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32 .Nd safely edit system rc files
37 .Op Fl j Ar jail | Fl R Ar dir
38 .Ar name Ns Op Ns Oo +|- Oc Ns = Ns Ar value
43 .Op Fl j Ar jail | Fl R Ar dir
50 variables from the collection of system rc files and allows processes with
51 appropriate privilege to change values in a safe and effective manner.
53 The following options are available:
54 .Bl -tag -width indent+
56 Dump a list of all non-default configuration variables.
58 Dump a list of all configuration variables
62 For querying, return success if all requested variables are set
64 otherwise return error status.
65 For assignments, return success if no changes are required, otherwise failure.
68 prints a message stating whether variables are set and/or changes are required.
70 Print a description of the given variable.
72 Show default value(s) only (this is the same as setting RC_CONFS to NULL or
73 passing `-f' with a NULL file-argument).
75 Print query results as
78 .Pq for example, Ql var=value .
85 Operate on the specified file(s) instead of the files obtained by reading the
90 This option can be specified multiple times for additional files.
94 file each directive is in.
96 Print a short usage message to stderr and exit.
98 Print a full usage statement to stderr and exit.
100 Ignore unknown variables.
107 .Pq overrides So Fl R Ar dir Sc ; requires Xr jexec 8 .
109 Show only variable values, not their names.
111 Show only variable names, not their values.
114 Disable verbose and hide certain errors.
116 Operate within the root directory
122 Print the pathname of the specific
124 file where the directive was found.
126 Print version information to stdout and exit.
128 Remove variable(s) from specified file(s).
131 This utility has a similar syntax to
133 It shares the `-e' and `-n' options
135 and also has the same
137 syntax for making queries/assignments.
139 .Pq but unlike Xr sysctl 8 ,
141 is supported for adding items to values
142 .Pq see APPENDING VALUES
145 is supported for removing items from values
146 .Pq see SUBTRACTING VALUES .
150 serves to query/modify MIBs in the entrant kernel,
152 instead works on values in the system
156 The list of system configuration files is configured in the file
157 .Ql /etc/defaults/rc.conf
160 which by-default contains a space-separated list of pathnames.
162 systems, this defaults to the value "/etc/rc.conf /etc/rc.conf.local".
164 pathname is sourced in-order upon startup.
165 It is in the same fashion that
167 sources the configuration files before returning the value of the given
170 When supplied a variable name,
172 will return the value of the variable.
173 If the variable does not appear in any
176 an error is printed and error status is returned.
178 When changing values of a given variable, it does not matter if the variable
179 appears in any of the
182 If the variable does not appear in any of the files, it is appended to
183 the end of the first pathname in the
188 will replace only the last-occurrence in the last-file found to contain the
190 This gets the value to take effect next boot without heavily
191 modifying these integral files (yet taking care not to allow the file to
194 be called repeatedly).
198 syntax to add items to existing values,
199 the first character of the value is taken as the delimiter separating items
200 .Pq usually Qo \ Qc or Qo , Qc .
201 For example, in the following statement:
202 .Bl -item -offset indent
205 cloned_interfaces+=" gif0"
208 the first character is a space, informing
210 that existing values are to be considered separated by whitespace.
213 is not found in the existing value for
214 .Va cloned_interfaces ,
216 .Pq with delimiter only if existing value is non-NULL .
218 For convenience, if the first character is alpha-numeric
219 .Pq letters A-Z, a-z, or numbers 0-9 ,
221 uses the default setting of whitespace as separator.
222 For example, the above and below statements are equivalent since
224 starts with an alpha-numeric character
225 .Pq the letter Li g :
226 .Bl -item -offset indent
229 cloned_interfaces+=gif0
232 Take the following sequence for example:
233 .Bl -item -offset indent
236 cloned_interfaces= # start with NULL
239 cloned_interfaces+=gif0
240 .Dl # NULL -> `gif0' Pq NB: no preceding delimiter
243 cloned_interfaces+=gif0 # no change
246 cloned_interfaces+="tun0 gif0"
247 .Dl # `gif0' -> `gif0 tun0' Pq NB: no duplication
251 prevents the same value from being added if already there.
252 .Sh SUBTRACTING VALUES
255 syntax to remove items from existing values,
256 the first character of the value is taken as the delimiter separating items
257 .Pq usually Qo \ Qc or Qo , Qc .
258 For example, in the following statement:
260 .Dl Nm cloned_interfaces-=" gif0"
262 the first character is a space, informing
264 that existing values are to be considered separated by whitespace.
267 is found in the existing value for
268 .Va cloned_interfaces ,
270 .Pq extra delimiters removed .
272 For convenience, if the first character is alpha-numeric
273 .Pq letters A-Z, a-z, or numbers 0-9 ,
275 uses the default setting of whitespace as separator.
276 For example, the above and below statements are equivalent since
278 starts with an alpha-numeric character
279 .Pq the letter Li g :
280 .Bl -item -offset indent
283 cloned_interfaces-=gif0
286 Take the following sequence for example:
287 .Bl -item -offset indent
290 foo="bar baz" # start
293 foo-=bar # `bar baz' -> `baz'
296 foo-=baz # `baz' -> NULL
300 removes all occurrences of all items provided
301 and collapses extra delimiters between items.
303 The following environment variables are referenced by
305 .Bl -tag -width ".Ev RC_DEFAULTS"
309 .Pq even if set to NULL .
312 .Ql /etc/defaults/rc.conf
316 The following standard commands are required by
335 .Bl -tag -width ".Pa /etc/defaults/rc.conf" -compact
336 .It Pa /etc/defaults/rc.conf
338 .It Pa /etc/rc.conf.local
341 Below are some simple examples of how
343 can be used to query certain values from the
345 collection of system configuration files:
349 .Dl returns the value of $sshd_enable, usually YES or NO .
353 .Dl returns IP address of default router Pq if configured .
355 Working on other files, such as
359 -f /etc/crontab MAILTO
360 .Dl returns the value of the MAILTO setting Pq if configured .
362 Appending to existing values:
365 \&cloned_interfaces+=gif0
366 .Dl appends Qo gif0 Qc to $cloned_interfaces Pq see APPENDING VALUES .
369 \&cloned_interfaces-=gif0
370 .Dl removes Qo gif0 Qc from $cloned_interfaces Pq see SUBTRACTING VALUES .
372 In addition to the above syntax,
376 PARAMETER expansion for changing the way values are reported, shown below:
380 .Dl returns $hostname up to (but not including) first `.' .
383 \&'network_interfaces%%[$IFS]*'
384 .Dl returns first word of $network_interfaces .
387 \&'ntpdate_flags##*[$IFS]'
388 .Dl returns last word of $ntpdate_flags (time server address) .
392 .Dl returns $usbd_flags or "default" if unset or NULL .
395 cloned_interfaces+"alternate"
396 .Dl returns "alternate" if $cloned_interfaces is set .
407 utility first appeared in
410 .An Devin Teske Aq dteske@FreeBSD.org
412 Brandon Gooch, Garrett Cooper, Julian Elischer, Pawel Jakub Dawidek,
413 Cyrille Lefevre, Ross West, Stefan Esser, Marco Steinbach, Jilles Tjoelker,
414 Allan Jude, and Lars Engels for suggestions, help, and testing.