1. 重要的目录说明
| 目录 |
目录说明 |
| /bin |
常用的二进制命令目录。比如ls、cp、mkdir、cut等 |
| /boot |
存放用于系统引导时使用的各种文件 |
| /dev |
用于存放设备文件 |
| /etc |
存放系统配置文件 |
| /home |
普通用户的家目录默认数据存放目录 |
| /lib |
存放跟文件系统中的程序运行所需要的共享库及内核模块 |
| /lost+found |
存放磁盘文件或系统破的临时文件位置 |
| /mnt |
系统管理员安装临时文件系统的挂载点 |
| /opt |
自定义安装软件包的目录 |
| /proc |
虚拟目录，进程信息及内核信息 |
| /root |
Linux超级权限用户root的家目录 |
| /sbin |
超级管理员运行命令存放的目录 |
| /selinux |
SELinux存放配置文件的位置 |
| /srv |
服务启动之后需要访问的数据目录 |
| /tmp |
一般用户或正在执行的程序临时存放文件的目录 |
| /usr |
系统存放应用程序的目录 |
| /var |
放置系统执行过程中经常变化的文件 |
在Linux系统中一切皆文件
2.linux中重要的子目录
2.1 网卡目录
/etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0 ##网卡名称
HWADDR=00:0c:29:b9:47:51 #物理名称，网卡的mac地址
TYPE=Ethernet ##以太网
UUID=d560c64b-cdd4-419f-9c80-1a80e643252b ##磁盘的唯一标识
ONBOOT=yes ###网卡是否开机自启动
NM_CONTROLLED=yes #是否接受软件控制
BOOTPROTO=none ##网卡启动的时候如何获取IP地址（获取协议）static：静态分配IP地址；DHCP：动态分配IP地址（自动获取IP地址）
DNS1=10.0.0.2
USERCTL=no
PEERDNS=yes
IPV6INIT=no
IPADDR=10.0.0.200 ##IP地址
NETMASK=255.255.255.0 ##子网掩码
GATEWAY=10.0.0.254 @###网关地址
DNS2=10.0.0.2 ###dns地址 网址域名 在网络中使用的
###关闭某一网卡
ifdown eth0 && ifup eth0
###重启所有网卡
/etc/init.d/network restart
2.2把主机名（域名）解析为ip地址
cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
2.3主机名
/etc/sysconfig/network
2.4开机启动时-磁盘分区和目录的挂载关系
cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Sun Jul 16 13:01:56 2017
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=ce5a5255-0aa2-434b-9af3-0991af9c03d1 / ext4 defaults 1 1
UUID=a098c44e-84f9-4d42-b2e7-8074335f77e5 /boot ext4 defaults 1 2
UUID=5e33d67b-dc90-44da-9b81-ba15cc31dd46 swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
第一列====磁盘分区 设备
第二列====目录（挂载点）
2.5开机启动的脚本文件（文件中放着开机需要启动的命令）开机自动运行的命令或脚本
cat /etc/rc.local
#!/bin/sh
#
# This script will be executed *after* all the other init scripts.
# You can put your own initialization stuff in here if you don't
# want to do the full Sys V style init stuff.
2.6放着Linux系统的运行级别----不同的状态
at /etc/inittab
# inittab is only used by upstart for the default runlevel.
#
# ADDING OTHER CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.
#
# System initialization is started by /etc/init/rcS.conf
#
# Individual runlevels are started by /etc/init/rc.conf
#
# Ctrl-Alt-Delete is handled by /etc/init/control-alt-delete.conf
#
# Terminal gettys are handled by /etc/init/tty.conf and /etc/init/serial.conf,
# with configuration in /etc/sysconfig/init.
#
# For information on how to write upstart event handlers, or how
# upstart works, see init(5), init(8), and initctl(8).
#
# Default runlevel. The runlevels used are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:3:initdefault:
2.7运行级别说明
| 运行级别 |
说明 |
| 0 |
关机 |
| 1 |
单用户模式，root密码忘了，默认没有网络 |
| 2 |
多用户模式，没有NFS（网路文件系统 |
| 3 |
完全多用户模式，命令模式 |
| 4 |
没有使用 |
| 5 |
图像界面模式，桌面模式 |
| 6 |
重启 |
2.71如何切换运行级别
[root@zzz]# init 5
[root@zzz]# runlevel ##查看当前运行级别
3 5 ##上一次运行级别 当前运行级别
[root@zzz]#
永久切换
[root@zzz39 zzz]# grep "id:" /etc/inittab
id:3:initdefault:
2.8 存放的是软件管理的命令
cd /etc/init.d/
abrt-ccpp functions lvm2-monitor postfix saslauthd
abrtd haldaemon mdmonitor psacct single
abrt-oops halt messagebus quota_nld smartd
acpid ip6tables netconsole rdisc sshd
atd iptables netfs rdma svnserve
auditd irqbalance network restorecond sysstat
blk-availability kdump nfs-rdma rngd udev-post
cpuspeed killall ntpd rsyslog
crond lvm2-lvmetad ntpdate sandbox
2.9 存放系统别名----存放系统环境变量
[root@zzz39 ~]# cat /etc/profile
# /etc/profile
# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc
# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.
