Rhel 7.3 基本操作：
1.1 Linux 终端使用，Shell 提示符 Bash shell基本语法
1.2 基本命令的使用：ls pwd cd
1.3 查看当前系统时间和BIOS硬件时间
1.4 Linux 如何获得帮助，Linux开关机命令：shutown init
1.5 Linux 7个启动级别，设置服务器在来电后自动开机
Keywords[关键词]
Terminal：终端
netwok-scripts ：网络脚本
passwd：密码文件
nologin：禁止登陆
shutdown：关机
reboot：重启
poweroff：关机
grep：过滤
localhost：本机
useradd：添加用户
graphical：图形
tty: 控制终端
tty1-tty6：
tty1：图形界面
tty2-6：字符界面
图形界面切换到字符界面终端：Ctrl+Alt+F2-6
字符界面切换到另外一个字符界面终端:Alt+F2-6
字符界面切换到图形界面:Alt+F1
pts:虚拟终端
新建虚拟终端：Ctrl+Shift+T
终端切换：Alt+数字键
关闭终端：Alt+F4
放大字体：Ctrl+Shift+T +
缩小字体：Ctrl+-
使用whoami查看当前登录的用户：
[root@marklin ~]# whoami
root
使用who am i 查询当前终端对应的
[root@marklin ~]# who am i
root pts/0 2017-08-27 05:13 (:0)
[root@marklin ~]#
使用w查看pts的进程：
[root@marklin ~]# w
05:39:30 up 29 min, 2 users, load average: 0.04, 0.04, 0.08
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root :0 :0 05:11 ?xdm? 2:07 0.55s gdm-session-wor
root pts/0 :0 05:13 2.00s 0.13s 0.06s w
[root@marklin ~]#
ssh 远程连接Linux服务器:ssh 用户名@IP地址
[root@marklin ~]# ssh root@192.168.3.5
The authenticity of host '192.168.3.5 (192.168.3.5)' can't be established.
ECDSA key fingerprint is aa:24:b8:f8:5d:3c:6c:1c:70:ee:0b:da:37:73:9e:2b.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.3.5' (ECDSA) to the list of known hosts.
root@192.168.3.5's password:
Last login: Sun Aug 27 05:11:58 2017
[root@marklin ~]#
使用grep过滤pts：ps -aux | grep pts
[root@marklin ~]# ps -aux | grep pts
root 2743 0.0 0.1 116560 3256 pts/0 Ss 05:13 0:00 bash
root 3198 0.0 0.3 80720 6828 pts/0 S+ 05:41 0:00 ssh root@192.168.3.5
root 3199 0.2 0.2 145056 5204 ? Ss 05:41 0:00 sshd: root@pt/1
root 3204 0.0 0.1 116440 3180 pts/1 Ss 05:42 0:00 -bash
root 3269 0.0 0.0 153140 1872 pts/1 R+ 05:44 0:00 ps -aux
root 3270 0.0 0.0 112648 960 pts/1 S+ 05:44 0:00 grep --color=auto pts
[root@marklin ~]# ^C
[root@marklin ~]#
pts：pseudo-terminal slave 伪终端：通过ssh 相关连接工具连接上后，显示打印pts
Shell 提示符：
[用户@主机 当前目录名称]提示符：[root@marklin ~]#
其中root为#，而普通用户为：$
Bash Shell 基本语法：
Linux 命令：
输入命令：
命令 空格 [选项]([参数]) 空格 [选项的值] ([参数的值])，空格为分隔符
常见选项(参数)：-字母 或--加单词
-h --help;
基本命令操作：
ls命令：
作用：查看当前目录下有哪些文件
语法：ls 目录 ,如果不加目录查看当前目录
参数：
-I ：显示详细信息 系统里面的快捷方式：#II-ls -I
-a：显示隐藏文件
-d：查看目录，不查看里面的内容
-h:方便阅读文件大小
使用ls 查看当前目录：
[root@marklin ~]# ls
anaconda-ks.cfg Documents initial-setup-ks.cfg Pictures Templates
Desktop Downloads Music Public Videos
[root@marklin ~]#
[root@marklin ~]# ls -h
anaconda-ks.cfg Documents initial-setup-ks.cfg Pictures Templates
Desktop Downloads Music Public Videos
[root@marklin ~]#
使用ls -lh 查看当前目录详情：
[root@marklin ~]# ls -lh
total 8.0K
-rw-------. 1 root root 1.9K Aug 27 05:03 anaconda-ks.cfg
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Desktop
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Documents
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Downloads
-rw-r--r--. 1 root root 2.0K Aug 27 05:11 initial-setup-ks.cfg
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Music
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Pictures
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Public
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Templates
drwxr-xr-x. 2 root root 6 Aug 27 05:11 Videos
[root@marklin ~]#
讲解：
权限 连接数 用户名 文件大小 文件创建日期 具体文件名
-rw-------. 1 root root 1.9K Aug 27 05:03 anaconda-ks.cfg
使用ls -a 显示隐藏文件:
[root@marklin ~]# ls -a
