The shell command under Linux

First, the basic command
1. Immediately shutdown and restart, execute the following command: Shutdown-r now or reboot
2. Immediately shutdown, execute the following command: Shutdown-h now or Poweroff
3, wait 2 minutes shutdown and restart, execute the following command: Shutdown-r 2
4, wait 2 minutes shutdown, execute the following command: Shutdown-h 2
5, using the current user's history command, do the following:
The history will display each command and its ordinal number used, and the command can be executed repeatedly with an ordinal. For example, enter! 1 and enter, the 1th Historical command will be executed repeatedly. You can also use the UP and down cursor keys to bring up a history command, and then press ENTER to repeat. You can also use the UP and down cursor keys to bring up a history command, modify and press ENTER to execute.
6, clear the current user's history command, execute the following command: History-c this time with the UP cursor key will not make any history command.
7, command Prompt key <tab>: Enter the command at the beginning of one or several letters, and then press 1 times "tab" key, the system will automatically fill the recognized parts, and then press 1 "tab" key, the system displays all the commands that match the criteria for the user to select. For example, after entering group two times <Tab> key, all commands starting with group will be displayed
8, display the kernel version number, execute the following command: Uname-r Note: The kernel version number differs from the software release version number. For example, the kernel version number for RHEL 5.4 is 2.6.18-164.EL5 and the software release version number is 5.4.
9. Clear the screen and execute the following command: Clear
10. Display the operating system clock, execute the following command: Date
11, load the CD to/media, execute the following command: Mount/dev/cdrom/media
12. Unmount the disc and execute the following command: Umount/dev/cdrom or Umount/media Note: Do not execute this command in/media or its subdirectories, or a "device busy error" will occur.
13, check the storage device, execute the following command: Fdisk–l
14. Load USB drive to/mediamount/dev/sdb1/media
15, uninstall the USB flash drive, execute the following command: UMOUNT/DEV/SDB1 or Umount/media Note: Do not execute this command in/media or its subdirectories, or you will see a "Device busy error". 16 Interrupt Shell command CTRL + C
Second, the file directory Operation command
1. Display the current absolute path, execute the following command: PWD
2, change the current directory, for example, execute the following command: Cd/etc/yum will change the current directory to/etc/yum.
3. Go back to the parent directory of the current directory and execute the following command: CD.
4, create the directory, for example, execute the following command: Mkdir/usr/tigger
5, delete the directory, for example, execute the following command: Rmdir/usr/tigger Note: When using the RmDir command, the directory to be deleted must be empty.
6, List the contents of the directory, for example, execute the following command: LS/
7. List all content in the directory (including hidden files or point files), for example, execute the following command: Ls/root-a will see "." The file names that begin with, which are called point files. If the command "Ls/root" is not visible to them.
8, in a long format to list the contents of the directory, execute the following command: ls/boot-l Note: In Linux, if a command has several switches, you can merge these switches together. For example, the command ls-a-L has the same effect as the command ls-al or Ls-la.
9. Create an empty file, for example, execute the following command: Touch/a.dat
10, copy the file, for example, execute the following command: Cp/etc/host.conf/root will copy the files in the directory/etc host.conf to the directory/root, the file name is not changed.
11, copy the entire subdirectory (do not change the directory name), for example, execute the following command: Cp-r/usr/include/root will copy the entire subdirectory/usr/include (without changing the directory name) to the directory/root. 12, copy the entire subdirectory (change directory name), for example, execute the following command: Cp-r/usr/include/root/include2 will copy the entire subdirectory/usr/include to the directory/root, and change the directory name from include to Include2.
13, move the file or rename the file, for example, execute the following command: Rename the file: Mv/root/host.conf/root/myfile Move File: Mv/root/myfile/Move file name change: mv/myfile/root/myfile2
14, delete the file, for example, execute the following command: Rm/root/myfile2 Press y key to confirm. Rm-f/a.dat no need to confirm.
15, delete the non-empty directory, for example, execute the following command: Mkdir/root/mysub/root/mysub/new rmdir/root/mysub system prompts the directory non-empty rm-rf/root/mysub system without error prompts. Ls/root will see no mysub directory in directory/root
16, split screen display file content, such as the following command: More/etc/services press the SPACEBAR to display the next screen, press the Q key to return to the command line status. Note: More as a pipe command, can be combined with some other commands, for example: ls/etc |more history |more
17, display the contents of the file, for example, execute the following command: cat/etc/services
18, merge files, for example, execute the following command: Cat/etc/resolv.conf/etc/yum.conf >/b.dat performs the following command to verify: Ls-l/b.dat shows that the file length is 814 bytes. The same functionality can also be achieved with two commands: cat/etc/resolv.conf >/c.dat The file length is 26 bytes at this time. cat/etc/yum.conf >>/c.dat The file is now 814 bytes long. Note:> and >> are redirect symbols, and if the redirected file already exists, using > will overwrite the original content with the new content, while using >> will add the new content to the back of the original content.

VI Editor Create or modify a text file, for example, execute the following command: The Vi/b.dat VI editor has 2 modes: Command mode and edit mode.
VI after the launch of the command mode, in the command mode by pressing the I key to enter the editing mode.
Press the <Esc> key in edit mode to return to the command mode.
Press the I key to start editing.
After editing, press the <Esc> key to return to the command mode, enter: Wq after pressing ENTER to save the file after the exit, or enter: q! after press ENTER does not disk to exit.
To delete the line where the cursor is located, return to command mode and press the D key two times.
To delete several rows that start at the beginning of the line where the cursor is located, such as 5 rows, return to command mode, press 5, and then press the D key two times. Delete Content at the same time into VI

The shell command under Linux