xref: /freebsd/usr.sbin/sysrc/sysrc.8 (revision e91afc1cda50cbcb8fffa3f52cc0f8c595a392a3)
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25.\" $FreeBSD$
26.\"
27.Dd November 4, 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 Oo + Oc Ns = 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.
138In addition
139.Pq unlike Xr sysctl 8 ,
140.Ql name+=value
141is supported for appending values.
142.Pp
143However, while
144.Xr sysctl 8
145serves to query/modify MIBs in the entrant kernel,
146.Nm
147instead works on values in the system
148.Xr rc.conf 5
149configuration files.
150.Pp
151The list of system configuration files is configured in the file
152.Ql /etc/defaults/rc.conf
153within the variable
154.Ql rc_conf_files ,
155which by-default contains a space-separated list of pathnames.
156On all FreeBSD
157systems, this defaults to the value "/etc/rc.conf /etc/rc.conf.local".
158Each
159pathname is sourced in-order upon startup.
160It is in the same fashion that
161.Nm
162sources the configuration files before returning the value of the given
163variable.
164.Pp
165When supplied a variable name,
166.Nm
167will return the value of the variable.
168If the variable does not appear in any
169of the configured
170.Ql rc_conf_files ,
171an error is printed and error status is returned.
172.Pp
173When changing values of a given variable, it does not matter if the variable
174appears in any of the
175.Ql rc_conf_files
176or not.
177If the variable does not appear in any of the files, it is appended to
178the end of the first pathname in the
179.Ql rc_conf_files
180variable.
181Otherwise,
182.Nm
183will replace only the last-occurrence in the last-file found to contain the
184variable.
185This gets the value to take effect next boot without heavily
186modifying these integral files (yet taking care not to allow the file to
187grow unwieldy should
188.Nm
189be called repeatedly).
190.Sh ENVIRONMENT
191The following environment variables are referenced by
192.Nm :
193.Bl -tag -width ".Ev RC_DEFAULTS"
194.It Ev RC_CONFS
195Override default
196.Ql rc_conf_files
197.Pq even if set to NULL .
198.It Ev RC_DEFAULTS
199Location of
200.Ql /etc/defaults/rc.conf
201file.
202.El
203.Sh DEPENDENCIES
204The following standard commands are required by
205.Nm :
206.Pp
207.Xr awk 1 ,
208.Xr cat 1 ,
209.Xr chmod 1 ,
210.Xr env 1 ,
211.Xr grep 1 ,
212.Xr jls 1 ,
213.Xr mktemp 1 ,
214.Xr mv 1 ,
215.Xr rm 1 ,
216.Xr sh 1 ,
217.Xr stat 1 ,
218.Xr tail 1 ,
219.Xr chown 8
220and
221.Xr jexec 8 .
222.Sh FILES
223.Bl -tag -width ".Pa /etc/defaults/rc.conf" -compact
224.It Pa /etc/defaults/rc.conf
225.It Pa /etc/rc.conf
226.It Pa /etc/rc.conf.local
227.El
228.Sh EXAMPLES
229Below are some simple examples of how
230.Nm
231can be used to query certain values from the
232.Xr rc.conf 5
233collection of system configuration files:
234.Pp
235.Nm
236sshd_enable
237.Dl returns the value of $sshd_enable, usually YES or NO .
238.Pp
239.Nm
240defaultrouter
241.Dl returns IP address of default router Pq if configured .
242.Pp
243Working on other files, such as
244.Xr crontab 5 :
245.Pp
246.Nm
247-f /etc/crontab MAILTO
248.Dl returns the value of the MAILTO setting Pq if configured .
249.Pp
250Appending to existing values:
251.Pp
252.Nm
253\&cloned_interfaces+=" gif0"
254.Dl appends Qo \ gif0 Qc to $cloned_interfaces .
255.Pp
256In addition to the above syntax,
257.Nm
258also supports inline
259.Xr sh 1
260PARAMETER expansion for changing the way values are reported, shown below:
261.Pp
262.Nm
263\&'hostname%%.*'
264.Dl returns $hostname up to (but not including) first `.' .
265.Pp
266.Nm
267\&'network_interfaces%%[$IFS]*'
268.Dl returns first word of $network_interfaces .
269.Pp
270.Nm
271\&'ntpdate_flags##*[$IFS]'
272.Dl returns last word of $ntpdate_flags (time server address) .
273.Pp
274.Nm
275usbd_flags-"default"
276.Dl returns $usbd_flags or "default" if unset or NULL .
277.Pp
278.Nm
279cloned_interfaces+"alternate"
280.Dl returns "alternate" if $cloned_interfaces is set .
281.Pp
282.Nm
283\&'#kern_securelevel'
284.Dl returns length in characters of $kern_securelevel .
285.Pp
286.Nm
287\&'hostname?'
288.Dl returns NULL and error status 2 if $hostname is unset Pq or if set, returns the value of $hostname with no error status .
289.Pp
290.Nm
291\&'hostname:?'
292.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 .
293.Sh LIMITATIONS
294The
295.Nm
296utility presently does not support the
297.Ql rc.conf.d
298collection of system configuration files
299.Pq which requires a service name to be known during execution .
300.Pp
301This will be corrected by a future enhancement.
302.Sh SEE ALSO
303.Xr jls 1 ,
304.Xr rc.conf 5 ,
305.Xr jail 8 ,
306.Xr jexec 8 ,
307.Xr rc 8 ,
308.Xr sysctl 8
309.Sh HISTORY
310A
311.Nm
312utility first appeared in
313.Fx 9.2 .
314.Sh AUTHORS
315.An Devin Teske Aq Mt dteske@FreeBSD.org
316.Sh THANKS TO
317Brandon Gooch, Garrett Cooper, Julian Elischer, Pawel Jakub Dawidek,
318Cyrille Lefevre, Ross West, Stefan Esser, Marco Steinbach, Jilles Tjoelker,
319Allan Jude, and Lars Engels for suggestions, help, and testing.
320