Ê×ÏÈÎÒÃÇÏȽ²Ò»ÏÂΪʲôÊÇ sysv init 2.6:
ÒòΪºÜ¶à distributions ÓÃÁËÓÐÎÊÌâµÄ 2.5x °æ......
ËùÒÔÎÒÃÇÒÔ Linux Ϊƽ̨, ½² 2.6 µÄ¡£

ÕâÑù¿ª³¡°×ºÃÏñ¹Ö¹ÖµÄ, ÏȲ»¹ÜËü¡£

Ò»°ãÀ´Ëµ, ϵͳÔÚÅÜÍê kernel bootstrapping ºó, ¾ÍÈ¥ÔËÐÐ init
Õâ¸ö¡ºÍòprocessÖ®¸¸¡», ÓÐÁËËü, ²ÅÄÜ¿ªÊ¼ÉúСº¢......
ÁíÍâ Linux ÓÐÁ½¸ö kernel ÀàµÄ process Ò²¿ªÊ¼ÅÜÁËÆðÀ´,
Ò»¸öÊÇ kflushd, ÁíÒ»¸öÊÇ kswapd:

* process ID 1: init
* process ID 2: kflushd
* process ID 3: kswapd

Ö»ÓÐÕâ¸ö init ÊÇÍêÈ«ÊôÓÚ user ÀàµÄ process, ºóÁ½ÕßÊÇ kernel
¼Ù½è process Ö®Ãû¹ÒÔÚ½ø³ÌÉÏ¡£

init Ò»¿ªÊ¼¾ÍÈ¥¶Á /etc/inittab, Õâ¸ö inittab ÖжÔÓÚ¸÷¸ö
runlevel ÒªÅÜÄÄЩ rc »ò spawn ³öʲôÓкÜÇå³þµÄÉ趨¡£

--------[/etc/inittab ]---------------------------------

# /etc/inittab: init(8) configuration.
# $Id: inittab,v 1.4 1996/03/10 11:47:55 miquels Exp $

# The default runlevel, ÎÒÃÇÉèΪ 3; runlevel µÄ¸ÅÄîÎÒÃǵȻá¶ùÌá¡£
id:3:initdefault:

# ¿ª»úµÄ system configuration/initialization script.
# This is run first except when booting in emergency (-b) mode.
si::sysinit:/etc/init.d/boot

# What to do in single-user mode. sulogin ¼´Îª Single User LOGIN.
~:S:wait:/sbin/sulogin

# /etc/init.d executes the S and K scripts upon change
# of runlevel. ÆäÖÐ /etc/init.d/rc ÊÇÒ»¸ö shell script,
# ºóÃæµÄ 0~6 ²ÎÊý±íʾҪÅܸà runlevel ËùÓ¦ÅܵÄÉ趨 script.
# Runlevel 0 is halt.
# Runlevel 1 is single-user.
# Runlevels 2-5 are multi-user.
# Runlevel 6 is reboot.

l0:0:wait:/etc/init.d/rc 0
l1:1:wait:/etc/init.d/rc 1
l2:2:wait:/etc/init.d/rc 2
l3:3:wait:/etc/init.d/rc 3
l4:4:wait:/etc/init.d/rc 4
l5:5:wait:/etc/init.d/rc 5
l6:6:wait:/etc/init.d/rc 6

# µ± CTRL-ALT-DEL °´ÏÂÈ¥ÁË, ¸Ã×öʲô£¿Ò»°ã¶¼ÊÇ shutdown -r now
ca:12345:ctrlaltdel:/sbin/shutdown -t1 -r now
#-t1 Òâ˼ÊÇÏȵȸöÒ»ÃëºÃÁË

# Action on special keypress (ALT-UpArrow). Õâ¸öÎÒÔÝʱ²é²»µ½, ±§Ç¸¡£
kb::kbrequest:/bin/echo "Keyboard Request--edit /etc/inittab to let this work."

