linux

shell

su

# 发现进入root账户找不到sbin目录下的所有命令
# 使用su - 或者 su -l表示login shell继承环境变了PATH,PATH可以用export设置
su -l

#!

https://en.wikipedia.org/wiki/Shebang_(Unix)

It's a convention so the *nix shell knows what kind of interpreter to run

#!/bin/bash
#!/usr/bin/python
#!/bin/perl

alias

# 设置alias将mac上命令不同的名字设置为linux下的名字
# alias ldd='otool -L'
# alias brew='HOMEBREW_NO_AUTO_UPDATE=1 brew'
alias ls='ls -F --color=auto'
alias grep='grep --color=auto'

命令后台运行

nohup

nohup command &

setsid

setsid command &

disown

disown -h %1

subshell

(command &)

命令前后台切换

停止当前进程(ctrl + z)
查看所有进程(jobs)
切换到前台进程(fg)
切换到后台进程(bg)
演示例子

nc -lvp 1234 & # 命令后台执行
jobs # 查看后台执行命令编号
fg 1 # 将后台命令调到前台执行
ctrl + z # 停止当前进程
bg 1 # 将进程调到后台继续执行

命令历史查询

查看历史命令

history
history 5 # the last 5 commands

执行上一条命令

!!
!-1

执行具体命令

!+命令编号
!445

even more

https://www.digitalocean.com/community/tutorials/how-to-use-bash-history-commands-and-expansions-on-a-linux-vps

daemon

When a daemon starts up, it has to do some low-level housework to get itself ready for its real job

Fork off the parent process(init process with pid 0 is the new parent)
Change file mode mask (umask)
Open any logs for writing
Create a unique Session ID (SID)
Change the current working directory to a safe place
Close standard file descriptors
Enter actual daemon code

manager services(systemctl)

sudo systemctl disable geoclue.service
sudo systemctl mask geoclue.service # prohibit to /dev/null

network

remove virtual network interface

sudo ip link set dev outline-tun0 down

edit host file

# edit this file
vim /etc/hosts

nslookup(name server lookup)

# debian should install dnsutils
sudo apt install dnsutils

修改mac地址

# for MacOS
sudo ifconfig en0 ether d4:61:9d:32:3f:cf

# for linux
ip link set dev eth0 address XX:XX:XX:XX:XX:XX

恢复默认mac地址

ethtool -P eth0

package management(apt/yum)

https://www.debian.org/doc/manuals/debian-reference/ch02.en.html

permissions

root用户也无法删除只读文件，所以要先修改权限
root用户无法删除挂载的只读文件,修改权限也无法在挂载的文件上实现,要找到原文件的位置

# 执行mount命令,查看所有挂载
mount

/mnt vs /media

/media for system use
/mnt for user use
在debian上，如果mount到/media下的存储设备,gnome的filemanager是可以看到的 mount到其他位置上只有自己能看到

bash中单引号和双引号的区别

简单的说单引号包裹的内容不作变量解析、字符转义操作，只作为普通纯文本原样输出双引号包裹的内容会进行变量解析、字符转义等操作

enable/disable GUI

sudo systemctl set-default multi-user.target # disable GUI
sudo systemctl set-default graphical.target # enable GUI

nmcli(network manager) 需要安装

https://www.96boards.org/documentation/consumer/guides/wifi_commandline.md.html

创建一个新的wifi连接

# 显示可以连接的无线网
nmcli dev wifi list
# 连接wifi
nmcli dev wifi connect SSID_Name password wireless_password

static IP

nmcli con modify con_name ipv4.method manual ipv4.address 192.168.10.155/24

重启wifi

systemctl restart network-manager

其他命令

# text UI
nmtui
# 显示子命令帮助
nmcli con -h
nmcli dev -h
# 显示本机所有连接
nmcli con show
# 启用连接
nmcli con up WiFi
nmcli general status
nmcli device status

linux tty字体样式配置

sudo dpkg-reconfigure console-setup

console locales(UTF8字符配置)

默认tty不能显示中文

# 安装
sudo apt-get install fbterm
# 启动
fbterm

# add to ~/.bashrc to automatically start
fbterm &>/dev/null

usb device descriptor error -71

关机后再开机(重启无效)

Tmux(terminal multiplexer)

terminal 分屏必用神器

支持鼠标操作

~/.tmux.conf

set -g mouse on

Mac系统下复制内容

fn加鼠标拖动选中字符，然后正常cmd+c/cmd+v

/proc

# 相关配置路径
/proc/sys/
# 随机端口范围
/proc/sys/net/ipv4/ip_local_port_range
# 文件fd最大值
/proc/sys/fs/file-max

great tools

glances
sysbench
pstack
perf

JumHorn/linux

README