Common commands and server configurations in Linux

Common commands and server configurations for Linux systems-Linux Enterprise applications-Linux server applications. For more information, see the following. 1. Add User useradd command

Example:

# Useradd? M? G users? G wheel, sales? S/bin/tcsh? C "a user" myname

# Useradd-c "ftp Administrator"-d/var/ftp/-G ftpAdmin-s/sbin/nologin-r ftpAdmin

-M automatically creates the user's home directory and copies the framework directory (/etc/skel) file to the user directory.

-G: set the basic group in which the user is located.

-G adds the user to all comma-separated groups.

-S specifies the shell used.

-C description.

-D: set the main directory for the account.

-R system account. You do not need to create a home directory in/home.

The last one is the user name.

Ii. Specify the password passwd

Example: # passwd User Name

Enter the password.

3. delete user userdel

Example: # userdel Username

# Userdel? R user name

-R: Delete the home Directory (/home /.....)

Iv. File System commands

4.1 fdisk command

(1) fdisk? L: displays all partitions on the hard disk. Partition type (FAT32, Ext3 ).

(2) df? H: shows how the file system is mounted.

(3) fdisk/dev/hdb1: format the second IDE disk.

4.2 mount command mount the File System

(1) mount (no parameters are used) to view the system mounting status.

(2) mount/mnt/cdrom: mount the optical drive. You can use the cd/mnt/cdrom and then ls to view the content on the optical drive.

(3) mount/mnt/floppy: mount a floppy disk. You can use cd/mnt/floppy to check the content on the floppy disk.

In steps 2 and 3, you can use/dev/cdrom and/dev/fd0 to replace the mount point and get the same effect!

(4) mount? T msdos/dev/fd0/mnt/floppy: mount the DOS floppy disk to/mnt/floppy.

(5) mount Windows partitions

# Fdisk-l: List hard disk partitions.

# Mkdir/mnt/win: create a directory for mounting.

# Mount-t vfat/dev/hda1/mnt/win: Suppose Windows is in the first partition of the first IDE hard disk.

Note: can be used? T auto parameter makes the system automatically monitor the file type!

-R is mounted in read-only mode.

-W read/write mounting.

4.3 umount command uninstall the File System

(1) umount/mnt/floppy detach the device (such as/dev/fd0) from the mount point/mnt/floppy. You can also do this by using the following methods: umount/dev/fd0 to make the partition permanently available for Linux, you need to add the following line in the/etc/fstab file:

/Dev/hda1/mnt/win vfat defaults 0 0

V. File-related commands

5.1 File Permission chmod

Example:

Chmod 777 files-> rwxrwxrwx

Chmod 755 files-> rwx r-x

Chmod 644 files-> rw--r-

Chmod 000 files-> -〉---------

Chmod u + x g + w o + r file (give the file the right to be executable by the owner, writable by the same group, and read by others)
$ Chmod? R 777/tmp/test: Change the permissions of all files and directories in the directory (all permissions ).

$ Chmod? R 664/tmp/test: Disable the execution permission.

5.2 File Ownership

Chown user1 file (allocate file to user1)

5.3 mobile file mv

Example: mv abc def in this file abc moved its name to def.