................
2.10用户的环境变量
cat ~/.bashrc
# .bashrc
# User specific aliases and functions
#alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi
...........................
2.11用户的环境变量
cat ~/.bash_profile
# .bash_profile
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi
# User specific environment and startup programs
PATH=$PATH:$HOME/bin
export PATH
2.12用户登录或远程连接之后显示的内容
[root@zzz ~]# cat /etc/motd
[root@zzz ~]# echo "welcome to linux training" >> /etc/motd
Last login: Wed Jul 19 20:09:36 2017 from 10.0.0.1
welcome to linux training
2.13/usr/local/编译安装的默认位置
安装软件的方法
- yum 软件管家（yellow dog）
从网上下载 自动替你安装
- rpm 命令安装软件
缺少东西自己加工，自己下载
- 编译安装
自己做，自己编译
./configure make make install
2.14 /var/log/secure用户的登录信息
cat /var/log/secure
Jul 16 13:15:05 zzz39 sshd[1454]: Server listening on 0.0.0.0 port 22.
Jul 16 13:15:05 zzz39 sshd[1454]: Server listening on :: port 22.
Jul 16 13:16:45 zzz39 login: pam_unix(login:session): session opened for user root by LOGIN(uid=0)
Jul 16 13:16:45 zzz39 login: ROOT LOGIN ON tty1
Jul 16 13:28:38 zzz39 sshd[2096]: reverse mapping checking getaddrinfo for bogon [10.0.0.1] failed - POSSIBLE BREAK-IN ATTEMPT!
Jul 16 13:28:45 zzz39 sshd[2096]: Accepted password for root from 10.0.0.1 port 58100 ssh2
Jul 16 13:28:45 zzz39 sshd[2096]: pam_unix(sshd:session): session opened for user root by (uid=0)
Jul 16 17:10:41 zzz39 sshd[1605]: Server listening on 0.0.0.0 port 22.
Jul 16 17:10:41 zzz39 sshd[1605]: Server listening on :: port 22.
2.15用户的系统日志
/var/log/messages
tail -20 /var/log/messages
Jul 19 21:44:10 zzz39 init: prefdm main process (6959) terminated with status 1
Jul 19 21:44:10 zzz39 init: prefdm main process ended, respawning
Jul 19 21:44:10 zzz39 init: prefdm main process (6976) terminated with status 1
Jul 19 21:44:10 zzz39 init: prefdm main process ended, respawning
Jul 19 21:44:11 zzz39 init: prefdm main process (6993) terminated with status 1
Jul 19 21:44:11 zzz39 init: prefdm main process ended, respawning
Jul 19 21:44:11 zzz39 init: prefdm main process (7010) terminated with status 1
Jul 19 21:44:11 zzz39 init: prefdm main process ended, respawning
Jul 19 21:44:11 zzz39 init: prefdm main process (7027) terminated with status 1
Jul 19 21:44:11 zzz39 init: prefdm main process ended, respawning
Jul 19 21:44:11 zzz39 init: prefdm main process (7044) terminated with status 1
2.16cpu信息
cpu cores : 2
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 22
wp : yes
...................
2.17内存的信息
cat /proc/meminfo
MemTotal: 1004112 kB
MemFree: 656036 kB
Buffers: 44760 kB
Cached: 179504 kB
SwapCached: 0 kB
Active: 101796 kB
Inactive: 136168 kB
Active(anon): 13920 kB
Inactive(anon): 8 kB
Active(file): 87876 kB
Inactive(file): 136160 kB
.........................
2.18平均负载 ，系统的繁忙程度
cat /proc/loadavg
0.00 0.01 0.00 2/181 7211
2.19系统挂载信息
cat /proc/mounts
rootfs / rootfs rw 0 0
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
devtmpfs /dev devtmpfs rw,relatime,size=487428k,nr_inodes=121857,mode=755 0 0
devpts /dev/pts devpts rw,relatime,gid=5,mode=620,ptmxmode=000 0 0
*tmpfs /dev/shm tmpfs rw,relatime 0 0
/dev/sda3 / ext4 rw,relatime,barrier=1,data=ordered 0 0
/proc/bus/usb /proc/bus/usb usbfs rw,relatime 0 0
/dev/sda1 /boot ext4 rw,relatime,barrier=1,data=ordered 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw,relatime 0 0
/dev/sr0 /mnt/cdrom iso9660 ro,relatime 0 0