Suppose there is variable var=http://www.aaa.com/123.htm.
1. Intercept the # sign, delete the characters on the left, and keep the characters on the right.
|
1
|
echo ${var#*
//}
|
Where var is the variable name, the # sign is the operator, *// means to delete the first // sign and all the characters on the left from the left,
that is, delete http://
and the result is: www.aaa.com/123.htm
2. The ## sign is intercepted, the characters on the left are deleted, and the characters on the right are reserved.
|
1
|
echo ${var##*/}
|
##*/ means to delete the last (rightmost) / sign from the left and all the characters on the left to
delete http://www.aaa.com/
The result is 123.htm
3. % sign interception, delete the right character, keep the left character
|
1
|
echo ${var%/*}
|
%/* means start from the right, delete the first / sign and the characters to the right
The result is: http://www.aaa.com
4. %% sign interception, delete the characters on the right, keep the characters on the left
|
1
|
echo ${var%%/*}
|
%%/* means start from the right, delete the last (leftmost) / sign and the characters on the right. The
result is: http:
5. The first character from the left, and the number of characters
|
1
|
echo ${var:
0
:
5
}
|
Where 0 indicates the start of the first character on the left, and 5 indicates the total number of characters.
The result is: http:
6. Start with the first few characters from the left and continue to the end.
|
1
|
echo ${var:
7
}
|
The 7 represents the beginning of the 8th character from the left and continues until the end.
The result is: www.aaa.com/123.htm
7. The first few characters from the right, and the number of characters
|
1
|
echo ${var:
0
-
7
:
3
}
|
Among them, 0-7 means the seventh character from the right, and 3 means the number of characters.
The result is: 123
8. Start with the first few characters from the right and continue until the end.
|
1
|
echo ${var:
0
-
7
}
|
Indicates from the seventh character from the right to the end.
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)