Linux basic commands



Shutdown and restart commands

Shutdown
#-H shutdown,-r restart;-C to cancel the previous shutdown command;-now immediately shut down the machine

Halt
Poweroff
Init 0

Restart
Reboot
Init 6

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File processing commands

mkdir Directory
#-P Parent directory does not exist in case of Mister into parent directory

CP original file or directory destination file
#-R copy directory;-p reserved file attributes;

ln Original File Destination file

MV Original File destination directory
#功能描述: Moving files, renaming files

Cat FileName
#-N Displays line numbers

TAC FileName
#反向列示文件内容

Less fileName
#分页显示文件的内容 (can page UP)

Head FileName
#显示文件前面几行
#-n Specifies the number of rows

Tail FileName
#显示文件的后面几行
#-n Specifies the number of rows;-f dynamically displays the end of the file

WC FileName
#统计文本文档的行数, number of words, characters, WC (word count)
#-C Statistics bytes;-l counts the number of rows;-m counts characters and cannot be used in conjunction with-C; A word is defined as a string separated by a blank, a jump, or a newline character.

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File Search Command

Find [Search Range] [match condition]
Example: Find/home/jxn-name man search for a file or directory named man starting from a specified directory

grep [Specify string] FileName
#在文件中搜寻字串匹配的行并输出,-I is not case-sensitive, and-V excludes the specified string (reverse lookup);--color=auto search keywords are displayed in color

Whereis command
#搜索命令所在目录及帮助文档路径

which command
#搜索命令所在目录及别名信息

Locate FileName
#在文件资料库中查找文件

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Configuration file

/etc/profile: System Global Environment settings and startup programs

/ETC/BASHRC: System-defined functions and command aliases

/ETC/INPUTRC: Settings related to keyboard and input

/$HOME/.bash_profile: User's environment setting and startup program

/$HOME/.BASHRC: User-defined functions and command aliases

/$HOME/.bash_history: The History of the shell command executed by the user

/$HOME/.bash_logout: Executes the file when the user logs off

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Account System Files

/etc/password
#用户信息文件, the root user has a UID of 0

/etc/shadow
#用户密码文件

/etc/group
#组信息文件

/etc/gshadow
#组密码文件

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User and Group Management commands

Useradd UserName
#添加用户,-p password;-d home directory name;-g group name;-s shell path;-U set UID number

Usermod UserName
#修改用户信息,-p new password;-g new group name;-l new login name;-d home directory name;-U new UID number

Userdel UserName
#删除用户,-R deletes the user's home directory while deleting the user

passwd UserName
#修改密码,--stdin the data as the user's password through the pipe character;-d delete the account password;

Groupadd GroupName
#添加新组, the GID of the-G setting group

Groupmod GroupName
#修改组信息,-N Change the name of the group account;-G new GID

Groupdel GroupName
#删除组

W.H.O.
#查看登录用户的信息

W
#查看登录用户的详细信息

ID UserName
#查看用户的UID, GID

Groups username
#显示用户所属组

Su UserName
#切换用户,-Indicates that the user's environment variable is switched at the same time;-C uses only that user to execute a command without switching user identities

Chage UserName
#修改用户密码状态

chmod fileName
#修改操作权限, the group user, o other user, a all user of the group of Master, G owner;
#+ permissions,-minus permissions, = Plus permissions to delete the original permissions, R (4), W (2), X (1) Read, write, execute permissions
Example: chmod u+x fileName

Chown Owner[:group] File or directory
#更改文件的属主或属主所在的组,-R processes all files under the specified directory and directory;
Example: Change directory: Chown-r jxn:student/tmp/src change file: Chown jxn Test.java

Chgrp
#修改文件或目录所属群组 (Note: The owner cannot be modified)

Chgrp-r groupname/tmp/all the subdirectories and files in the TMP directory are all set to GroupName

Umask
#显示, setting default permissions for files
#-S Displays the new file default permissions in rwx form

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File System Management

Mount [-t file system] device file name mount point
#挂载命令
#ext2 Linux currently used in the file system; Msdos MS-DOS fat, is fat16;vfat u disk and windows98 commonly used FAT32; NFS Network File system
ISO9660 CD-ROM standard file system

DF Mount point
#查看文件系统磁盘空间的使用情况,-a displays all file system information;-H uses the display capacity of KB, MB, GB and so on;-T displays the file system type,-K,-M in KB, MB display capacity

Du directory or file name
#显示指定的文件或目录已使用的磁盘空间的总量,-a displays the disk footprint of each sub-file;-S statistics total usage, not subdirectories and sub-files,-H Ibid

Fdisk-l
#查看硬盘列表

Fdisk/dev/sdb
#使用fdisk命令分区

#fdisk交互指令说明

Command description
A to set the bootable tag
b Edit BSD Disk label
C Set DOS operating system compatibility tag
D Delete a partition
L Displays the known file system type. 82 for Linux swap partitions, 83 for Linux partitions
M Display Help Menu
N New Partition
o Create a blank DOS partition table
P Show Partition list
Q Do not save exit
s new Blank Sun disk label
T change the system ID of a partition
U Change Display recording Unit
V Verify partition Table
W Save exit
X additional features (experts only)

Mkfs-t EXT4/DEV/SDB1
#格式化分区

Fsch Partition Device file name
#修复文件系统

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System administration Commands

Stat
#显示文件的相关信息, more detailed than the LS command display

W.H.O.
#显示在线登录用户

WhoAmI
#显示用户自己的身份

Hostname
#显示主机名称

Uname
#显示系统信息

Top
#系统监视器 (equivalent to Task Manager under Windows), showing the most resource-intensive processes in the current system

Ps
#显示瞬间的进程状态

Kill
#杀死进程

Free
#显示当前内存和交换空间的使用情况

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Network commands

Ping IP Address
#测试网络连通性,-c specifies the number of times to send

Ifconfig NIC name IP address
#查看和设置网络接口 (NIC) information, Ifconfig (interface Configure)

Last
#列出目前与过去登入系统的用户信息

Netstat
#显示网络相关信息,-t TCP protocol;-u UDP protocol;-L listener;-R Route;-N Displays IP address and port number

Setup
#配置网络

Mail UserName
#查看发送电子邮件

Write UserName
#给用户发信息, save end with Ctrl+d

Wall message
#发广播信息, Wall (that is, write all)

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Help commands

Man command or configuration file
Help command

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Bash common shortcut keys

CTRL + C forces the current command to terminate.
Ctrl+l clear screen, equivalent to the clear command.
Ctrl+u the command before the cursor is deleted or clipped.
Ctrl+y Paste the contents of Ctrl+u or ctrl+k cut.
Ctrl+r Search in the history command, after pressing CTRL+R, the search interface will appear, as long as the search content is entered, it will be searched from the history command.
Ctrl+d exit the current terminal.

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Linux basic commands