# What to do when the power fails/returns. Õâ¸öÎÒÍíÒ»µã½² (ÓÐ¹Ø UPS µÄ²¿·Ý)
pf::powerwait:/etc/init.d/genpowerfail start
#pn::powerfailnow:/etc/init.d/genpowerfail now
po::powerokwait:/etc/init.d/genpowerfail stop
#pg::powerokwait:/etc/init.d/genpowerfail stop

# /sbin/getty invocations for the runlevels.
# ^^^^^^^^^^^¿ª console ³öÀ´ÁË¡£
# The "id" field MUST be the same as the last
# characters of the device (after "tty").
# ÀýÈçÔÚ runlevel==3 ʱ, »áÓÐÁù¸ö virtual console (tty1~tty6)
# Format:
# :::
1:2345:respawn:/sbin/agetty 19200 tty1
2:23:respawn:/sbin/agetty 19200 tty2
3:23:respawn:/sbin/agetty 19200 tty3
4:23:respawn:/sbin/agetty 19200 tty4
5:23:respawn:/sbin/agetty 19200 tty5
6:23:respawn:/sbin/agetty 19200 tty6

----------[End of /etc/inittab]---------------------------------

ÉÏÃæµÄÉ趨, ÁîϵͳÔÚÒ»ÅÜÍê kernel bootstrapping ºó, ¾ÍÈ¥Ö´
ÐÐ /etc/init.d/boot Õâ¸ö shell script, Èç¹ûûʲôÎÊÌâ, ¾Í
½øÈë default runlevel, runlevel ÔÚ sysv ͨ³£ÊÇÓÐÈçÏÂÒâÒå:

0: halt (Ö»ÓÐ shutdown, ²» reboot ÁË)
1: Single-user
2: Multi-user
3: Multi-user & °Ñ network resource export ³öÀ´
4: ³ýÁËÓÐ Multi-user & export network resource, Ò»°ãÀ´½²ÊÇÁô¸ø xdm
5: ²»Ì«Óõ½ÁË.
6: reboot (shutdown ºó»á reboot)

£¨×¢£ºÔÚRedhatÖÐLevel4ÓëLevel5µÄ¶¨ÒåÓëSlackwareÏà·´£©

ÆäÖÐ 2-5 ¶¼ÊÇ multi-user µÄ runlevel, ͨ³£ runlevel(2~5)
Ô½¸ß, ËùÌṩµÄ·þÎñÒ²¾ÍÔ½¶à¡£µ±ÏµÍ³×ÊÔ´ÓÐËù±ä¶¯ (ÀýÈçµçÁ¦)
ʱ, ÎÒÃÇ¿ÉÒÔÓà telinit È¥¸æÖª init Òª±ä»» runlevel (ÀýÈç
Ô­À´ÊÇ runlevel=3, Óà telinit 2 ʹ runlevel ½µÎª 2), Õâ
Ñù×Ó¿ÉÒԹصôһЩÍøÂç×ÊÔ´·þÎñ; »òÀýÈç telinit S Óë telinit 1
¶¼Êǵ½ Single-user mode (µ«Ç°Õß²»Í¬µÄÊÇ, telinit S ¸ù±¾
¾ÍÖ±½ÓÔÚ /dev/console ÉÏÖ´ÐÐÒ»¸ö /bin/sh ¸øÄãÓÃ; ºóÕß»á
È¥Ö´ÐÐ /etc/init.d/rc 1 Õâ¸öÖ¸Áî); telinit 6 ¾ÍµÈÓÚ reboot.

OK, ÓÐÎÊÌâÇëÏÈÌá³öÀ´¡£

ÏÂÃæÎÒÃÇÒª½²µ½µÄÊÇ /etc/init.d/boot Õâ¸ö script Ó¦¸Ã×öЩ
ʲô, ²ÅÊÇÎÒÃÇÒªµÄ¡£
 

ÔÙÀ´ÎÒÃǽ²Ò»Ï /etc/init.d/boot Õâ¸ö script.

¼ÈÈ» kernel bootstrapping Íê, ÎÒÃǾÍÒª¿ªÊ¼×öһЩ
ºÜ»ù±¾µÄ¼ì²é¡¢É趨, ÒÔ¼°×öһЩ¡º×¼±¸¹¤×÷¡»¡£

ÔÚ kernel bootstrapping ºó, ÔÚ mount root as read-only
Ç°»áÏÈ×öһЩ¹¤×÷, ÒÔ Linux ΪÀý:

* ÏÈÉ趨Õâ¸ö script µÄ PATH ¼° umask
* µ÷Èë kerneld Õâ¸ö daemon (Õâ¸öºÍ kernel modules ÓйØ, ºóÃæÔÙ½²)
* mdadd -ar, °Ñ md device ÅÜÆðÀ´ (ÕâÒ²ÊǺóÃæÔÙ½²)
* swapon -a, °ÑËùÓÐµÄ swap partition ´ò¿ªÀ´ÓÃ.
* µ÷Èë update (bdflush) Õâ¸ö daemon

kerneld ÊÇ Linux kernel 1.3.xx ÓÐÁË modules »¯ºó,
Ò»¸ö»á×Ô¶¯µ÷ modules ½ø kernel µÄ daemon, Ò²»á°Ñ
¾­Ò»¶Îʱ¼äºó²»ÔøÓõ½µÄ modules °Î³ö kernel¡£ ÓйØ
modules µÄ¸ÅÄî, ÎÒÃǵȵ½ kernel µÄ½éÉÜÔÙ̸ÏêϸµÄ¡£

md device ÊÇ Linux kernel 1.3.69 ºóмÓÈëµÄ¹¦ÄÜ,
Ëü¿ÉÒÔ°ÑÁ½¸öÒÔÉ쵀 partition ºÏ³ÉÒ»¸ö´óµÄ md device
Ö®ºó, Ö±½Ó×ö³ö file system »ò swap space, ¶øÇÒ¿ÉÒÔ
¡º½»´íµØ¡»°²ÅÅ block λÖÃ, Õâ¾ÍÏñ RAID-0 Ò»Ñù, ËùÒÔ
²»µ«¿ÉÒÔ½«Ò»¶ÑСµÄ partition ºÏ³É´óµÄÀ´ÓÃ, Ò²¿ÉÒÔÌá
¸ßËٶȡ£

update (bdflush) Õâ¸ö daemon ÊÇÿ¸ôÒ»¶Îʱ¼ä (Ô¤ÉèÖµ
ÊÇ 5 Ãë) ¾Í°Ñ 'dirty blocks' flush »Ø disk ÖÐ. Õâ¸ö
Ò»¶¨ÒªÔÚÅÜ fsck µÈÖ÷ÒªµÄ I/O ¶¯×÷Ç°¾ÍÏȵ÷ÈëµÄÁË¡£

ºÃ, ×î»ù±¾µÄ×¼±¸Íê±Ïºó, ÎÒÃǾÍÒªÏÈÀ´ fsck ÁË¡£
Ê×ÏÈÊÇ°Ñ¡º¸ù¡»mount ÆðÀ´, ¶øÇÒÊÇ read-only:

* mount -n -o remount,ro /

ÆäÖÐ -n µÄ²ÎÊýÊDz»°Ñ mount µÄ¶¯×÷дÈë /etc/mtab ÖÐ,
ÒòΪÏÖÔÚÊÇ°Ñ '/' mount ³É read-only, ¸ù±¾²»ÄÜдÈë¡£
È»ºóÎÒÃÇ¿ªÊ¼ fsck:

* fsck -A -a

²ÎÊý -A ÊÇ¶Ô /etc/fstab ÖеĶ«Î÷È«²¿ check Ò»´Î, -a
µÄ²ÎÊýÊÇÖ¸ auto-repair. ÔÚ¼ì²éºóÈç¹ûÓж«Î÷ʵÔÚÊDz»ÄÜ
ÐÞºÃ, ¾Í»áÖ´ÐÐ sulogin, È»ºó reboot. Èç¹ûÕý³£, ÄǾÍ
°Ñ '/' remount ³É read-write:

* mount -n -o remount,rw /

ÒòΪºóÃ滹»á mount -a, ËùÒÔÕâ´ÎÎÒÃÇ»¹ÊÇÓÃÁË -n ²ÎÊý¡£

½ÓÏÂÀ´ÊÇÅÜһЩ¡ºµ± '/' ¿ÉÒÔ write ÁË¡»Ö®ºó, Á¢¿ÌÒª×öµÄ
ÊÂ:

* ÅÜ modules µÄÉ趨
* °ÑһЩ /etc ¼° / ϵIJ¿·ÖÎļþÇå³ý
* ¸üРpsdatabase

·¶ÀýÈçÏÂ:

----------[/etc/init.d/boot ²¿·ÝÄÚÈÝ]-------------------------
# Load the appropriate modules.
if [ -x /etc/init.d/modules ]
then
/etc/init.d/modules
fi

# Remove /etc/mtab*, /etc/rmtab, /etc/nologin and /fastboot.
rm -f /etc/mtab* /etc/nologin /fastboot /etc/rmtab

# update /etc/psdatabase
psupdate 2> /dev/null
# or
#ps -U 2> /dev/null
---------[·¶Àý½áÊø]--------------------------------------------

ÉÏÃæµÄ¶«Î÷, ÎÒÏë´ó¼Ò´ó¸Å¶¼¿´µÃ¶®......