. .bashrc Documents initial-setup-ks.cfg .ssh
.. .cache Downloads .local .tcshrc
anaconda-ks.cfg .config .esd_auth .mozilla Templates
.bash_history .cshrc .gnome2 Music Videos
.bash_logout .dbus .gnome2_private Pictures
.bash_profile Desktop .ICEauthority Public
[root@marklin ~]#
使用cd +目录 切换目录：
[root@marklin ~]# ls
anaconda-ks.cfg Documents initial-setup-ks.cfg Pictures Templates
Desktop Downloads Music Public Videos
[root@marklin ~]# cd Desktop
[root@marklin Desktop]#
[root@marklin ~]# ls -l /etc
total 1452
drwxr-xr-x. 3 root root 101 Aug 27 04:51 abrt
-rw-r--r--. 1 root root 16 Aug 27 05:02 adjtime
drwxr-xr-x. 2 root root 116 Aug 27 04:55 akonadi
-rw-r--r--. 1 root root 1518 Jun 7 2013 aliases
-rw-r--r--. 1 root root 12288 Aug 27 05:10 aliases.db
drwxr-xr-x. 2 root root 51 Aug 27 04:51 alsa
drwxr-xr-x. 2 root root 4096 Aug 27 05:01 alternatives
-rw-------. 1 root root 541 Feb 23 2016 anacrontab
-rw-r--r--. 1 root root 55 Jun 6 2016 asound.conf
-rw-r--r--. 1 root root 1 May 23 2016 at.deny
drwxr-xr-x. 2 root root 32 Aug 27 04:53 at-spi2
drwxr-x---. 3 root root 43 Aug 27 04:51 audisp
drwxr-x---. 3 root root 83 Aug 27 05:10 audit
drwxr-xr-x. 4 root root 71 Aug 27 04:56 avahi
drwxr-xr-x. 2 root root 4096 Aug 27 04:57 bash_completion.d
-rw-r--r--. 1 root root 2853 May 4 2016 bashrc
drwxr-xr-x. 2 root root 6 Sep 13 2016 binfmt.d
drwxr-xr-x. 2 root root 23 Aug 27 04:50 bluetooth
drwxr-xr-x. 2 root root 42 Aug 27 04:48 bonobo-activation
drwxr-xr-x. 2 root root 12288 Aug 27 04:52 brltty
-rw-r--r--. 1 root root 21929 May 6 2016 brltty.conf
-rw-r--r--. 1 root root 676 Jun 23 2016 cgconfig.conf
drwxr-xr-x. 2 root root 6 Jun 23 2016 cgconfig.d
-rw-r--r--. 1 root root 234 Jun 23 2016 cgrules.conf
-rw-r--r--. 1 root root 131 Jun 23 2016 cgsnapshot_blacklist.conf
drwxr-xr-x. 2 root root 6 Jun 29 2016 chkconfig.d
-rw-r--r--. 1 root root 1157 Jun 28 2016 chrony.conf
-rw-r-----. 1 root chrony 9 Jun 28 2016 chrony.keys
drwxr-xr-x. 2 root root 26 Aug 27 04:56 cifs-utils
drwxr-xr-x. 2 root root 54 Aug 27 04:56 cron.d
drwxr-xr-x. 2 root root 70 Aug 27 04:56 cron.daily
-rw-------. 1 root root 0 Feb 23 2016 cron.deny
drwxr-xr-x. 2 root root 41 Aug 27 04:56 cron.hourly
drwxr-xr-x. 2 root root 6 Dec 28 2013 cron.monthly
-rw-r--r--. 1 root root 451 Dec 28 2013 crontab
drwxr-xr-x. 2 root root 6 Dec 28 2013 cron.weekly
-rw-------. 1 root root 0 Aug 27 04:46 crypttab
-rw-r--r--. 1 root root 1620 May 4 2016 csh.cshrc
-rw-r--r--. 1 root root 841 Jun 7 2013 csh.login
drwxr-xr-x. 5 root lp 4096 Aug 27 06:10 cups
drwxr-xr-x. 2 root root 34 Aug 27 04:52 cupshelpers
drwxr-xr-x. 4 root root 78 Aug 27 04:50 dbus-1
drwxr-xr-x. 4 root root 31 Aug 27 04:50 dconf
drwxr-xr-x. 2 root root 44 Aug 27 05:02 default
drwxr-xr-x. 2 root root 23 Aug 27 04:50 depmod.d
drwxr-x---. 3 root root 24 Aug 27 04:50 dhcp
-rw-r--r--. 1 root root 5090 Jun 30 2016 DIR_COLORS
-rw-r--r--. 1 root root 5725 Jun 30 2016 DIR_COLORS.256color
-rw-r--r--. 1 root root 4669 Jun 30 2016 DIR_COLORS.lightbgcolor
-rw-r--r--. 1 root root 1131 Jun 2 2015 dleyna-server-service.conf
-rw-r--r--. 1 root root 25213 Sep 13 2016 dnsmasq.conf
drwxr-xr-x. 2 root root 6 Sep 13 2016 dnsmasq.d
-rw-r--r--. 1 root root 1285 Oct 5 2016 dracut.conf
drwxr-xr-x. 2 root root 6 Oct 5 2016 dracut.conf.d
