xref: /freebsd/usr.sbin/sysrc/sysrc.8 (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1.\" Copyright (c) 2011-2014 Devin Teske
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\"
13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23.\" SUCH DAMAGE.
24.\"
25.\" $FreeBSD$
26.\"
27.Dd Jul 18, 2014
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 cdDeFhinNqvx
36.Op Fl f Ar file
37.Op Fl j Ar jail | Fl R Ar dir
38.Ar name Ns Op = Ns Ar value
39.Ar ...
40.Nm
41.Op Fl cdDeFhinNqvx
42.Op Fl f Ar file
43.Op Fl j Ar jail | Fl R Ar dir
44.Fl a | A
45.Sh DESCRIPTION
46The
47.Nm
48utility retrieves
49.Xr rc.conf 5
50variables from the collection of system rc files and allows processes with
51appropriate privilege to change values in a safe and effective manner.
52.Pp
53The following options are available:
54.Bl -tag -width indent+
55.It Fl a
56Dump a list of all non-default configuration variables.
57.It Fl A
58Dump a list of all configuration variables
59.Pq incl. defaults .
60.It Fl c
61Check only.
62For querying, return success if all requested variables are set
63.Pq even if NULL ,
64otherwise return error status.
65For assignments, return success if no changes are required, otherwise failure.
66If verbose
67.Pq see Dq Fl v
68prints a message stating whether variables are set and/or changes are required.
69.It Fl d
70Print a description of the given variable.
71.It Fl D
72Show default value(s) only (this is the same as setting RC_CONFS to NULL or
73passing `-f' with a NULL file-argument).
74.It Fl e
75Print query results as
76.Xr sh 1
77compatible syntax
78.Pq for example, Ql var=value .
79Ignored if either
80.Ql Fl n
81or
82.Ql Fl F
83is specified.
84.It Fl f Ar file
85Operate on the specified file(s) instead of the files obtained by reading the
86.Sq rc_conf_files
87entry in the
88.Ev RC_DEFAULTS
89file.
90This option can be specified multiple times for additional files.
91.It Fl F
92Show only the last
93.Xr rc.conf 5
94file each directive is in.
95.It Fl h
96Print a short usage message to stderr and exit.
97.It Fl -help
98Print a full usage statement to stderr and exit.
99.It Fl i
100Ignore unknown variables.
101.It Fl j Ar jail
102The
103.Ar jid
104or name of the
105.Ar jail
106to operate within
107.Pq overrides So Fl R Ar dir Sc ; requires Xr jexec 8 .
108.It Fl n
109Show only variable values, not their names.
110.It Fl N
111Show only variable names, not their values.
112.It Fl q
113Quiet.
114Disable verbose and hide certain errors.
115.It Fl R Ar dir
116Operate within the root directory
117.Sq Ar dir
118rather than
119.Sq / .
120.It Fl v
121Verbose.
122Print the pathname of the specific
123.Xr rc.conf 5
124file where the directive was found.
125.It Fl -version
126Print version information to stdout and exit.
127.It Fl x
128Remove variable(s) from specified file(s).
129.El
130.Pp
131This utility has a similar syntax to
132.Xr sysctl 8 .
133It shares the `-e' and `-n' options
134.Pq detailed above
135and also has the same
136.Ql name[=value]
137syntax for making queries/assignments.
138.Pp
139However, while
140.Xr sysctl 8
141serves to query/modify MIBs in the entrant kernel,
142.Nm
143instead works on values in the system
144.Xr rc.conf 5
145configuration files.
146.Pp
147The list of system configuration files is configured in the file
148.Ql /etc/defaults/rc.conf
149within the variable
150.Ql rc_conf_files ,
151which by-default contains a space-separated list of pathnames.
152On all FreeBSD
153systems, this defaults to the value "/etc/rc.conf /etc/rc.conf.local".
154Each
155pathname is sourced in-order upon startup.
156It is in the same fashion that
157.Nm
158sources the configuration files before returning the value of the given
159variable.
160.Pp
161When supplied a variable name,
162.Nm
163will return the value of the variable.
164If the variable does not appear in any
165of the configured
166.Ql rc_conf_files ,
167an error is printed and error status is returned.
168.Pp
169When changing values of a given variable, it does not matter if the variable
170appears in any of the
171.Ql rc_conf_files
172or not.
173If the variable does not appear in any of the files, it is appended to
174the end of the first pathname in the
175.Ql rc_conf_files
176variable.