ºÃ, ÔÙÀ´¾ÍÊÇ°ÑËùÓÐµÄ local partitions ¶¼¸øËü mount ÆðÀ´.

* mount -avt nonfs

ÄÇΪºÎÊÇ -t nonfs ÄØ£¿ ºÜ¼òµ¥, ÒòΪÎÒÃÇ»¹Ã»¿ªÊ¼É趨 network.
È»ºó, Èç¹ûÎÒÃÇÓÐһЩ swap file ÊÇÔÚ mount -a ºó²Å³öÏÖµÄ,
Õâʱ¾ÍÒªÔÙÅÜÒ»´Î swapon:

* swapon -a 2>/dev/null

²Å»á°Ñ swap file ¿ªÀ´Óá£
OK, È»ºóÉ趨ÍøÂç (ÕâʱÊÇÈ¥½ÐÓÃÒ»¸ö¶ÀÁ¢µÄ script,
Èç¹ûÕâ¸ö script ²»´æÔÚ, ÎÒÃǾÍÎÞ·¨É趨 network)
¼°Ö÷»úÃû³Æ, È»ºóÔÙ mount -a -t nfs À´¼Ó¹ÒÈË¼Ò export ³öÀ´µÄ fs.

------[·¶ÀýÈçÏÂ]------------------------------------------------
if [ -x /etc/init.d/network ]
then
/etc/init.d/network
fi
# È»ºóÉ趨 hostname
# If there's no /etc/HOSTNAME, fall back on this default:
if [ ! -r /etc/HOSTNAME ]; then
echo "Henry.Dorm10.NCTU.edu.tw" > /etc/HOSTNAME
fi
cat /etc/HOSTNAME | cut -f1 -d . > /etc/hostname
hostname --file /etc/hostname

# Now that TCP/IP is configured, mount the NFS file systems in /etc/fstab.
echo "Mounting remote file systems..."
mount -a -t nfs
------[·¶Àý½áÊø]------------------------------------------------

ºÃ, Õâʱ²Å°ÑËùÓÐµÄ file system(º¬ nfs) ¶¼ mount ÆðÀ´ÁË,
ËùÒÔÏÖÔÚÁ¢¿ÌÒª×öµÄÊÂ, ¾ÍÊǸüР/etc/ld.so.cache Õâ¸öµµ,
É趨 system clock, È»ºóÇå³ý /tmp, /var/run ¼° /var/lock
ϵĴ󲿷ÝÀ¬»ø:

* /sbin/ldconfig
* clock -s
* Çå³ý /tmp, /var/run, /var/lock ϵÄÀ¬»ø

OK, /tmp, /var/run ¼° /var/lock ÕâЩĿ¼ÏµÄÀ¬»ø¶¼Çå¿ÕÁË,
Õâʱ²ÅÈ¥Ö´ÐÐ /etc/rc.boot/ ϵÄËùÓÐ script (ÆäÖÐ run-parts
ÊÇÒ»¸ö¹¤¾ß³Ìʽ, Ëü»á°ÑÄã¸øµÄ²ÎÊý[Ŀ¼]ÏÂËùÓÐµÄ scripts ¶¼
¸øËüÅܸöÒ»´Î):

* run-parts /etc/rc.boot

Èç¹ûûÓÐ run-parts Õâ¸ö¹¤¾ß, ²»·Á×Ô¼ºÑ§×ÅÓà shell script
дһ¸ö; »òÊÇÓñ¿·½·¨: »¹ÊǹԹԵØдÔÚÕâ¸ö /etc/init.d/boot
script ÄÚ°É......