-rw-r--r--. 1 root root 4346 Aug 10 2016 drirc
-rw-r--r--. 1 root root 112 Jun 13 2016 e2fsck.conf
-rw-r--r--. 1 root root 4760 Jan 25 2014 enscript.cfg
-rw-r--r--. 1 root root 0 May 4 2016 environment
-rw-r--r--. 1 root root 1317 Jun 30 2016 ethertypes
-rw-r--r--. 1 root root 0 Jun 7 2013 exports
drwxr-xr-x. 2 root root 6 Aug 17 2016 exports.d
lrwxrwxrwx. 1 root root 56 Aug 27 04:48 favicon.png -> /usr/share/icons/hicolor/16x16/apps/fedora-logo-icon.png
drwxr-xr-x. 2 root root 22 Aug 27 04:51 fcoe
drwxr-xr-x. 2 root root 46 Aug 27 04:52 festival
-rw-r--r--. 1 root root 70 May 4 2016 filesystems
drwxr-xr-x. 3 root root 18 Aug 27 04:55 firefox
drwxr-x---. 5 root root 104 Aug 27 04:51 firewalld
drwxr-xr-x. 3 root root 38 Aug 27 04:48 fonts
-rw-r--r--. 1 root root 20 May 12 2014 fprintd.conf
-rw-r--r--. 1 root root 501 Aug 27 04:46 fstab
-rw-r--r--. 1 root root 38 May 19 2016 fuse.conf
drwxr-xr-x. 7 root root 107 Aug 27 04:50 gconf
drwxr-xr-x. 2 root root 6 Apr 10 2015 gcrypt
-rw-r--r--. 1 root root 265 Aug 4 2016 gdbinit
drwxr-xr-x. 2 root root 6 Aug 4 2016 gdbinit.d
drwxr-xr-x. 6 root root 107 Aug 27 04:54 gdm
drwxr-xr-x. 2 root root 26 Aug 27 04:51 geoclue
-rw-r--r--. 1 root root 842 Jun 29 2016 GeoIP.conf
-rw-r--r--. 1 root root 858 Jun 29 2016 GeoIP.conf.default
drwxr-xr-x. 3 root root 18 Aug 27 04:52 ghostscript
drwxr-xr-x. 3 root root 21 Aug 27 04:53 gnome-vfs-2.0
drwxr-xr-x. 2 root root 6 Mar 24 2016 gnupg
-rw-r--r--. 1 root root 94 Apr 29 2015 GREP_COLORS
drwxr-xr-x. 4 root root 40 Aug 27 04:48 groff
-rw-r--r--. 1 root root 962 Aug 27 05:02 group
-rw-r--r--. 1 root root 955 Aug 27 05:02 group-
lrwxrwxrwx. 1 root root 22 Aug 27 04:56 grub2.cfg -> ../boot/grub2/grub.cfg
drwx------. 2 root root 182 Aug 27 05:01 grub.d
----------. 1 root root 778 Aug 27 05:02 gshadow
----------. 1 root root 771 Aug 27 05:02 gshadow-
drwxr-xr-x. 3 root root 20 Aug 27 04:48 gss
drwxr-xr-x. 2 root root 27 Aug 27 04:51 gssproxy
-rw-r--r--. 1 root root 9 Jun 7 2013 host.conf
-rw-r--r--. 1 root root 12 Aug 27 05:02 hostname
-rw-r--r--. 1 root root 158 Jun 7 2013 hosts
-rw-r--r--. 1 root root 370 Jun 7 2013 hosts.allow
-rw-r--r--. 1 root root 460 Jun 7 2013 hosts.deny
drwxr-xr-x. 2 root root 24 Aug 27 04:51 hp
-rw-r--r--. 1 root root 3580 Aug 18 2016 idmapd.conf
lrwxrwxrwx. 1 root root 11 Aug 27 04:47 init.d -> rc.d/init.d
-rw-r--r--. 1 root root 511 Sep 12 2016 inittab
-rw-r--r--. 1 root root 942 Jun 7 2013 inputrc
drwxr-xr-x. 2 root root 140 Aug 27 04:48 iproute2
-rw-r--r--. 1 root root 2380 Sep 14 2016 ipsec.conf
drwx------. 3 root root 50 Aug 27 04:51 ipsec.d
-rw-------. 1 root root 31 Sep 14 2016 ipsec.secrets
drwxr-xr-x. 2 root root 52 Aug 27 04:50 iscsi
-rw-r--r--. 1 root root 23 Sep 27 2016 issue
-rw-r--r--. 1 root root 22 Sep 27 2016 issue.net
drwxr-xr-x. 3 root root 62 Aug 27 04:48 java
drwxr-xr-x. 2 root root 6 Jul 2 2015 jvm
drwxr-xr-x. 2 root root 6 Jul 2 2015 jvm-commmon
drwxr-xr-x. 5 root root 44 Aug 27 04:49 kde
-rw-r--r--. 1 root root 271 Jul 9 2008 kde4rc
-rw-r--r--. 1 root root 204 Jul 9 2008 kderc
-rw-r--r--. 1 root root 6920 Aug 27 04:51 kdump.conf
drwxr-xr-x. 3 root root 24 Aug 27 04:56 kernel
-rw-r--r--. 1 root root 590 Aug 19 2016 krb5.conf
drwxr-xr-x. 2 root root 6 Aug 19 2016 krb5.conf.d
