[Turn] talking about the startup process of Linux system

Original: http://blog.csdn.net/justdb/article/details/9621271 copyright notice: This article for Bo Master original article.

Linux system start-up by reading different configuration files, execute the corresponding shell script to complete. Of course this article is simply from the perspective of the file analysis, a deeper level of this article is not covered.

The following files were read mainly:

1/boot/grub/grub.conf2/etc/Inittab3/ETC/RC5.D (RC.D)0- AboutSeq4/etc/passwd (login,input username and password)5/etc/Shadow6/etc/profile:init the ENVvarof user7/etc/profile.d/*. SH8 ~/.bash_profile9 ~/.bash_historyTen ~/.BASHRC One /ETC/BASHRC

Let's start by looking at the grub.conf file

1 [email protected] grub]# ll menu.lst2lrwxrwxrwx.1Root root One7o?=o?= + Ten: theMenu.lst./grub.conf3 [email protected] grub]# pwd4/boot/Grub5 grub.conf file Contents:6 default=0  7timeout=5  8Splashimage= (hd0,0)/boot/grub/splash.xpm.gz9 HiddenmenuTenTitle Red Hat Enterprise Linux (2.6. +- -. el6.i686) OneRoot (hd0,0)   Akernel/boot/vmlinuz-2.6. +- -. el6.i686 ro -root=uuid=ed98469d-857b-4ae5-91e4-118e0167ead7 Rd_no_luks RD_NO_LVM -Lang=en_us. utf-8RD_NO_MD Quiet Sysfont=lat arcyrheb-Sun16 RHGB theCrashkernel=auto keyboardtype=pc keytable=US RD_NO_DM -initrd/boot/initramfs-2.6. +- -. el6.i686.img

Execute the runlevel command to see that the boot level is 5

1 [email protected] grub]# runlevel   2 5

We enter the ETC directory, we can see a lot of RCX.D directory

1 [[email protected] grub]# cd/etc/init.d  2   3 [[email protected] init.d]# CD/etc  4[[email protected] etc]# CD RC  5 rc          rc0.d/      rc1.d/      rc2.d/      rc3.d/      rc4.d/      rc5.d/  6 rc6.d/      rc.d/       rc.local    Rc.sysinit    

We go into the/ETC/PROFILE.D directory and we can see a lot of executable scripts

1[Email protected] test]# LL/ETC/PROFILE.D/*. SH2 -rw-r--r--. 1 root root 1143 Apr 2010/etc/profile.d/colorls.sh3 -rw-r--r--. 1 root root (APR) 2010/etc/profile.d/cvs.sh4 -rw-r--r--. 1 root root 192 Dec 2005/etc/profile.d/glib2.sh5 -rw-r--r--. 1 root root 2010/etc/profile.d/gnome-ssh-askpass.sh6 -rwxr-xr-x. 1 root root 288 Sep 2009/etc/profile.d/kde.sh7 -rw-r--r--. 1 root root 2706 Sep 2 2010/etc/profile.d/lang.sh8 -rw-r--r--. 1 root root 108 Feb 7 2007/etc/profile.d/less.sh9 -rw-r--r--. 1 root root 933 June 2010/etc/profile.d/qt.shTen -rw-r--r--. 1 root root 2142 Sep 8 2010/etc/profile.d/udisks-bash-completion.sh One -rw-r--r--. 1 root root 269 may 2010/etc/profile.d/vim.sh A -rw-r--r--. 1 root root 169 may 2009/etc/profile.d/which2.sh

Because the boot level is 5, so we go into rc5.d, we can see a lot of files, s means when the system starts to execute, K means when the system shuts down to execute.

[Email protected] grub]# ll/etc/rc5.d/k01certmonger k50netconsole k75ntpdate k89rdisc s11auditd S24avahi-Daemon s26pcscd s82abrtd k01smartd k50snmpd k76ipsec k95cgconfig S11portreserve S24nfslock S26udev-post S85qpidd k02oddjobd k50snmptrapd k80kdump k95firstboot s12rsyslog S24openct s28autofs s90crond k10psacct k50vsftpd k80sblim-SFCB s00microcode_ctl s13cpuspeed s24rpcgssd s30vboxadd s95atd K10SASLAUTHD K60nfs K80SSSD s01sysstat s13irqbalance s24rpcidmapd s30vboxadd-x11 s97rhnsd k15httpd k69rpcsvcgssd k84wpa_supplicant s02lvm2-monitor s13rpcbind s25cups S35vboxadd-service s98tog-Pegasus K20tomcat6 k73ypbind k86cgred s08ip6tables s15mdmonitor s25netfs S50bluetooth s99local k36mysqld k74nscd k87restorecond s08iptables S 22messagebus s26acpid s55sshd k50dnsmasq k74ntpd k88nslcd S 10network S23networkmanager S26haldaemon S80postfix

Let's take a look at the contents of the. bashrc file in the user's home directory

1[email protected] grub]# cat ~/. BASHRC2 #. BASHRC3   4 # User specific aliases and functions5   6Alias rm='rm-i'  7Alias cp='cp-i'  8Alias mv='mv-i'  9   Ten# SourceGlobalDefinitions One if[-f/etc/BASHRC]; Then A. /etc/BASHRC -Fi

Let's take a look at the contents of the. bash_profile file in the user's home directory

1[email protected] grub]# cat ~/. Bash_profile2 #. Bash_profile3   4 # Get The aliases and functions5 if[-F ~/. BASHRC]; Then6. ~/. BASHRC7 fi8   9 # User specific environment and startup programsTen    OnePath= $PATH: $HOME/bin A    -Export PATH

A complete flowchart such as:

[Turn] talking about the startup process of Linux system