Changing scripts in /etc/rc2.d

Upon entering init state 2 (multiuser mode) from either a higher init state (3-6) or from single-user mode, init executes the /etc/rc2 script according to the instructions in /etc/inittab. The rc2 script sets certain environment variables and runs scripts in the /etc/rc2.d directory. Some of the scripts in rc2.d run scripts in subdirectories of the rc.d directory.

This section describes the scripts in the /etc/rc2.d directory that are run by rc2 and explains the steps for adding your own script. The rc2(ADM) manual page describes the other scripts that rc2 runs.

``/etc/rc2.d scripts'' gives a brief description of some of the scripts in /etc/rc2.d.

/etc/rc2.d scripts

Script	Description
S00MDAC	starts Mylex disk array monitor
P00SYSINIT	starts kernel message logger
S00VDISK	configures virtual disk arrays
I01MOUNTFSYS	mounts filesystems specified in /etc/default/filesys
P03RECOVERY	tidies up vi editing sessions after a crash
P04CLEAN	removes temporary files
P05RMTMPFILES	removes temporary files
P15HWDNLOAD	downloads hardware
P16KERNINIT	starts, process accounting, network, and other kernel initialization
P20sysetup	configures print system and generates /etc/systemid
P21perf	starts system accounting
S25pm	starts power management event routing and servicing daemon
S35dlpi	configures the network card driver interface
P70uucp	cleans up UUCP lock files
P75cron	starts cron daemon
S80lp	starts lpsched and net utilities
S85tcp	starts TCP/IP, name service, and routing
P86mmdf	starts mmdf deliver daemon
P86scologin	starts scologin
P87USRDAEMON	starts user daemons
P88USRDEFINE	executes user-definable commands after boot
S89hostmib	starts host MIB service
S89nfs	starts NFS service
P90RESERVED	mails fsck output saved during autoboot to root
S95calserver	starts calendar daemon
S95docview	starts DocView Apache server
S99apcssd	starts UPS port monitor

The /etc/rc2.d directory on your system may contain scripts other than the ones listed in the table. This is because during installation, many add-on programs insert their own daemon-initialization scripts in this directory. This directory may also include scripts that clean up the temporary or lock files for an add-on program.

You can write your own scripts to run when the system enters init state 2. For example, you can write a script that sets up a RAM disk or starts a network and add it to /etc/rc2.d.

The following factors should be considered when writing a system startup script to be placed in rc2.d :

• When going from a higher or lower init state to init state 2, files that begin with an ``S'', ``P'', or ``I'' are executed with the start option.

• When changing from a higher init state (3-9) to init state 2, scripts in rc2.d that begin with a ``K'' are executed with the stop option.

• Files that begin with characters other than ``S'', ``P'', ``I'', or ``K'' are ignored.

• Files are executed in order of their filenames sorted according to the ASCII collation sequence from their second character onwards (see rc2(ADM) and prc_sync(ADM) for more details). Scripts that start with ``S'' or ``I'' (or ``K'' for /etc/rc0.d shutdown scripts) are executed serially; those beginning with ``P'' are executed concurrently if they form a contiguous sequence between ``S'' or ``I'' (or ``K'') scripts. Processing of ``S'' or ``I'' (or ``K'') scripts does not start until all previous scripts have exited.

  ``Valid filename characters'' gives, in sort-sequence order (left to right), the ASCII characters that are valid for naming files.

  Valid filename characters

  #	%	+	,	-	.	0	1	2	3
  4	5	6	7	8	9	:	=	?	@
  A	B	C	D	E	F	G	H	I	J
  K	L	M	N	O	P	Q	R	S	T
  U	V	W	X	Y	Z	^	_	a	b
  c	d	e	f	g	h	i	j	k	l
  m	n	o	p	q	r	s	t	u	v
  w	x	y

• Your script may rely on the existence of services or daemons (such as network services, the cron daemon, or the print scheduler) started by other scripts. For example, if your script depends upon certain filesystems being mounted, make sure that you name your script so that it runs after the I01MOUNTFSYS script. (When you add a new filesystem with mkdev fs, the appropriate files are updated with the information necessary to mount the new filesystem when the system enters multiuser mode.)

1. Write a script that performs the desired function.

2. Test the script to make certain it behaves as expected. Be sure any environment variables used in the script are defined at startup.

3. Name the file so that it begins with the uppercase letter ``P'', ``S'', ``I'', or ``K'' followed by a two-digit number indicating the order in which it should be executed relative to the other files in the directory, and ends with a name that describes the script's function. For example, S80lp handles print service startup. It will be executed after any script that begins with S79, and before any that begins with S81. You must follow this naming convention to ensure that your script is executed at the proper time.

   Note that a set of scripts whose names start with P77, P78, and P79 will be executed concurrently. S80lp will not start until they have all exited.

4. Copy the script into the /etc/rc2.d directory so that it is executed by rc2 when the system enters (or leaves) multiuser mode.