-rw-r--r--. 1 root root 478 Sep 20 2016 ksmtuned.conf
-rw-r--r--. 1 root root 1174 May 8 2015 ksysguarddrc
-rw-r--r--. 1 root root 97053 Aug 27 05:01 ld.so.cache
-rw-r--r--. 1 root root 28 Feb 28 2013 ld.so.conf
drwxr-xr-x. 2 root root 151 Aug 27 04:53 ld.so.conf.d
-rw-r-----. 1 root root 191 Jul 14 2016 libaudit.conf
drwxr-xr-x. 2 root root 6 Jul 20 2016 libibverbs.d
drwxr-xr-x. 2 root root 35 Aug 27 04:47 libnl
drwxr-xr-x. 6 root root 149 Aug 27 04:49 libreport
-rw-r--r--. 1 root root 2391 Oct 13 2013 libuser.conf
drwx------. 4 root root 184 Aug 27 04:52 libvirt
-rw-r--r--. 1 root root 19 Aug 27 05:02 locale.conf
lrwxrwxrwx. 1 root root 35 Aug 27 05:02 localtime -> ../usr/share/zoneinfo/Asia/Shanghai
-rw-r--r--. 1 root root 2028 Jun 28 2016 login.defs
-rw-r--r--. 1 root root 662 Jul 31 2013 logrotate.conf
drwxr-xr-x. 2 root root 244 Aug 27 04:56 logrotate.d
drwxr-xr-x. 3 root root 43 Aug 27 04:50 lsm
drwxr-xr-x. 6 root root 100 Aug 27 04:51 lvm
-r--r--r--. 1 root root 33 Aug 27 04:50 machine-id
-rw-r--r--. 1 root root 111 Jun 27 2016 magic
-rw-r--r--. 1 root root 272 May 15 2013 mailcap
-rw-r--r--. 1 root root 1968 Dec 10 2014 mail.rc
-rw-r--r--. 1 root root 5122 Sep 5 2016 makedumpfile.conf.sample
-rw-r--r--. 1 root root 5171 Mar 18 2014 man_db.conf
drwxr-xr-x. 2 root root 6 Jul 2 2015 maven
drwxr-xr-x. 3 root root 61 Aug 27 04:56 mcelog
-rw-r--r--. 1 root root 51787 May 15 2013 mime.types
-rw-r--r--. 1 root root 936 Jun 13 2016 mke2fs.conf
drwxr-xr-x. 2 root root 59 Aug 27 04:56 modprobe.d
drwxr-xr-x. 2 root root 6 Sep 13 2016 modules-load.d
-rw-r--r--. 1 root root 0 Jun 7 2013 motd
lrwxrwxrwx. 1 root root 17 Aug 27 04:46 mtab -> /proc/self/mounts
-rw-r--r--. 1 root root 2620 Jan 27 2014 mtools.conf
drwxr-xr-x. 2 root root 6 Sep 8 2016 multipath
-rw-r--r--. 1 root root 570 Sep 21 2016 my.cnf
drwxr-xr-x. 2 root root 67 Aug 27 04:51 my.cnf.d
-rw-r--r--. 1 root root 8892 Jan 27 2014 nanorc
-rw-r--r--. 1 root root 767 Jun 6 2016 netconfig
drwxr-xr-x. 8 root root 145 Aug 27 04:51 NetworkManager
-rw-r--r--. 1 root root 58 Sep 12 2016 networks
-rw-r--r--. 1 root root 3390 Aug 17 2016 nfsmount.conf
-rw-r--r--. 1 root root 1728 Aug 27 05:02 nsswitch.conf
-rw-r--r--. 1 root root 1726 Oct 22 2012 nsswitch.conf.bak
drwxr-xr-x. 2 root root 38 Aug 27 04:56 ntp
-rw-r--r--. 1 root root 91 Dec 3 2012 numad.conf
drwxr-xr-x. 2 root root 6 Sep 10 2014 oddjob
-rw-r--r--. 1 root root 4922 Sep 10 2014 oddjobd.conf
drwxr-xr-x. 2 root root 70 Aug 27 04:51 oddjobd.conf.d
drwxr-xr-x. 3 root root 36 Aug 27 04:49 openldap
drwxr-xr-x. 2 root root 6 Mar 10 2016 opt
-rw-r--r--. 1 root root 495 Sep 27 2016 os-release
drwxr-xr-x. 2 root root 92 Aug 27 04:56 PackageKit
drwxr-xr-x. 2 root root 4096 Aug 27 05:02 pam.d
-rw-r--r--. 1 root root 2254 Aug 27 05:02 passwd
-rw-r--r--. 1 root root 2254 Aug 27 05:02 passwd-
-rw-r--r--. 1 root root 1362 Jan 27 2014 pbm2ppa.conf
-rw-r--r--. 1 root root 2872 Jan 27 2014 pinforc
drwxr-xr-x. 3 root root 21 Aug 27 04:47 pkcs11
drwxr-xr-x. 13 root root 171 Aug 27 05:10 pki
drwxr-xr-x. 2 root root 28 Aug 27 04:52 plymouth
drwxr-xr-x. 5 root root 52 Aug 27 04:47 pm
-rw-r--r--. 1 root root 6300 Jan 27 2014 pnm2ppa.conf
drwxr-xr-x. 5 root root 72 Aug 27 04:50 polkit-1
drwxr-xr-x. 2 root root 6 Jan 27 2014 popt.d
