end of the first pathname in the
243.Ql rc_conf_files
244variable.
245Otherwise,
246.Nm
247will replace only the last-occurrence in the last-file found to contain the
248variable.
249This gets the value to take effect next boot without heavily
250modifying these integral files (yet taking care not to allow the file to
251grow unwieldy should
252.Nm
253be called repeatedly).
254.Sh APPENDING VALUES
255When using the
256.Ql key+=value
257syntax to add items to existing values,
258the first character of the value is taken as the delimiter separating items
259.Pq usually Qo " " Qc or Qo , Qc .
260For example, in the following statement:
261.Bl -item -offset indent
262.It
263.Nm
264cloned_interfaces+=" gif0"
265.El
266.Pp
267the first character is a space, informing
268.Nm
269that existing values are to be considered separated by whitespace.
270If
271.Ql gif0
272is not found in the existing value for
273.Va cloned_interfaces ,
274it is added
275.Pq with delimiter only if existing value is non-NULL .
276.Pp
277For convenience, if the first character is alpha-numeric
278.Pq letters A-Z, a-z, or numbers 0-9 ,
279dot
280.Pq Li \&. ,
281or slash
282.Pq Li / ,
283.Nm
284uses the default setting of whitespace as separator.
285For example, the above and below statements are equivalent since
286.Dq gif0
287starts with an alpha-numeric character
288.Pq the letter Li g :
289.Bl -item -offset indent
290.It
291.Nm
292cloned_interfaces+=gif0
293.El
294.Pp
295Take the following sequence for example:
296.Bl -item -offset indent
297.It
298.Nm
299cloned_interfaces= # start with NULL
300.It
301.Nm
302cloned_interfaces+=gif0
303.Dl # NULL -> `gif0' Pq NB: no preceding delimiter
304.It
305.Nm
306cloned_interfaces+=gif0 # no change
307.It
308.Nm
309cloned_interfaces+="tun0 gif0"
310.Dl # `gif0' -> `gif0 tun0' Pq NB: no duplication
311.El
312.Pp
313.Nm
314prevents the same value from being added if already there.
315.Sh SUBTRACTING VALUES
316When using the
317.Ql key-=value
318syntax to remove items from existing values,
319the first character of the value is taken as the delimiter separating items
320.Pq usually Qo " " Qc or Qo , Qc .
321For example, in the following statement:
322.Pp
323.Dl Nm cloned_interfaces-=" gif0"
324.Pp
325the first character is a space, informing
326.Nm
327that existing values are to be considered separated by whitespace.
328If
329.Ql gif0
330is found in the existing value for
331.Va cloned_interfaces ,
332it is removed
333.Pq extra delimiters removed .
334.Pp
335For convenience, if the first character is alpha-numeric
336.Pq letters A-Z, a-z, or numbers 0-9 ,
337dot
338.Pq Li \&. ,
339or slash
340.Pq Li / ,
341.Nm
342uses the default setting of whitespace as separator.
343For example, the above and below statements are equivalent since
344.Dq gif0
345starts with an alpha-numeric character
346.Pq the letter Li g :
347.Bl -item -offset indent
348.It
349.Nm
350cloned_interfaces-=gif0
351.El
352.Pp
353Take the following sequence for example:
354.Bl -item -offset indent
355.It
356.Nm
357foo="bar baz" # start
358.It
359.Nm
360foo-=bar # `bar baz' -> `baz'
361.It
362.Nm
363foo-=baz # `baz' -> NULL
364.El
365.Pp
366.Nm
367removes all occurrences of all items provided
368and collapses extra delimiters between items.
369.Sh ENVIRONMENT
370The following environment variables are referenced by
371.Nm :
372.Bl -tag -width ".Ev RC_DEFAULTS"
373.It Ev RC_CONFS
374Override default
375.Ql rc_conf_files
376.Pq even if set to NULL .
377.It Ev RC_DEFAULTS
378Location of
379.Ql /etc/defaults/rc.conf
380file.
381.El
382.Sh DEPENDENCIES
383The following standard commands are required by
384.Nm :
385.Pp
386.Xr awk 1 ,
387.Xr cat 1 ,
388.Xr chmod 1 ,
389.Xr env 1 ,
390.Xr grep 1 ,
391.Xr mktemp 1 ,
392.Xr mv 1 ,
393.Xr rm 1 ,
394.Xr sh 1 ,
395.Xr stat 1 ,
396.Xr tail 1 ,
397.Xr chown 8 ,
398.Xr jls 8 ,
399and
400.Xr jexec 8 .
401.Sh FILES
402.Bl -tag -width ".Pa /etc/defaults/rc.conf" -compact
403.It Pa /etc/defaults/rc.conf
404.It Pa /etc/rc.conf
405.It Pa /etc/rc.conf.local
406.It Pa /etc/rc.conf.d/name
407.It Pa /etc/rc.conf.d/name/*
408.It Pa /usr/local/etc/rc.conf.d/name
409.It Pa /usr/local/etc/rc.conf.d/name/*
410.El
411.Sh EXAMPLES
412Below are some simple examples of how
413.Nm
414can be used to query certain values from the
415.Xr rc.conf 5
416collection of system configuration files:
417.Pp
418.Nm
419sshd_enable
420.Dl returns the value of $sshd_enable, usually YES or NO .
421.Pp
422.Nm
423defaultrouter
424.Dl returns IP address of default router Pq if configured .
425.Pp
426Working on other files, such as
427.Xr crontab 5 :
428.Pp
429.Nm
430-f /etc/crontab MAILTO
431.Dl returns the value of the MAILTO setting Pq if configured .
432.Pp
433Appending to existing values:
434.Pp
435.Nm
436\&cloned_interfaces+=gif0
437.Dl appends Qo gif0 Qc to $cloned_interfaces Pq see APPENDING VALUES .
438.Pp
439.Nm
440\&cloned_interfaces-=gif0
441.Dl removes Qo gif0 Qc from $cloned_interfaces Pq see SUBTRACTING VALUES .
442.Pp
443In addition to the above syntax,
444.Nm
445also supports inline
446.Xr sh 1
447PARAMETER expansion for changing the way values are reported, shown below:
448.Pp
449.Nm
450\&'hostname%%.*'
451.Dl returns $hostname up to (but not including) first `.' .
452.Pp
453.Nm
454\&'network_interfaces%%[$IFS]*'
455.Dl returns first word of $network_interfaces .
456.Pp
457.Nm
458\&'ntpdate_flags##*[$IFS]'
459.Dl returns last word of $ntpdate_flags (time server address) .
460.Pp
461.Nm
462usbd_flags-"default"
463.Dl returns $usbd_flags or "default" if unset or NULL .
464.Pp
465.Nm
466cloned_interfaces+"alternate"
467.Dl returns "alternate" if $cloned_interfaces is set .
468.Sh SEE ALSO
469.Xr rc.conf 5 ,
470.Xr jail 8 ,
471.Xr jexec 8 ,
472.Xr jls 8 ,
473.Xr rc 8 ,
474.Xr rc.subr 8 ,
475.Xr sysctl 8
476.Sh HISTORY
477A
478.Nm
479utility first appeared in
480.Fx 9.2 .
481.Sh AUTHORS
482.An Devin Teske Aq Mt dteske@FreeBSD.org
483.Sh THANKS TO
484Brandon Gooch, Enji Cooper, Julian Elischer, Pawel Jakub Dawidek,
485Cyrille Lefevre, Ross West, Stefan Esser, Marco Steinbach, Jilles Tjoelker,
486Allan Jude, and Lars Engels for suggestions, help, and testing.
487