È»ºóÐÞ¸Ä /dev/ttyXX µÄÊôÐÔ (¹ØÓÚ pty256 ÈݺóÔÙ½éÉÜ):

* chmod 666 /dev/tty[pqrstuvwxyzabcde]*
* chown root.tty /dev/tty[pqrstuvwxyzabcde]*

ÔÙÀ´¾Í¿´Ä㻹ÓÐʲôÊ´òËãÔÚÕâ¶ù¾ÍÏÈ´¦ÀíµôµÄ, Ò²Ò»²¢ÔÚ´ËдÈë,
»òÊÇд¸ö script ¶ªµ½ /etc/rc.boot/ ÏÂÒ²ÊÇÒ»ÑùµÄ¡£ ÀýÈç°Ñ
powerd ÅÜÆðÀ´¡¢½¨Á¢ /etc/motd¡¢½¨Á¢ /etc/issue.net¡¢½¨Á¢Ò»
Щ links......¶¼ÊDz»´íµÄÖ÷Òâ¡£

ÒÔÏÂÊÇÎÒµÄ /etc/init.d/boot Õâ¸ö script:

[¸½¼þÒ»]
 

PATH="/sbin:/bin:/usr/sbin:/usr/bin"
umask 022

echo
echo "Running /etc/init.d/boot..."
echo

# enable kerneld
if [ -x /sbin/kerneld ]; then
/sbin/kerneld
fi

# °Ñ md ÅÜÆðÀ´
if [ -s /etc/mdtab -a -f /sbin/mdadd ]
then
mdadd -ar
fi

echo "Activating swap..."
swapon -a 2>/dev/null

# Ensure that bdflush (update) is running before any major I/O is
# performed (the following is a good example of such activity :).
update &

# Check the integrity of all file systems (if not a fastboot).
if [ ! -f /fastboot ]
then
# Ensure that root is quiescent and read-only before fsck'ing.
mount -n -o remount,ro /
if [ $? = 0 ]
then
echo "Checking file systems..."
fsck -A -a
# If there was a failure, drop into single-user mode.
#
# NOTE: "failure" is defined as exiting with a return code of
# 2 or larger. A return code of 1 indicates that file system
# errors were corrected but that the boot may proceed.
if [ $? -gt 1 ]
then
# Surprise! Re-directing from a HERE document (as in
# "cat << EOF") won't work, because the root is read-only.
echo
echo "fsck failed. Please repair manually and reboot. Please note"
echo "that the root file system is currently mounted read-only. To"
echo "remount it read-write:"
echo
echo " bash# mount -n -o remount,rw /"
echo
echo "CONTROL-D will reboot the system."
echo
# Start a single user shell on the console
/sbin/sulogin /dev/console
sync
reboot
fi
echo
else
echo "*** ERROR! Cannot fsck because root is not read-only!"
echo
fi
else
echo "*** Fast boot ... skipping disk checks"
echo
fi

# Remount the root file system in read-write mode.
mount -n -o remount,rw /

# Load the appropriate modules.
if [ -x /etc/init.d/modules ]
then
/etc/init.d/modules
fi

# Remove /etc/mtab*, /etc/rmtab, /etc/nologin and /fastboot.
rm -f /etc/mtab* /etc/nologin /fastboot /etc/rmtab

# update /etc/psdatabase
psupdate 2> /dev/null
# or
#ps -U 2> /dev/null

# Mount local file systems in /etc/fstab.
echo "Mounting local file systems..."
mount -avt nonfs

# Execute swapon command again, in case we want to swap to
# a file on a now mounted filesystem.
swapon -a 2>/dev/null

# Setup the network interfaces. Note that /var/run and /var/lock
# are cleaned up after this, so don't put anything in the "network"
# script that leave a pidfile or a lockfile.
if [ -x /etc/init.d/network ]
then
/etc/init.d/network
fi

# Set hostname.
# If there's no /etc/HOSTNAME, fall back on this default:
if [ ! -r /etc/HOSTNAME ]; then
echo "Henry.Dorm10.NCTU.edu.tw" > /etc/HOSTNAME
fi
cat /etc/HOSTNAME | cut -f1 -d . > /etc/hostname
hostname --file /etc/hostname

# Now that TCP/IP is configured, mount the NFS file systems in /etc/fstab.
echo "Mounting remote file systems..."
mount -a -t nfs

# Update all the shared library links automatically
echo "Update /etc/ld.so.cache and all the shared library links."
/sbin/ldconfig