drwxr-xr-x. 2 root root 154 Aug 27 04:56 postfix
drwxr-xr-x. 3 root root 219 Aug 27 04:50 ppp
drwxr-xr-x. 2 root root 105 Aug 27 04:51 prelink.conf.d
-rw-r--r--. 1 root root 233 Jun 7 2013 printcap
-rw-r--r--. 1 root root 1795 May 4 2016 profile
drwxr-xr-x. 2 root root 4096 Aug 27 04:56 profile.d
-rw-r--r--. 1 root root 6545 Jun 7 2013 protocols
drwxr-xr-x. 2 root root 79 Aug 27 04:52 pulse
drwxr-xr-x. 2 root root 23 Aug 27 04:52 purple
drwxr-xr-x. 2 root root 35 Aug 27 04:48 python
drwxr-xr-x. 3 root root 50 Aug 27 04:56 qemu-ga
drwxr-xr-x. 2 root root 51 Aug 27 04:53 qemu-kvm
-rw-r--r--. 1 root root 433 Aug 17 2015 radvd.conf
drwxr-xr-x. 3 root root 27 Aug 27 04:56 ras
lrwxrwxrwx. 1 root root 10 Aug 27 04:47 rc0.d -> rc.d/rc0.d
lrwxrwxrwx. 1 root root 10 Aug 27 04:47 rc1.d -> rc.d/rc1.d
lrwxrwxrwx. 1 root root 10 Aug 27 04:47 rc2.d -> rc.d/rc2.d
lrwxrwxrwx. 1 root root 10 Aug 27 04:47 rc3.d -> rc.d/rc3.d
lrwxrwxrwx. 1 root root 10 Aug 27 04:47 rc4.d -> rc.d/rc4.d
lrwxrwxrwx. 1 root root 10 Aug 27 04:47 rc5.d -> rc.d/rc5.d
lrwxrwxrwx. 1 root root 10 Aug 27 04:47 rc6.d -> rc.d/rc6.d
drwxr-xr-x. 10 root root 127 Aug 27 04:50 rc.d
lrwxrwxrwx. 1 root root 13 Aug 27 04:50 rc.local -> rc.d/rc.local
drwxr-xr-x. 2 root root 57 Aug 27 04:51 rdma
drw-------. 2 root root 238 Aug 27 04:51 redhat-access-insights
-rw-r--r--. 1 root root 52 Sep 27 2016 redhat-release
-rw-r--r--. 1 root root 1787 Jan 26 2014 request-key.conf
drwxr-xr-x. 2 root root 30 Aug 27 04:52 request-key.d
-rw-r--r--. 1 root root 68 Aug 27 05:10 resolv.conf
drwxr-xr-x. 5 root root 86 Aug 27 04:52 rhsm
-rw-r--r--. 1 root root 1634 Dec 25 2012 rpc
drwxr-xr-x. 2 root root 4096 Aug 27 04:51 rpm
-rw-r--r--. 1 root root 458 Jun 24 2015 rsyncd.conf
-rw-r--r--. 1 root root 3232 Jul 14 2016 rsyslog.conf
drwxr-xr-x. 2 root root 25 Jul 14 2016 rsyslog.d
-rw-r--r--. 1 root root 928 Sep 12 2016 rwtab
drwxr-xr-x. 2 root root 23 Sep 12 2016 rwtab.d
drwxr-xr-x. 2 root root 61 Aug 27 04:50 samba
drwxr-xr-x. 3 root root 4096 Aug 27 04:53 sane.d
drwxr-xr-x. 2 root root 65 Aug 27 04:56 sasl2
drwxr-xr-x. 3 root root 34 Aug 27 04:57 scl
-rw-------. 1 root root 221 May 4 2016 securetty
drwxr-xr-x. 6 root root 4096 Aug 27 04:48 security
drwxr-xr-x. 5 root root 81 Aug 27 04:50 selinux
-rw-r--r--. 1 root root 670293 Jun 7 2013 services
-rw-r--r--. 1 root root 216 Aug 26 2016 sestatus.conf
drwxr-xr-x. 2 root root 33 Aug 27 04:51 setroubleshoot
drwxr-xr-x. 2 root root 4096 Aug 27 04:56 setuptool.d
drwxr-xr-x. 3 root root 4096 Aug 27 04:49 sgml
----------. 1 root root 1256 Aug 27 05:02 shadow
----------. 1 root root 1261 Aug 27 05:02 shadow-
-rw-r--r--. 1 root root 95 Aug 27 04:56 shells
drwxr-xr-x. 3 root root 78 Aug 27 04:47 skel
drwxr-xr-x. 3 root root 74 Aug 27 04:56 smartmontools
-rw-r--r--. 1 root root 100 Sep 9 2016 sos.conf
drwxr-xr-x. 3 root root 20 Aug 27 04:53 sound
drwxr-xr-x. 4 root root 56 Aug 27 04:53 speech-dispatcher
drwxr-xr-x. 2 root root 225 Aug 27 05:10 ssh
drwxr-xr-x. 2 root root 19 Aug 27 04:48 ssl
-rw-r--r--. 1 root root 212 Sep 12 2016 statetab
drwxr-xr-x. 2 root root 6 Sep 12 2016 statetab.d
-rw-r--r--. 1 root root 0 May 4 2016 subgid
-rw-r--r--. 1 root root 0 May 4 2016 subuid
drwxr-xr-x. 2 root root 6 Aug 13 2015 subversion
-rw-r-----. 1 root root 1786 Jul 19 2016 sudo.conf
