1. yum

• yum源：Linux下载软件 软件仓库
  • 默认yum源：随机地方 修改yum源为指定的网站
  • 增加新的yum源：epel源

[root@oldboyedu ~]# ll /etc/yum.repos.d/
total 32
-rw-r--r--. 1 root root 1664 Nov 23 2018 CentOS-Base.repo
-rw-r--r--. 1 root root 1309 Nov 23 2018 CentOS-CR.repo
-rw-r--r--. 1 root root 649 Nov 23 2018 CentOSDebuginfo.
repo
-rw-r--r--. 1 root root 314 Nov 23 2018 CentOSfasttrack.
repo
-rw-r--r--. 1 root root 630 Nov 23 2018 CentOS-Media.repo
-rw-r--r--. 1 root root 1331 Nov 23 2018 CentOS-Sources.repo
-rw-r--r--. 1 root root 5701 Nov 23 2018 CentOS-Vault.repo
[root@oldboyedu ~]# cat /etc/yum.repos.d/CentOS-Base.repo
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the
client and the
# update status of each mirror to pick mirrors that are
updated to and
# geographically close to the client. You should use this
for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back
you can try the
# remarked out baseurl= line instead.
#
#
#mirrorlist 下载地址
[base]
name=CentOS-$releasever - Base
mirrorlist=http://mirrorlist.centos.org/?
release=$releasever&arch=$basearch&repo=os&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/os/$base
arch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates
mirrorlist=http://mirrorlist.centos.org/?
release=$releasever&arch=$basearch&repo=updates&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/updates/
$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
mirrorlist=http://mirrorlist.centos.org/?
release=$releasever&arch=$basearch&repo=extras&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$
basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing
packages
[centosplus]
name=CentOS-$releasever - Plus
mirrorlist=http://mirrorlist.centos.org/?
release=$releasever&arch=$basearch&repo=centosplus&infra=$inf
ra
#baseurl=http://mirror.centos.org/centos/$releasever/centospl
us/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

• 把系统当前的yum源修改为从清华/阿里云下载

#查看Linux当前使用的yum源是什么?
[root@oldboyedu ~]# yum repolist
Loaded plugins: fastestmirror
Determining fastest mirrors
* base: mirrors.tuna.tsinghua.edu.cn
* extras: mirrors.tuna.tsinghua.edu.cn
* updates: mirrors.tuna.tsinghua.edu.cn
base | 3.6 kB
00:00:00
extras | 2.9 kB
00:00:00
updates | 2.9 kB
00:00:00
(1/4): base/7/x86_64/group_gz | 165 kB
00:00:00
(2/4): extras/7/x86_64/primary_db | 153 kB
00:00:00
(3/4): updates/7/x86_64/primary_db | 5.9 MB
00:00:02
(4/4): base/7/x86_64/primary_db | 6.0 MB
00:00:02
repo id repo name
status
base/7/x86_64 CentOS-7 - Base
10,097
extras/7/x86_64 CentOS-7 - Extras
307
updates/7/x86_64 CentOS-7 - Updates
1,010
repolist: 11,414

• 修改为从阿里云下载软件

http://mirrors.aliyun.com/

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOSBase.
repo.backup
#
wget curl 用于下载软件
wget centos 7 中 默认没有安装
curl -o /etc/yum.repos.d/CentOS-Base.repo
http://mirrors.aliyun.com/repo/Centos-7.repo
[root@oldboyedu ~]# yum repolist
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
repo id repo name
status
base/7/x86_64 CentOS-7 - Base - mirrors.aliyun.com
10,097
extras/7/x86_64 CentOS-7 - Extras - mirrors.aliyun.com
307
updates/7/x86_64 CentOS-7 - Updates - mirrors.aliyun.com
1,010
repolist: 11,414

• 增加epel源

curl -o /etc/yum.repos.d/epel.repo
http://mirrors.aliyun.com/repo/epel-7.repo
[root@oldboyedu ~]# yum repolist
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
repo id repo name
status
base/7/x86_64 CentOS-7 - Base -
mirrors.aliyun.com 10,097
epel/x86_64 Extra Packages for
Enterprise Linux 7 - x86_64 12,584
extras/7/x86_64 CentOS-7 - Extras -
mirrors.aliyun.com 307
updates/7/x86_64 CentOS-7 - Updates -
mirrors.aliyun.com 1,010
repolist: 23,998

2. Linux必备工具详解

• 必安装的工具
• yum install -y tree

tree vim wget bash-completion bash-completion-extras
lrzsz net-tools sysstat iotop iftop htop unzip nc nmap
telnet bc psmisc httpd-tools bind-utils nethogs cowsay sl
#删除linux下面 yum缓存
[root@oldboyedu ~]# yum clean all

3. 娱乐命令

[root@oldboyedu ~]# cowsay "列害了我的哥"
[root@oldboyedu ~]# animalsay "厉害了我的导"

4. 必备工具

#1. tree 以树形显示目录结构
## -L 2 显示目录中最多 几层内容
tree -L 1
[root@oldboyedu ~]# tree -L 1 /
/
├── bin -> usr/bin
├── boot
├── dataa
├── dev
├── etc
├── home
├── lib -> usr/lib
├── lib64 -> usr/lib64
├── lidao
├── media
├── mnt
├── oldboy
├── oldboy.tar.gz
├── opt
├── proc
├── root
├── run
├── sbin -> usr/sbin
├── srv
├── sys
├── tmp
├── usr
└── var
22 directories, 1 file
#2. vim vi升级版
#3. wget 下载指定的文件
wget www.baidu.com
#下载到指定目录 使用 -P 如果目录不存在 则wget自动创建
默认下载到当前目录
[root@oldboyedu ~]# wget -P
/oldwang/lidao/oldboy/alex/ddd/xxxx/oooo/ www.baidu.com
#4. 自动补全增强版
安装完成后 第1次使用需要重新登录(窗口 断开 重新连接)
bash-completion(默认源)自动补全增强工具,可以补全命令参数
bash-completion-extras(epel)自动补全超级增强工具,可以补全命令参数
#5. bc basic calc 计算器
## -l 显示带小数
[root@oldboyedu ~]# bc -l
bc 1.06.95
Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free
Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
1/3
.33333333333333333333
10/3
3.33333333333333333333
10+1-999*999/222
-4484.50000000000000000000
#6. lrzsz rz和sz
#7. htop
#8. nmap