# Set GMT="-u" if your system clock is set to GMT, and GMT=""
# if not.
GMT=""
# Set and adjust the CMOS clock.
clock -s $GMT
if [ ! -f /etc/adjtime ]
then
echo "0.0 0 0.0" > /etc/adjtime
fi
clock -a $GMT

# Now that /usr/lib/zoneinfo should be available, announce the local time.
echo
echo "Local time: `date`"
echo

# Wipe /tmp (and don't erase `lost+found', `quota.user' or `quota.group')!
# Note that files _in_ lost+found _are_ deleted.
echo -n "Cleaning up /tmp, /var/run and /var/lock... "
( cd /tmp && \
find . \
! -name .\
! \( -name lost+found -uid 0 \) \
! \( -name quota.user -uid 0 \) \
! \( -name quota.group -uid 0 \) \
-depth -exec rm -rf -- {} \; )
# Clean up any stale locks.
( cd /var/lock && find . -type f -exec rm -f -- {} \; )
# Clean up /var/run and create /var/run/utmp so that we can login.
( cd /var/run && find . ! -type d -exec rm -f -- {} \; )
: > /var/run/utmp
echo "done."

# Run the package-specific boot scripts in /etc/rc.boot.
run-parts /etc/rc.boot
# Set pseudo-terminal access permissions.
chmod 666 /dev/tty[pqrstuvwxyzabcde]*
chown root.tty /dev/tty[pqrstuvwxyzabcde]*

# Setup the /etc/issue.net to reflect the current kernel level:
cat /etc/issue > /etc/issue.net
uname -a >> /etc/issue.net
echo >> /etc/issue.net

touch /etc/motd

# and startup powerd
echo "Start up the genpowerd" ; /sbin/genpowerd /dev/UPS henry

--------------------- --------------------- ---------------------
ÕâÏÂÎÒÃÇµÄ /etc/init.d/boot ÅÜÍêÁË, ÒÀÕÕ /etc/inittab
µÄÉ趨, ÊÇÅÜ runlevel=3, Ö´ÐÐ /etc/init.d/rc 3 Õâ¸öÖ¸Áî¡£

/etc/init.d/rc ÊÇÒ»¸ö²»´í (´ÏÃ÷£¿) µÄ shell script,
ÎÒÃÇÀ´½éÉÜÒ»ÏÂËüµÄÔË×÷·½Ê½¡£

ÔÚ SysV init 2.6 ËùÓÃµÄ /etc/ ÏÂ, ³ýÁË init.d/ ¼°
boot/ ÕâÁ½¸ö×ÓĿ¼Íâ, ÉÐÓÐ:

drwxr-xr-x 2 root 1024 May 28 09:08 rc0.d/
drwxr-xr-x 2 root 1024 May 28 09:08 rc1.d/
drwxr-xr-x 2 root 1024 May 29 09:54 rc2.d/
drwxr-xr-x 2 root 1024 May 28 09:08 rc3.d/
drwxr-xr-x 2 root 1024 May 28 09:08 rc4.d/
drwxr-xr-x 2 root 1024 May 28 09:08 rc5.d/
drwxr-xr-x 2 root 1024 May 28 09:08 rc6.d/

ÕâÆ߸ö×ÓĿ¼, ÎÒÃÇÒÔ rc3.d À´×÷ʾ·¶:

# dir rc3.d/
S20cron -> ../init.d/cron*
S20gpm -> ../init.d/gpm*
S20httpd -> ../init.d/httpd*
S20innbbsd -> ../init.d/innbbsd*
S20ip_acct -> ../init.d/ip_acct*
S20lpd -> ../init.d/lpd*
S20netbase -> ../init.d/netbase*
S20netstd_misc -> ../init.d/netstd_misc*
S20nfs -> ../init.d/nfs*
S20quota -> ../init.d/quota*
S30sendmail -> ../init.d/sendmail*
S30syslogd -> ../init.d/syslogd*

ÕâЩ¶¼ÊÇÒ»¸öÒ»¸öµÄ symbolic link µ½ /etc/init.d/ Ï嵀 script,
ÆäÖÐ S20 ÊÇÒ»ÖÖ¿ØÖÆ˵Ã÷, S ÊDZíʾ start (K ÊDZíʾ kill), 20
Õâ¸öÊý×Ö±íʾËüÃǵÄÖ´ÐÐ˳Ðò (20 ±È 30 ÏÈÖ´ÐÐ, ͬÊý×ÖÔòÕÕ×Öĸ
˳Ðò¼´¿É)¡£

/etc/init.d/rc ¾ÍÊÇÕÕ¸ø¶¨µÄ runlevel Êý×Ö, È¥¶ÔÓ¦µÄĿ¼¿´ÕâЩ
¶«Î÷À´¾ö¶¨ÒªÅÜÄÇЩ script.

