xref: /openbsd-src/share/man/man8/rc.8 (revision 449248e97712db1636092e75c0e71056d017894a)
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30.\"     @(#)rc.8	8.2 (Berkeley) 12/11/93
31.\"
32.Dd $Mdocdate: June 30 2024 $
33.Dt RC 8
34.Os
35.Sh NAME
36.Nm rc ,
37.Nm rc.firsttime ,
38.Nm rc.local ,
39.Nm rc.securelevel
40.Nd command scripts for system startup
41.Sh DESCRIPTION
42.Nm rc
43is the command script that is invoked by
44.Xr init 8
45when the system starts up.
46It performs system housekeeping chores and starts up system daemons.
47Additionally,
48.Nm rc
49is intricately tied to the
50.Xr netstart 8
51script, which runs commands and daemons pertaining to the network.
52.Nm rc
53is also used to execute any
54.Xr rc.d 8
55scripts defined in
56.Xr rc.conf.local 8 .
57The
58.Nm rc.securelevel ,
59.Nm rc.firsttime ,
60and
61.Nm rc.local
62scripts hold commands which are pertinent only to a specific site.
63.Pp
64All of these startup scripts are controlled to some
65extent by variables defined in
66.Xr rc.conf 8 ,
67which specify which daemons and services to run.
68.Pp
69Before
70.Xr init 8
71starts
72.Nm rc ,
73it sets the process priority, umask, and resource limits according to the
74.Dq daemon
75login class as described in
76.Xr login.conf 5 .
77It then starts
78.Nm rc
79and attempts to execute the sequence of commands therein.
80.Pp
81The first part of
82.Nm rc
83runs an
84.Xr fsck 8
85with option
86.Fl p
87to
88.Dq preen
89all disks of minor inconsistencies resulting
90from the last system shutdown and to check for serious inconsistencies
91caused by hardware or software failure.
92If this auto-check and repair succeeds, then the second part of
93.Nm rc
94is run.
95However, if the file
96.Pa /fastboot
97exists,
98fsck will not be invoked.
99The file is then removed so that fsck will be run on subsequent boots.
100.Pp
101The second part of
102.Nm rc
103then asks
104.Xr rc.conf 8
105for configuration variables,
106mounts filesystems, saves
107.Xr dmesg 8
108output to the file
109.Pa /var/run/dmesg.boot ,
110starts system daemons,
111preserves editor files,
112clears the scratch directory
113.Pa /tmp ,
114uses
115.Xr savecore 8
116to save any possible core image that might have been
117generated as a result of a system crash,
118and relinks kernel objects in a random order.
119.Pp
120If at any point the boot script fails,
121.Xr init 8
122enters single-user mode,
123allowing the superuser a shell on the console.
124On exiting this mode,
125init again invokes
126.Nm rc ,
127but this time without performing the file system preen.
128.Pp
129Before
130.Nm rc
131starts most system daemons,
132.Xr netstart 8
133is executed.
134.Pp
135.Nm rc.securelevel
136is executed by
137.Nm rc
138to start daemons that must be run before the security level changes.
139Following this,
140.Nm rc
141then sets the security level to '1' if it wasn't set already by
142.Nm rc.securelevel .
143See
144.Xr securelevel 7
145for the effects of setting the security level.
146.Pp
147If
148.Nm rc.firsttime
149exists, it is executed once and then deleted.
150Any output is mailed to root.
151.Pp
152.Nm rc.local
153is executed towards the end of
154.Nm rc
155(it is not the very last as there are a few services that must be
156started at the very end).
157Normally,
158.Nm rc.local
159contains commands and daemons that are not part of the
160stock installation.
161.Sh FILES
162.Bl -tag -width "/etc/rc.securelevelXX" -compact
163.It Pa /etc/netstart
164Command script for network startup.
165.It Pa /etc/rc
166Command scripts for system startup.
167.It Pa /etc/rc.conf
168System daemon configuration database.
169.It Pa /etc/rc.conf.local
170Site specific daemon configuration database.
171.It Pa /etc/rc.d
172Directory to hold
173.Xr rc.d 8
174scripts.
175.It Pa /etc/rc.d/rc.subr
176Functions used by the
177.Xr rc.d 8
178scripts.
179.It Pa /etc/rc.firsttime
180Commands run on the first boot after creation.
181.It Pa /etc/rc.local
182Site specific command scripts for system startup.
183.It Pa /etc/rc.securelevel
184Commands run before the security level changes.
185.It Pa /etc/rc.shutdown
186Commands run at system shutdown.
187.It Pa /etc/examples/rc.*
188Examples of site specific scripts.
189.It Pa /fastboot
190Tells
191.Nm rc
192not to run
193.Xr fsck 8
194during the next boot.
195.It Pa /var/run/dmesg.boot
196Copy of
197.Xr dmesg 8
198saved by
199.Nm rc
200at boot time.
201.El
202.Sh SEE ALSO
203.Xr sysctl.conf 5 ,
204.Xr securelevel 7 ,
205.Xr init 8 ,
206.Xr netstart 8 ,
207.Xr rc.conf 8 ,
208.Xr rc.d 8 ,
209.Xr rc.shutdown 8 ,
210.Xr rcctl 8
211.Sh HISTORY
212The
213.Nm
214command appeared in
215.At v4 .
216