[Boiled water]-shell-from numerical N to M (n<m)-Knowledge point

Title: Numerical N accumulates to M (n<m)

In the following example, the examples are 1 to 100, and they can be brought into N and M (n<m) entirely by themselves.

For loop implementation

Sum=0for ((i=1;i<=100;i++)) do sum=$ ((i+ $sum)) Doneecho $sum

By using variable arithmetic to implement

Echo $[$ (Echo +{1..100})]echo $ (($ (Echo +{1..100})) echo $[(100+1) * (100/2)]

Knowledge Points:

I=2&&echo $ ((i+3)) # Prints new variable results after calculation I=2&&echo $[i+3]# calculation of new variable results

$ (()) and $[] As a result, the two variables are expressed in different forms, but the results are the same

Implemented with SEQ and BC commands

Seq-s ' + ' |BC

Knowledge Points:

Seq Common parameter # does not specify the starting value, the default is 1-s # option mainly change the output of the splitter, the preset is \n-w # equal complement, that is, the width equals, insufficient front fill 0-f # formatted output, is the format of the specified printing

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[Boiled water]-shell-from numerical N to M (n<m)-Knowledge point