What is the function of the vyysh command in Linux? See it often!

This is what Windows Terminal can see.

For Tomcat in Linux, you can see this information in the logs directory where Tomcat is located, and the startup information is written to the log file. This is usually the file tomcat logs

ya178 gang gang:

With the command ps -aux |grep tomcat to see if there is a tomcat process, if so, it is started. You can also view the output logs, but they are generally large and are not recommended.

1. For a server, a very important aspect is its "availability", that is, the selected server can meet the requirements of long-term stable work and cannot often have problems. In fact, it is equivalent to the reliability proposed by Sun.

2. Because the server is facing the users of the entire network, rather than a single user, in large and medium-sized enterprises, the server is usually required to be uninterrupted.

3. In some special application fields, even if there is no user use, some servers have to work uninterruptedly, because it must continue to provide users with connection services, whether it is at work, or off work, whether it is a working day, or a break, or a holiday.

4. This is the fundamental reason why the server must have extremely high stability.

You can see this information when tomcat starts, right?

The touch command has two functions: one is to update the time tag of an existing file to the current time of the system.

There are 2 main uses:

Create a blank new file.

Update the timestamp of an existing file.

The usage is the same, touch filename.

1. Check the catalog.

The content of the next file is used to view the file directory in the current directory. cat means to view the contents of the file) The discovery content is hello world

2. Use vi to enter the interface, as follows:

3. Enter the mode, press the button I, at this time you can move the cursor to the position you want to modify, and we modify the content as follows: (Note that the lower left corner of the interface has entered the insert mode, which means that it is now the mode).

4. Push out the mode, and save, press the esc key to exit the insert mode, and then press shift+: shift+colon key), and then enter wq, wq means, save and exit. If you only press the Q button, it will only exit and not save.

5. Finally, press Enter to exit the interface, check the content again, and verify it, as shown in the figure below.

First open your command-line tool, if it's Windows, then switch to the directory where you modified the file, and then do the following:

Step 1: Check the contents of the files in the directory and use cat

ls indicates that the file directory under the current directory is viewed; cat indicates to view the contents of the file).

The discovery content is hello world

Step 2: Use vi to enter the interface, as shown below:

Step 3: Enter the mode, press the button I, at this time you can move the cursor to the position you want to modify, and we modify the content as follows: (Note that the lower left corner of the interface enters the insert mode, which means that it is now the mode).

Step 4: Eject the mode, and save, press the esc key to exit the insert mode, then press shift+: shift+colon), then enter wq, wq means, save and exit.

If you only press the Q button, it will only exit and not save.

Finally, press Enter to exit the interface, review the content again, and verify:

Supplement upstairs, after modifying press esc to enter control mode, and then: w save. :wq is the ...... to save and exit

Press i to enter insert mode, after changing it.

w Save.

yy is a copy. The preceding number is the number of lines copied. 5yy, that is, copy 5 lines, the line where the cursor is located, and the following 4 lines.

Paste with p

If you don't have a graphical interface, use the command in vi to copy, the command is as follows:

yy copies the current row.

yw to copy a word.

y$ to copy the cursor to the end.

y Copy the cursor to the beginning of the line.

yy copy line.

yw copy the word.

m, ny copy m to n line content.

When you have a graphical interface, you can also use the right-click to copy and paste.

Select the text you want to copy, then right-click Copy. Paste to the place where you need to paste

If you only copy one line, you can press yy on the line you want to copy, and then press p on the line you want to paste.

If you want to copy multiple lines, such as 3 lines, you can press 3yy, and then press p.

Click the Esc key.

Move the cursor to the line you want to copy.

Enter yy (if you copy n lines, enter nyy) and move the cursor to the line you want to paste. Enter p

yw : Copies the characters from where the cursor is located to the end of the word into the buffer.

yw: Copy words to the buffer.

yy: Copy the cursor's line to the buffer.

yy: For example, 6yy means that the copy is "counted down" 6 lines of text from the line where the cursor is located.

p: Paste the characters in the buffer to the cursor. Note: All copy commands related to "y" must be paired with "p" in order to complete the copy and paste function.

1. First of all, there is a directory dir, run ln -s dir dir link to create a soft link to the directory.

2. Recreate the MKDIR source directory, and the soft link to the directory will take effect again.

3. Run the ln dir dir hard command to create a hard link to the directory.

4. Run the ln -s file file link command to create a soft link for the file file.

5. Run the ln file file hard command to create a hard link to the file file hard.

6. Modify the hard link file hard, cat file, and update to the source file at the same time.

yy means to copy the entire row. 5yy means copying five elements.

vim has a similar command. For example, d means delete, followed by a range. dd is to delete the entire line.

The whole line operation is very common, so these shortcuts are added. Without a command like this, copying and deleting entire lines would be troublesome. You need to move the cursor to the beginning of the line first, and then use y$ to copy it.

Copy 5 lines to the buffer, these 5 lines contain the line where the cursor is located and the 4 lines below the cursor, use"p"Pasting can be implemented.

date "+%y-%m-%d %h-%m-%s "

This is the time format after the display time + is displayed.

d is a specified point in time or time period to be displayed, and you write a whole bunch of time formats after -d and it certainly doesn't recognize it.