177Otherwise,
178.Nm
179will replace only the last-occurrence in the last-file found to contain the
180variable.
181This gets the value to take effect next boot without heavily
182modifying these integral files (yet taking care not to allow the file to
183grow unwieldy should
184.Nm
185be called repeatedly).
186.Sh ENVIRONMENT
187The following environment variables are referenced by
188.Nm :
189.Bl -tag -width ".Ev RC_DEFAULTS"
190.It Ev RC_CONFS
191Override default
192.Ql rc_conf_files
193.Pq even if set to NULL .
194.It Ev RC_DEFAULTS
195Location of
196.Ql /etc/defaults/rc.conf
197file.
198.El
199.Sh DEPENDENCIES
200The following standard commands are required by
201.Nm :
202.Pp
203.Xr awk 1 ,
204.Xr cat 1 ,
205.Xr chmod 1 ,
206.Xr env 1 ,
207.Xr grep 1 ,
208.Xr jls 1 ,
209.Xr mktemp 1 ,
210.Xr mv 1 ,
211.Xr rm 1 ,
212.Xr sh 1 ,
213.Xr stat 1 ,
214.Xr tail 1 ,
215.Xr chown 8
216and
217.Xr jexec 8 .
218.Sh FILES
219.Bl -tag -width ".Pa /etc/defaults/rc.conf" -compact
220.It Pa /etc/defaults/rc.conf
221.It Pa /etc/rc.conf
222.It Pa /etc/rc.conf.local
223.El
224.Sh EXAMPLES
225Below are some simple examples of how
226.Nm
227can be used to query certain values from the
228.Xr rc.conf 5
229collection of system configuration files:
230.Pp
231.Nm
232sshd_enable
233.Dl returns the value of $sshd_enable, usually YES or NO .
234.Pp
235.Nm
236defaultrouter
237.Dl returns IP address of default router Pq if configured .
238.Pp
239Working on other files, such as
240.Xr crontab 5 :
241.Pp
242.Nm
243-f /etc/crontab MAILTO
244.Dl returns the value of the MAILTO setting Pq if configured .
245.Pp
246In addition to the above syntax,
247.Nm
248also supports inline
249.Xr sh 1
250PARAMETER expansion for changing the way values are reported, shown below:
251.Pp
252.Nm
253\&'hostname%%.*'
254.Dl returns $hostname up to (but not including) first `.' .
255.Pp
256.Nm
257\&'network_interfaces%%[$IFS]*'
258.Dl returns first word of $network_interfaces .
259.Pp
260.Nm
261\&'ntpdate_flags##*[$IFS]'
262.Dl returns last word of $ntpdate_flags (time server address) .
263.Pp
264.Nm
265usbd_flags-"default"
266.Dl returns $usbd_flags or "default" if unset or NULL .
267.Pp
268.Nm
269cloned_interfaces+"alternate"
270.Dl returns "alternate" if $cloned_interfaces is set .
271.Pp
272.Nm
273\&'#kern_securelevel'
274.Dl returns length in characters of $kern_securelevel .
275.Pp
276.Nm
277\&'hostname?'
278.Dl returns NULL and error status 2 if $hostname is unset Pq or if set, returns the value of $hostname with no error status .
279.Pp
280.Nm
281\&'hostname:?'
282.Dl returns NULL and error status 2 if $hostname is unset or NULL Pq or if set and non-NULL, returns value without error status .
283.Sh LIMITATIONS
284The
285.Nm
286utility presently does not support the
287.Ql rc.conf.d
288collection of system configuration files
289.Pq which requires a service name to be known during execution .
290.Pp
291This will be corrected by a future enhancement.
292.Sh SEE ALSO
293.Xr jls 1 ,
294.Xr rc.conf 5 ,
295.Xr jail 8 ,
296.Xr jexec 8 ,
297.Xr rc 8 ,
298.Xr sysctl 8
299.Sh HISTORY
300A
301.Nm
302utility first appeared in
303.Fx 9.2 .
304.Sh AUTHORS
305.An Devin Teske Aq Mt dteske@FreeBSD.org
306.Sh THANKS TO
307Brandon Gooch, Garrett Cooper, Julian Elischer, Pawel Jakub Dawidek,
308Cyrille Lefevre, Ross West, Stefan Esser, Marco Steinbach, Jilles Tjoelker,
309Allan Jude, and Lars Engels for suggestions, help, and testing.
310