-r--r-----. 1 root root 3907 Jul 19 2016 sudoers
drwxr-x---. 2 root root 6 Jul 19 2016 sudoers.d
-rw-r-----. 1 root root 3181 Jul 19 2016 sudo-ldap.conf
drwxr-xr-x. 7 root root 4096 Aug 27 05:10 sysconfig
-rw-r--r--. 1 root root 449 Sep 12 2016 sysctl.conf
drwxr-xr-x. 2 root root 28 Aug 27 04:50 sysctl.d
drwxr-xr-x. 4 root root 151 Aug 27 04:50 systemd
lrwxrwxrwx. 1 root root 14 Aug 27 04:47 system-release -> redhat-release
-rw-r--r--. 1 root root 45 Sep 27 2016 system-release-cpe
-rw-------. 1 tss tss 7046 May 25 2015 tcsd.conf
drwxr-xr-x. 2 root root 6 Jan 27 2014 terminfo
drwxr-xr-x. 2 root root 6 Sep 13 2016 tmpfiles.d
-rw-r--r--. 1 root root 45 May 10 2012 Trolltech.conf
-rw-r--r--. 1 root root 375 Sep 26 2016 trusted-key.key
drwxr-xr-x. 2 root root 70 Aug 27 04:56 tuned
drwxr-xr-x. 3 root root 54 Aug 27 05:10 udev
drwxr-xr-x. 2 root root 6 Jul 2 2015 udisks2
drwxr-xr-x. 2 root root 68 Aug 27 04:50 unbound
-rw-r--r--. 1 root root 513 Feb 4 2016 updatedb.conf
drwxr-xr-x. 2 root root 25 Aug 27 04:50 UPower
-rw-r--r--. 1 root root 1018 Jul 25 2016 usb_modeswitch.conf
-rw-r--r--. 1 root root 37 Aug 27 05:02 vconsole.conf
-rw-r--r--. 1 root root 1982 Jan 30 2014 vimrc
-rw-r--r--. 1 root root 1982 Jan 30 2014 virc
drwxr-xr-x. 2 root root 26 Aug 27 04:49 virtuoso
drwxr-xr-x. 4 root root 198 Aug 27 04:51 vmware-tools
-rw-r--r--. 1 root root 4479 Jun 21 2016 wgetrc
drwxr-xr-x. 2 root root 33 Aug 27 04:50 wpa_supplicant
-rw-r--r--. 1 root root 0 Jan 28 2014 wvdial.conf
drwxr-xr-x. 6 root root 103 Aug 27 04:52 X11
drwxr-xr-x. 6 root root 114 Aug 27 04:52 xdg
drwxr-xr-x. 2 root root 6 Mar 10 2016 xinetd.d
drwxr-xr-x. 2 root root 21 Aug 27 04:48 xml
drwxr-xr-x. 6 root root 100 Aug 27 04:50 yum
-rw-r--r--. 1 root root 813 Sep 19 2016 yum.conf
drwxr-xr-x. 2 root root 6 Sep 19 2016 yum.repos.d
[root@marklin ~]#
使用ls -ld+文件目录：查看具体某一个文件
[root@marklin ~]# ls -ld /etc
drwxr-xr-x. 143 root root 8192 Aug 27 05:10 /etc
[root@marklin ~]#
使用ls -lh+文件目录 ：方便阅读
[root@marklin ~]# ls -lh /etc
drwxr-xr-x. 143 root root 8192 Aug 27 05:10 /etc
[root@marklin ~]#
.:当前目录
..:父级目录，上层目录
linux目录文件有不同的颜色，不同颜色代表的意思：
颜色 名称 实例
蓝色 目录 /etc
黑色 文件 /etc/passwd
浅蓝色 链接 /etc/grub2.cfg
红色 压缩包 boot.tar.gz
绿色 可执行文件 /etc/init.d/network
黑底黄字 设备文件 /dev/sda
pwd命令：
作用：查看当前目录
语法：pwd 没有参数
[root@marklin ~]# pwd
/root
cd 命令：
作用：切换目录
语法：cd+目录名
#cd 回到用户自己主目录
[root@marklin Desktop]# cd
[root@marklin ~]#
#cd ~ 回到用户自己的主目录
[root@marklin ~]# cd
[root@marklin ~]#
#cd /etcsysconfig 和#cd /etc/sysconfig 一样
#cd /etc/ 和#cd /etc 一样
使date查看当前时间：
[root@marklin ~]# date
Sun Aug 27 06:32:09 CST 2017
使用hwclock查看bios硬件时间：
[root@marklin ~]# hwclock
Sun 27 Aug 2017 06:33:58 AM CST -1.027048 seconds
[root@marklin ~]#
在rhel6以前，系统时间和硬件时间bios时间是不一样的，因为时差，差8小时
操作系统会以bios时间为系统比哦啊准时间
帮助参数-h 和--help：
date --help 和date -h ：查看date 帮助文档
[root@marklin ~]# date --help
Usage: date [OPTION]... [+FORMAT]
or: date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
Display the current time in the given FORMAT, or set the system date.
Mandatory arguments to long options are mandatory for short options too.
-d, --date=STRING display time described by STRING, not 'now'
-f, --file=DATEFILE like --date once for each line of DATEFILE
-I[TIMESPEC], --iso-8601[=TIMESPEC] output date/time in ISO 8601 format.
