Several methods of intercepting shell script string

1. Cut command

The cut command mainly accepts three positioning methods:

First, byte (bytes), with the option-b

Second, the character (characters), with the option-c

Third, fields (domain), with the option-f

Str= "abchyew2635" echo $str | cut-c 6-9

Results:

Yew2

2. # intercept, delete the left character and keep the right character

Var= "hello world" echo ${var#*l} result: lo world

Where var is the variable name, the # sign is the operator, and * l means to delete the first l and all characters on the left from the left.

That is, delete hel

3. Intercept with # #, delete the left character and retain the right character.

Var= "hello world" echo ${var##*l} result: d

# # * l means to delete the last (rightmost) l and all left characters from the left

That is, delete hello worl

4.% intercept, delete the right character and keep the left character

Var= "hello world" echo ${var%l*} result: hello wor

% l* means to start on the right and delete the first l and the characters on the right

That is, delete d

5.%% intercept, delete the right character and keep the left character

Var= "hello world" echo ${var%%l*} result: he

% l* means to start from the right, delete the last (leftmost) l and the right character

That is, delete llo world

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

Var= "hello world" echo ${var:0:3} result: hel

Where 0 indicates the beginning of the first character on the left, and 3 represents the total number of characters.

7. Start with the first character on the left and end it.

Var= "hello world" echo ${var:2} result: llo world

The 2 of them indicates that the third character on the left begins and ends.

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

Var= "hello world" echo ${var:0-2:3} result: ld

Where 0-2 indicates the start of the second character on the right, and 3 indicates the number of characters.

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

Var= "hello world" echo ${var:0-2} result: ld

Indicates that it starts with the second character on the right and ends.

General Code:

#! / bin/bashvar= "hello world" echo ${var#*l} echo ${var##*l} echo ${var%l*} echo ${var%%l*} echo ${var:0:3} echo ${var:2} echo ${var:0-2:3} echo ${var:0-2} [fbl@www test6_16] $. / string.sh lo worlddhello worhehelllo worldldld