Linux basic commands Collation (ii): Users, user groups, file systems, and networks

Linux common Commands (ii). txt
-----------users, user groups, file systems, and networks
First, the user's management
1. Management of the user
Useradd + "User name" new how users such as: Useradd dy
-P: Specify the user's password
-C: Make an annotated description
-D: Specify the directory where the user resides
-M: can be created with-m when the specified user directory does not exist
-G: Specifies the group to which the user belongs (primary group)
-G: Specify an additional group to which the user belongs
-S: Specify Shell files for user login
-U: Specify the user's user number
Usermod + "username" Modify user such as: usermod-s/bin/bash-d/home/z-G root DS (username)
Common options include-C,-D,-M,-G,-G,-S,-u, and-O, etc., which have the same meaning as the options in the Useradd command, specifying a new resource value for the user
Userdel + "User name" deletes the specified user
Userdel-r + "username" in deleting the specified user is to delete his working directory

2. Management of user passwords
passwd + "username" Modify user's password such as: passwd dy
-L: Lock password, i.e. disable account
-U: Password unlock
-D: No password for the account
-F: Force the next login is to modify the account
3. User's switch
Su + "user name"
Second, the user group management
1. Management of user groups
Groupadd: New User Group
-G: Set the group identification Number (GID) for the user group
-O: Commonly used with the-G option to indicate that the new user group ID can be the same as the GID of the user group already in the system
groupdel+ "user group name": Delete of user group
groupmod+ "user group name": Modification of user Group
The-g,-o parameter is the same as new
-N: Specify a new name for the user group
NEWGRP: Switch users to other user groups
Cat: Querying file contents

Third, the file system
Swapon-a: Turn on swap partition
Mount: Device mounted to a directory
-T: Specifies the file system type of the device
EXT4 Linux currently used file system
NFS Network File System
ISO9660 CD-ROM standard file system
Auto automatically detects the file system
-O: The option to mount the file system,
RO mount in read-only mode
RW in read/write mode
DF: List The overall practical situation of the file system
-A: List all file systems
-K: Display the file system in Kbytes capacity
? m: Display the file system in MBytes capacity
H:gbytes,mbytes,kbytes, etc. format self-display
-I: The number of inode displays
Du: Disk usage or directory capacity of the file system
-A: List all file system or directory usage
-H: Displayed in a more readable file format (g/m)
-S: Lists the total, not each individual directory occupancy capacity
-K: List capacity Display in Kbytes
-M: List capacity display in MBytes
DUMPE2FS: Observing the file system
-H: Lists only superblock data and does not list data from other segments
Iv. Network
Ifconfig: Display or set up network devices
wget +url: For downloading resources from the network
-O: Download and rename
--limit-rate: Speed limit Download
such as: wget-o newname--limit-rate=300k URL
-C: Breakpoint continued to pass
-B: Background download

Linux basic commands Collation (ii): Users, user groups, file systems, and networks