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Today, the editor will share with you the relevant knowledge points about how to intercept Linux strings. The content is detailed and the logic is clear. I believe most people still know too much about this, so share this article for your reference. I hope you can get something after reading this article. Let's take a look at it.

Suppose there is a variable var= http://www.aaa.com/123.htm

The number is intercepted, the left character is deleted and the right character is retained. Echo ${var#//} where var is the variable name, the # sign is the operator, and / / means the first / / sign and all characters on the left are deleted from the left.

That is, delete http://

The result is: www.aaa.com/123.htm

Intercept, delete the left character, retain the right character echo ${var##/} # # / means to delete the last (rightmost) / sign and all left characters from the left

That is, delete http://www.aaa.com/

The result is 123.htm.

% intercept, delete the right character, keep the left character

Echo ${var%/}% / means to start on the right and delete the first / sign and the characters on the right

The result is: http://www.aaa.com

%% intercept, delete the right character, keep the left character

Echo ${var%%/}% / means to start on the right and delete the last (leftmost) / sign and the right character

The result is: http:

Start with the number of characters on the left and the number of characters

The 0 in echo ${var:0:5} indicates the beginning of the first character on the left, and 5 represents the total number of characters.

The result is: http:

Start with the first character on the left and go to the end.

The 7 of echo ${var:7} indicates the start of the eighth character on the left and the end.

The result is: www.aaa.com/123.htm

Start with the number of characters on the right and the number of characters

The 0-7 of echo ${var:0-7:3} indicates the beginning of the seventh character on the right, and 3 indicates the number of characters.

The result is: 123

Start with the first character on the right and go to the end.

Echo ${var:0-7} indicates that it starts with the seventh character on the right and ends.

The result is: 123.htm

Note: (the first character on the left is represented by 0, and the first character on the right is represented by 0-1.

These are all the contents of the article "how to intercept Linux strings". Thank you for reading! I believe you will gain a lot after reading this article. The editor will update different knowledge for you every day. If you want to learn more knowledge, please pay attention to the industry information channel.

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