Interception of strings in the shell

9 Kinds of interception of strings in shell, take var=http://www.google.com/test/.html as an example

(1) Method one: # Intercept, delete the left character, retain the right character.

Echo ${var#*//}

var is the variable name, and the # is the operator, *//means to delete the first//number and all characters from the left, starting from the left.

(*: Match 0 or more of any characters)

Delete http://

The result is: www.google.com/test.html

(2) method two: # # Intercept, delete the left character, retain the right character.

Echo ${var##*/}

##*/indicates that the last (rightmost) one/number and all characters on the left are deleted from the left.

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

The result is test.html.

(3) method three:% intercept, delete the right character, leave the left character

Echo ${var%/*}

%/* indicates that the first/second and right characters are deleted from the right.

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

(4) method Four: The percent number intercept, delete the right character, leave the left character

Echo ${var%%/*}

%%/* indicates that the last (leftmost) one/number and right character are deleted from the right.

The result is: http:

(5) method five: Starting from the first few characters on the left, and the number of characters

Echo ${var:0:5}

0 represents the first character on the left and 5 indicates the total number of characters.

The result is: http:

(6) method six: Starting from the first few characters on the left, until the end.

Echo ${var:7}

7 means that the 8th character on the left begins, until the end.

The result is: www.google.com/test.html

(7) method Seven: Start with the first character on the right and the number of characters

Echo ${var:0-7:3}

0-7 means that the seventh character starts at the right, and 3 indicates the number of characters.

The result is: test

(8) method eight: Starting from the first few characters on the right, until the end.

Echo ${var:0-7}

The expression starts at the seventh character on the right and continues to the end.

The result is: test.html

(9) Method IX: Split according to the specified requirements.

For example, get the suffix name

Ls-al | Cut-d "."-f2

The Cut command can split a line of characters by a specified delimiter,-d specifies the delimiter,-f specifies which character to output

such as: echo "a/b/c" |cut-d '/'-F 1.

The result of the execution is a.

Execution process: First press/segment, the result is: The first field is a, the 2nd field is B, and the 3rd field is C,-f is the number of fields.

Note: (The first character on the left is denoted by 0, and the first character on the right is denoted by 0-1)

Related commands

1. : command: Intercept by number.

2. # command: Get the right character, starting with the first one from the left.

3. # # command: Gets the right character, starting with the last one from the left. (% similar)

4. % command: Gets the left character starting from the right with the first

5. Percent command: Gets the left character starting from the right with the last

This article is from the "sunshine225" blog, make sure to keep this source http://10707460.blog.51cto.com/10697460/1790442

Interception of strings in the shell