String interception of Linux is useful. There are eight ways.
Suppose there is a variable var=http://www.hao.com/123.htm
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A # Intercept, delete the left character, and leave the right character.
Echo ${var#*//}
where Var is the variable name and the # is an operator,*// indicates that the first//number and all characters on the left are deleted from the left.
Delete http ://
The result is:www.hao.com/123.htm
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Two # # Intercept, delete the left character, leave the right character.
Echo ${var##*/}
##*/ indicates that the last (rightmost) one/number and all characters to the left are deleted from the left.
That is, delete http://www.hao.com/
The result is 123.htm.
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Triple 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.hao.com
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Four-percent 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:
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Start with 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:
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Six starts with 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.hao.com/123.htm
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Seven starts 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: 123
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Eight starts from the first character 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.
Result is: 123.htm
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Note: (The first character on the left is denoted by 0, and the first character on the right is denoted by 0-1)
Several ways to intercept strings in Linux