TIMESPEC='date' for date only (the default),
'hours', 'minutes', 'seconds', or 'ns' for date
and time to the indicated precision.
-r, --reference=FILE display the last modification time of FILE
-R, --rfc-2822 output date and time in RFC 2822 format.
Example: Mon, 07 Aug 2006 12:34:56 -0600
--rfc-3339=TIMESPEC output date and time in RFC 3339 format.
TIMESPEC='date', 'seconds', or 'ns' for
date and time to the indicated precision.
Date and time components are separated by
a single space: 2006-08-07 12:34:56-06:00
-s, --set=STRING set time described by STRING
-u, --utc, --universal print or set Coordinated Universal Time (UTC)
--help display this help and exit
--version output version information and exit
FORMAT controls the output. Interpreted sequences are:
%% a literal %
%a locale's abbreviated weekday name (e.g., Sun)
%A locale's full weekday name (e.g., Sunday)
%b locale's abbreviated month name (e.g., Jan)
%B locale's full month name (e.g., January)
%c locale's date and time (e.g., Thu Mar 3 23:05:25 2005)
%C century; like %Y, except omit last two digits (e.g., 20)
%d day of month (e.g., 01)
%D date; same as %m/%d/%y
%e day of month, space padded; same as %_d
%F full date; same as %Y-%m-%d
%g last two digits of year of ISO week number (see %G)
%G year of ISO week number (see %V); normally useful only with %V
%h same as %b
%H hour (00..23)
%I hour (01..12)
%j day of year (001..366)
%k hour, space padded ( 0..23); same as %_H
%l hour, space padded ( 1..12); same as %_I
%m month (01..12)
%M minute (00..59)
%n a newline
%N nanoseconds (000000000..999999999)
%p locale's equivalent of either AM or PM; blank if not known
%P like %p, but lower case
%r locale's 12-hour clock time (e.g., 11:11:04 PM)
%R 24-hour hour and minute; same as %H:%M
%s seconds since 1970-01-01 00:00:00 UTC
%S second (00..60)
%t a tab
%T time; same as %H:%M:%S
%u day of week (1..7); 1 is Monday
%U week number of year, with Sunday as first day of week (00..53)
%V ISO week number, with Monday as first day of week (01..53)
%w day of week (0..6); 0 is Sunday
%W week number of year, with Monday as first day of week (00..53)
%x locale's date representation (e.g., 12/31/99)
%X locale's time representation (e.g., 23:13:48)
%y last two digits of year (00..99)
%Y year
%z +hhmm numeric time zone (e.g., -0400)
%:z +hh:mm numeric time zone (e.g., -04:00)
%::z +hh:mm:ss numeric time zone (e.g., -04:00:00)
%:::z numeric time zone with : to necessary precision (e.g., -04, +05:30)
%Z alphabetic time zone abbreviation (e.g., EDT)
By default, date pads numeric fields with zeroes.
The following optional flags may follow '%':
- (hyphen) do not pad the field
_ (underscore) pad with spaces
0 (zero) pad with zeros
^ use upper case if possible
# use opposite case if possible
After any flags comes an optional field width, as a decimal number;
then an optional modifier, which is either
E to use the locale's alternate representations if available, or
O to use the locale's alternate numeric symbols if available.
Examples:
Convert seconds since the epoch (1970-01-01 UTC) to a date
$ date --date='@2147483647'
Show the time on the west coast of the US (use tzselect(1) to find TZ)
$ TZ='America/Los_Angeles' date
Show the local time for 9AM next Friday on the west coast of the US
$ date --date='TZ="America/Los_Angeles" 09:00 next Fri'
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'date invocation'
[root@marklin ~]#
fdisk -- help fdisk -h：
[root@marklin ~]# data -h
bash: data: command not found...
[root@marklin ~]# date --help
Usage: date [OPTION]... [+FORMAT]
or: date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]
Display the current time in the given FORMAT, or set the system date.
Mandatory arguments to long options are mandatory for short options too.
-d, --date=STRING display time described by STRING, not 'now'
-f, --file=DATEFILE like --date once for each line of DATEFILE
-I[TIMESPEC], --iso-8601[=TIMESPEC] output date/time in ISO 8601 format.
TIMESPEC='date' for date only (the default),
'hours', 'minutes', 'seconds', or 'ns' for date
and time to the indicated precision.
-r, --reference=FILE display the last modification time of FILE
-R, --rfc-2822 output date and time in RFC 2822 format.
Example: Mon, 07 Aug 2006 12:34:56 -0600
--rfc-3339=TIMESPEC output date and time in RFC 3339 format.
TIMESPEC='date', 'seconds', or 'ns' for
date and time to the indicated precision.
