常用命令之Ubuntu命令

一、写在前

  作为一名运维工程师，我们需要接触的系统很多，Ubuntu近些年在人工智能的大趋势下，系统使用越来越广泛。Ubuntu与centos同为Linux操作系统，但是日常操作使用习惯中还是有些许不同的，对应的Ubuntu的命令也有部分有所不同。此博文主要是作为给笔记给自己留存和查阅。博文命令演示环境操作系统版本：Ubuntu 20.04.3 LTS。

二、Ubuntu常用命令示例

1、查看系统版本

root@s162:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal
root@s162:~# cat /etc/issue
Ubuntu 20.04.3 LTS \n \l

2、查看系统架构

root@s162:~# arch
x86_64
root@s162:~# uname -m
x86_64

3、查看内核版本

root@s162:~# cat /proc/version
Linux version 5.4.0-84-generic (buildd@lgw01-amd64-050) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #94-Ubuntu SMP Thu Aug 26 20:27:37 UTC 2021
root@s162:~# uname -a
Linux s162 5.4.0-84-generic #94-Ubuntu SMP Thu Aug 26 20:27:37 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

4、查看shell环境变量

#ubuntu默认shell环境变量为dash，为了适配自己centos下的使用习惯，本环境修改为了bash。
root@s162:~# echo $SHELL
/bin/bash
root@s162:~# ll /bin/sh
lrwxrwxrwx 1 root root 4 Aug 24 08:42 /bin/sh -> dash*

5、创建普通用户

#ubuntu添加用户默认不会创建home目录，默认为dash，如果需要创建home目录需要使用-m参数，-s参数指定$SHELL环境。
root@s162:~# useradd test1 -m -s /bin/bash

6、查看IP地址

root@s162:~# ip addr
root@s162:~# ifconfig

8、安装软件

#dpkg安装类似于centos的rpm安装。
root@s162:/opt# dpkg -i cuda-repo-ubuntu1804-11-4-local_11.4.1-470.57.02-1_amd64.deb
#apt-get安装类似于centos的yum安装。
root@s162:~# apt-get install -y net-tools
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following NEW packages will be installed:
net-tools
0 upgraded, 1 newly installed, 0 to remove and 4 not upgraded.
Need to get 0 B/196 kB of archives.
After this operation, 864 kB of additional disk space will be used.
Selecting previously unselected package net-tools.
(Reading database … 149206 files and directories currently installed.)
Preparing to unpack …/net-tools_1.60+git20180626.aebd88e-1ubuntu1_amd64.deb …
Unpacking net-tools (1.60+git20180626.aebd88e-1ubuntu1) …
Setting up net-tools (1.60+git20180626.aebd88e-1ubuntu1) …
Processing triggers for man-db (2.9.1-1) …

9、查看已安装包

root@s162:/opt# dpkg -l |grep net-tools
ii net-tools 1.60+git20180626.aebd88e-1ubuntu1 amd64 NET-3 networking toolkit
root@s162:/opt# apt list --installed |grep net-tools

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

net-tools/focal,now 1.60+git20180626.aebd88e-1ubuntu1 amd64 [installed]

10、卸载软件包

root@s162:/opt# apt-get purge vim
root@s162:/opt# dpkg -P vim
root@s162:/opt# dpkg -r vim

11、系统启动级别查看和管理

#系统启动级别查看和管理与centos 7一致。
root@s162:/opt# systemctl get-default
graphical.target
root@s162:/opt# systemctl set-default multi-user.target
Created symlink /etc/systemd/system/default.target → /lib/systemd/system/multi-user.target.
root@s162:/opt# systemctl set-default graphical.target
Removed /etc/systemd/system/default.target.
Created symlink /etc/systemd/system/default.target → /lib/systemd/system/graphical.target.

12、时区设置

root@s162:/opt# dpkg-reconfigure tzdata

Current default time zone: ‘Asia/Shanghai’
Local time is now: Wed Sep 15 10:55:42 CST 2021.
Universal Time is now: Wed Sep 15 02:55:42 UTC 2021.

13、查看和修改主机名

root@s162:/opt# hostname
s162
root@s162:/opt# hostnamectl set-hostname u162
root@s162:/opt# cat /etc/hostname
u162
#修改主机名后hosts文件不会随之变化，需要手动修改
root@s162:/opt# vim /etc/hosts

14、修改root密码

#Ubuntu初始安装完成后设置了一个普通用户，root账户为随机密码，可以使用sudo命令修改root密码。
ubuntu@s162:~$ sudo passwd root
[sudo] password for ubuntu:
New password:
Retype new password:
passwd: password updated successfully