ÄÇô, init.d/ ϵÄÄÇЩ script ÓÖÊÇÔõô»ØÊÂÄØ£¿
ÎÒÃÇÀ´¿´Ò»ÏºÃÁË:

root@Henry:/etc# dir init.d/
total 45
-rwxr-xr-x 1 root 5231 May 28 17:47 boot*
-rwxr-xr-x 1 root 290 May 28 09:08 cron*
-rwxr-xr-- 1 root 2250 May 29 01:29 genpowerfail*
-rwxr-xr-x 1 root 283 May 28 06:41 gpm*
-rwxr-xr-x 1 root 707 Feb 29 20:17 halt*
-rwxr-xr-x 1 root 718 May 28 06:27 httpd*
-rwxr-xr-x 1 root 494 May 28 07:05 innbbsd*
-rwxr-x--- 1 root 333 May 28 07:12 ip_acct*
-rwxr-xr-x 1 root 343 May 28 06:35 lpd*
-rwxr-xr-x 1 root 500 May 28 05:25 modules*
-rwxr-xr-x 1 root 699 May 28 06:12 netbase*
-rwxr-xr-x 1 root 391 Mar 19 10:32 netstd_init*
-rwxr-xr-x 1 root 598 May 29 09:54 netstd_misc*
-rwxr-xr-x 1 root 1372 May 29 10:05 network*
-rwxr-xr-x 1 root 1208 May 28 05:36 nfs*
-rwxr-xr-x 1 root 1258 Dec 28 08:02 powerfail*
-rwxr-x--- 1 root 891 May 28 06:45 quota*
-rwxr-xr-x 1 root 2928 Jan 4 19:59 rc*
-rwxr-xr-x 1 root 653 Feb 29 20:17 reboot*
-rwxr-xr-x 1 root 696 May 28 07:34 sendmail*
-rwxr-xr-x 1 root 527 Mar 20 00:44 single*
-rwxr-xr-x 1 root 1078 Dec 28 08:21 skeleton*
-rwxr-xr-x 1 root 640 May 29 08:21 syslogd*

ºÇºÇ, ûÏëµ½ÓÐÕâô¶à°É£¿Ò»¸öÌṩ±È½Ï¶à·þÎñµÄ¹¤×÷Õ¾, ´ó¸Å
¾ÍÐèÒªÕâЩ¡£ ³ýÁË boot, rc, network, modules ÊÇÎÒÃǽéÉÜ
¹ýµÄÖ®Íâ, ÆäËû¶¼ÊǸø /etc/rc[0-6].d/ ×ö symbolic link ÓÃ
È¥ÁË¡£

OK, ÎÒ½ÐÒ»¸ö script ³öÀ´¸ø´ó¼Ò¿´:

-------[/etc/init.d/netbase]----------------------------
#!/bin/sh
#
# Start networking daemons.

test -f /usr/sbin/rpc.portmap || exit 0

case "$1" in
start)
echo -n "Starting base networking daemons: "
echo -n "rpc.portmap "
start-stop-daemon --start --quiet --exec /usr/sbin/rpc.portmap
echo -n "xinetd "
start-stop-daemon --start --quiet --exec /usr/sbin/xinetd
echo
;;
stop)
start-stop-daemon --stop --quiet --oknodo --exec /usr/sbin/xinetd
start-stop-daemon --stop --quiet --oknodo --exec /usr/sbin/rpc.portmap
killall -9 slattach 2>/dev/null || exit 0
;;
reload)
start-stop-daemon --stop --oknodo --signal 10 --exec /usr/sbin/xinetd
;;
*)
echo "Usage: /etc/init.d/netbase {start|stop|reload}"
exit 1
;;
esac