Date and time components are separated by
a single space: 2006-08-07 12:34:56-06:00
-s, --set=STRING set time described by STRING
-u, --utc, --universal print or set Coordinated Universal Time (UTC)
--help display this help and exit
--version output version information and exit
FORMAT controls the output. Interpreted sequences are:
%% a literal %
%a locale's abbreviated weekday name (e.g., Sun)
%A locale's full weekday name (e.g., Sunday)
%b locale's abbreviated month name (e.g., Jan)
%B locale's full month name (e.g., January)
%c locale's date and time (e.g., Thu Mar 3 23:05:25 2005)
%C century; like %Y, except omit last two digits (e.g., 20)
%d day of month (e.g., 01)
%D date; same as %m/%d/%y
%e day of month, space padded; same as %_d
%F full date; same as %Y-%m-%d
%g last two digits of year of ISO week number (see %G)
%G year of ISO week number (see %V); normally useful only with %V
%h same as %b
%H hour (00..23)
%I hour (01..12)
%j day of year (001..366)
%k hour, space padded ( 0..23); same as %_H
%l hour, space padded ( 1..12); same as %_I
%m month (01..12)
%M minute (00..59)
%n a newline
%N nanoseconds (000000000..999999999)
%p locale's equivalent of either AM or PM; blank if not known
%P like %p, but lower case
%r locale's 12-hour clock time (e.g., 11:11:04 PM)
%R 24-hour hour and minute; same as %H:%M
%s seconds since 1970-01-01 00:00:00 UTC
%S second (00..60)
%t a tab
%T time; same as %H:%M:%S
%u day of week (1..7); 1 is Monday
%U week number of year, with Sunday as first day of week (00..53)
%V ISO week number, with Monday as first day of week (01..53)
%w day of week (0..6); 0 is Sunday
%W week number of year, with Monday as first day of week (00..53)
%x locale's date representation (e.g., 12/31/99)
%X locale's time representation (e.g., 23:13:48)
%y last two digits of year (00..99)
%Y year
%z +hhmm numeric time zone (e.g., -0400)
%:z +hh:mm numeric time zone (e.g., -04:00)
%::z +hh:mm:ss numeric time zone (e.g., -04:00:00)
%:::z numeric time zone with : to necessary precision (e.g., -04, +05:30)
%Z alphabetic time zone abbreviation (e.g., EDT)
By default, date pads numeric fields with zeroes.
The following optional flags may follow '%':
- (hyphen) do not pad the field
_ (underscore) pad with spaces
0 (zero) pad with zeros
^ use upper case if possible
# use opposite case if possible
After any flags comes an optional field width, as a decimal number;
then an optional modifier, which is either
E to use the locale's alternate representations if available, or
O to use the locale's alternate numeric symbols if available.
Examples:
Convert seconds since the epoch (1970-01-01 UTC) to a date
$ date --date='@2147483647'
Show the time on the west coast of the US (use tzselect(1) to find TZ)
$ TZ='America/Los_Angeles' date
Show the local time for 9AM next Friday on the west coast of the US
$ date --date='TZ="America/Los_Angeles" 09:00 next Fri'
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
For complete documentation, run: info coreutils 'date invocation'
[root@marklin ~]# fdisk -h
Usage:
fdisk [options] <disk> change partition table
fdisk [options] -l <disk> list partition table(s)
fdisk -s <partition> give partition size(s) in blocks
Options:
-b <size> sector size (512, 1024, 2048 or 4096)
-c[=<mode>] compatible mode: 'dos' or 'nondos' (default)
-h print this help text
-u[=<unit>] display units: 'cylinders' or 'sectors' (default)
-v print program version
-C <number> specify the number of cylinders
-H <number> specify the number of heads
-S <number> specify the number of sectors per track
[root@marklin ~]#
man find：
关机命令：
shutdown init reboot poweroff
Lan：局域网
VXLAN：用在openstack 多个局域网
shutdown：
作用：关机，重启，定时关机
语法：shutdown [选项]
-r：=> 重启计算机
-h：=> 关机
-h+时间：=> 定时关机
shutdown -h ：定时关机
shutdown -h+10:10分钟之后关机
shutdown -h 时间:指定具体的时间定时关机
shutdown -h now:立即关机
shutdown -c : 取消定时关机
rhel 7个系统启动级别：
init 命令：
作用：切换系统运行级别
语法：init 0-6
7个系统启动级别：
0：系统停机模式,系统默认运行级别不能设置为0，否则不能正常启动，机器关闭
1：单用户模式,root权限。用于系统维护，禁止远程登录，就像Windows下的安全模式登录
2：多用户模式，没有nfs网络支持
3：完整的多用户模式：有nfs，登录只够进入控制命令行模式
4.系统未使用，保留一般不用，在特殊情况下用它来做一些事情
5：图形化模式，登陆之后进入图形化GUI模式
6:重启模式，默认级别不能设置为6，否则不能正常启动，运行init 6 机器就会重启
RHEL 6：
[root@marklin ~]# init 0
[root@marklin ~]# init 3
[root@marklin ~]# init 5
RHEL 7 不再使用etc/inittab 文件进行默认的启动级别配置
systemd使用比sysvinit的运行级别更为自由的target替代
第3级运行使用 multi-user.target替代
第4级运行使用 graphical.target替代
runlevel3.target 和runlevel5.target分别是 multi-user.target和graphical.target的符号连接
[root@marklin ~]#vim etc/inittab
运行第三级别：
[root@marklin ~]#systemctl isolate multi-user.target
或者：
[root@marklin ~]#systemctl isolate runlevel3.target
运行第五级别：
[root@marklin ~]#systemctl isolate graphical.target
或者：
[root@marklin ~]#systemctl isolate runlevel5.target
默认第三级别：
[root@marklin ~]#systemctl set-default multi-user.target
默认第五级别：
[root@marklin ~]#systemctl set-default graphical.target
查看默认启动级别：
[root@marklin ~]#systemctl get-default
runlevel:运行启动级别本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。
