Linux expr command
Translation results：
expr
[Calculation][WIN]Expression
Linux expr commandsyntax
Function: The expr command is a manual command line counter, used to find the value of expression variables under UNIX/LINUX. It is generally used for integer values, but can also be used for strings.
Syntax: expr expression
Linux expr commandexample
1. Calculate the length of the string
> expr length “this is a test” 14
2. Fetch the string
> expr substr “this is a test” 3 5 is is
3. Fetch the first occurrence of the character string Position
> expr index "sarasara" a 2
4, Integer operation
> expr 14 % 9 5 > expr 10 + 10 20 > expr 1000 + 900 1900 > expr 30 / 3 / 2 5 > expr 30 \* 3 (使用乘号时，必须用反斜线屏蔽其特定含义。因为shell可能会误解显示星号的意义) 90 > expr 30 * 3 expr: Syntax error