exit 0

-------[end]-----------------------------------------------------------------

ÆäÖÐ start-stop-daemon ÊÇÒ»¸ö perl script, ²ÎÊý --start ÊÇÅÜËüÈ¥Æô¶¯
ÄǸö daemon (ÀýÈç xinetd), ²ÎÊý --stop ÊǽÐËüɱµôÄǸö daemon¡£ Ò»°ã
¶øÑÔ, Èç¹û¸øµÄ signal ¶ÔµÄ»° (Ô¤ÉèÖµÊÇ 9, SIGKILL), ÉпÉʹ¸Ã daemon
reload Ò»´ÎËüµÄÅäÖÃÎļþ (ÒÔ xinetd ΪÀýÊÇ 10, SIGUSR1), ¶øͨ³£¶¼ÊǸø
1, SIGHUP¡£

S20netbase Õâ¸ö symbolic link »áʹµÃ /etc/init.d/rc È¥Æô¶¯Ëü, Ò²¾ÍÊÇ
ÅÜ '/etc/init.d/netbase start', ʹµÃ rpc.portmap ¼° xinetd Ö´ÐÐÆðÀ´,
¾Í´ïµ½ÎÒÃÇËùÒªÇóµÄ¡£

ÆäËûÈç lpd¡¢gpm¡¢httpd¡¢nfs¡¢Ò²ÊÇÈç´Ë¡£ ²¹³äÒ»µãµÄÊÇ, nfs ÀàµÄ daemon
Ò»¶¨µÃÔÚ rpc.portmap ÅÜÆðÀ´Ö®ºó²ÅÄÜÕýÈ·¶¯×÷ (ÒòΪ nfs Ò²ÊÇÒ»ÖÖ rpc),
µ«ÔÚ´Ë S20netbase »á±È S20nfs ÏÈÅÜ (¿¼ÂÇ×Öĸ˳Ðò), ËùÒÔ¿´ÆðÀ´Ã»ÓÐʲô
ÎÊÌâ¡£ ×¢ÒâÒ»ÏÂÖ´ÐÐ˳ÐòÊǺÜÖØÒªµÄÊ¡£

ÔÚ´ËÔÙ²¹³äÒ»µã, debian ÓÐÒ»¸ö¹¤¾ß³ÌÐò update-rc.d ºÜÓÐÓÃ:

-----------[man update-rc.d]-------------------------------------
NAME
update-rc.d - install and remove System-V style init
script links

SYNOPSIS
update-rc.d remove

update-rc.d defaults [ | denumber> ]

update-rc.d start | stop level> [ [ [...]]] .

----------[end of part]------------------------------------------

Ëü»á°ïÖúÄã°ÑÐÂÔìºÃµÄ script ¼ÓÈë /etc/rc[0-6].d/ ÖÐµÄ symbolic
link. Èç¹ûÊÇ defaults, ÔòÔÚ rc[2-5].d/ ÏÂÔì S20xxxxx, rc[016].d/
ÏÂÔì K20xxxxx µÄ symbolic link, ²»´í°É£¿

ºÃ, /etc/init.d/rc 3 Ò²ÅÜÍêÁË, ÔÙÀ´¾ÍÊÇ¿ª console
ÁË¡£ ÒÀÕÕ inittab µÄÉ趨, ÊÇÔÚ tty1 ~ tty6 ¿ªÁù¸ö
virtual console, ËùÒÔÎÒÃÇ¿ÉÒÔÓÃ atl-f1 µ½ f6 À´ÇÐ
»» virtual console µÄ²Ù×÷¡£ login Ö®ºó, ÎÒÃǻῴ
µ½ÏÂÃæµÄ process:

root@Henry:/etc# ps ax |grep getty
165 v02 S 0:00 /sbin/agetty 19200 tty2
166 v03 S 0:00 /sbin/agetty 19200 tty3
167 v04 S 0:00 /sbin/agetty 19200 tty4
168 v05 S 0:00 /sbin/agetty 19200 tty5
169 v06 S 0:00 /sbin/agetty 19200 tty6

ÒòΪÎÒÃÇÒѾ­ login ÁË, Óõô tty1 ÁË, ËùÒÔ¿´²»µ½ tty1
ÔÚÅÜ agetty.

ÓÐ¹Ø SysV init 2.6 °æ¾ÍÏȽ²µ½ÕâÀï, ´ó¼ÒÓÐûÓÐʲôÎÊÌ⣿

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