Rhel 7.3 基本操作-白红宇

Rhel 7.3 基本操作

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发布时间：2019-06-18

本文共 28893 字，大约阅读时间需要 96 分钟。

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 ~]# whoami

root

使用who am i 查询当前终端对应的

[root ~]# who am i

root pts/0 2017-08-27 05:13 (:0)

[root ~]#

使用w查看pts的进程：

[root ~]# 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 ~]#

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 ~]#

[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

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：