xref: /openbsd-src/share/man/man8/rc.8 (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
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34.\"     @(#)rc.8	8.2 (Berkeley) 12/11/93
35.\"
36.Dd December 11, 1993
37.Dt RC 8
38.Os
39.Sh NAME
40.Nm rc
41.Nd command scripts for system startup
42.Sh SYNOPSIS
43.Nm /etc/rc
44.Nm /etc/rc.conf
45.Nm /etc/rc.local
46.Nm /etc/rc.securelevel
47.Nm /etc/netstart
48.Nm /etc/rc.shutdown
49.Sh DESCRIPTION
50.Nm rc
51is the command script that is invoked by
52.Xr init 8
53during an automatic reboot and after single user mode is exited;
54it performs system housekeeping chores and starts up system daemons.
55As well,
56.Nm rc
57is intricately tied to the
58.Nm netstart
59script, which runs commands and daemons pertaining to the network.
60The
61.Nm rc.securelevel
62and
63.Nm rc.local
64scripts hold commands which are pertinent only to a specific site.
65.Pp
66All four of these startup scripts are (or can be) controlled to some
67extent by variables defined in
68.Nm rc.conf ,
69which specifies which daemons and services are to be run.
70.Pp
71When an automatic reboot is in progress,
72.Nm rc
73is invoked with the argument
74.Em autoboot .
75The first portion of
76.Nm rc
77runs an
78.Xr fsck 8
79with option
80.Fl p
81to
82.Dq preen
83all disks of minor inconsistencies resulting
84from the last system shutdown and to check for serious inconsistencies
85caused by hardware or software failure.
86If this auto-check and repair succeeds, then the second part of
87.Nm rc
88is run.
89.Pp
90However, if the file
91.Pa /fastboot
92exists,
93.Xr fsck 8
94will not be invoked during this boot.
95This file is then removed so that it will be run on subsequent boots.
96.Pp
97The second part of
98.Nm rc ,
99which is run after an auto-reboot succeeds and also if
100.Nm rc
101is invoked when a single user shell terminates (see
102.Xr init 8 ) ,
103then asks
104.Nm rc.conf
105for configuration variables,
106mounts filesystems, starts system daemons,
107preserves editor files,
108clears the scratch directory
109.Pa /tmp ,
110and saves any possible core image that might have been
111generated as a result of a system crash, with
112.Xr savecore 8 .
113.Pp
114Before
115.Nm rc
116starts most system daemons,
117.Nm netstart
118is executed.
119.Nm netstart
120defines the machine's name, configures various  network interfaces
121and system features, initializes the routing table, and numerous
122other tasks.
123.Pp
124.Nm rc.securelevel
125is executed by
126.Nm rc
127to start daemons that must run before the security level changes.
128Following this,
129.Nm rc
130then sets the security level to the value specified in the
131.Va securelevel
132variable in that file.
133.Pp
134.Nm rc.local
135is executed towards the end of
136.Nm rc
137(it is not the very last as there are a few services that must be
138the started at the very end).
139Normally,
140.Nm rc.local
141contains commands and daemons that are not part of the
142stock installation.
143.Sh CONFIGURATION EXAMPLES
144The
145.Nm rc.conf
146file contains a series of Bourne-shell syntax assignments that
147are used to configure kernel configurations, network configuration,
148and various other system daemons.
149As described above, this file is sourced (using
150.Xr sh 1
151of course) by
152.Pa /etc/rc .
153Various comments in
154.Nm rc.conf
155make it clear what each variable does.  Refer to the specific man pages
156for each daemon to determine what that subsystem does.
157.Pp
158For example, the
159.Xr sendmail 8
160daemon is controlled by the line
161.Bd -literal
162    sendmail_flags=NO       # for normal use: sendmail_flags="-bd -q30m"
163.Ed
164.Pp
165This does not start
166.Xr sendmail 8
167at system startup.  But
168.Xr sendmail 8
169is started with the specified flags if the specification is modified to be
170.Bd -literal
171    sendmail_flags="-bd -q30m"      # for 'normal' use: sendmail_flags="-bd -q30m"
172.Ed
173.Sh EXTERNAL INFLUENCES
174Before
175.Xr init 8
176starts
177.Nm rc ,
178it sets the process priority, umask, and resource limits according to the
179.Dq daemon
180login class as described in
181.Pa /etc/login.conf .
182.Sh SEE ALSO
183.Xr login.conf 5 ,
184.Xr sysctl.conf 5 ,
185.Xr init 8 ,
186.Xr rc.conf 8 ,
187.Xr rc.shutdown 8 ,
188.Xr reboot 8 ,
189.Xr savecore 8
190.Sh HISTORY
191The
192.Nm
193command appeared in
194.Bx 4.0 .
195