Shulou(Shulou.com)06/03 Report--

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Bash mathematical operations expr:

Syntax:

expr $num1 operator $num2

expr Available operators (operator):

#When comparing variables with expr command, return 1 if true, return 0 if false, different from shell command line, return 0 if true, return non-0 if false.

num1 |num2 #num1 is not empty and non-zero, returns num1, otherwise returns num2

num1 & num2 #num1 is not empty and not 0, return num1, otherwise return 0

num1

=num2, returns 1, otherwise returns 0

+, -, *, /, %, **

When expr is used in SHELL Syntax:

expr $num1 \| $ num2

expr $num1 \& $num2

expr $num1 \

$num2

expr $num1 \>= $num2

expr $num1 \ $num2

0

[root@test ~]#

[root@test ~]# expr $num1 + $num2

22

[root@test ~]#

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