Using the shell for mathematical operations

You can use, let (()) [] perform basic arithmetic operations, and use advanced operations bc more efficiently.

Look directly at the code and the output is clear.

Let

[Zhengweiwu A: -~]$ no1=4[Zhengweiwu A: -~]$ no2=5[Zhengweiwu A: -~]$ Letresult=no1+no2[zhengweiwu A: -~]$ echo $result9[Zhengweiwu A: -~]$ Letresult=result+0.9 # Operators cannot have spaces on either side-bash:let: +: SyntaxError: Operand expected (ErrorToken is "+") [Zhengweiwu A: -~]$ Letresult=result+0.9 # Only integer operations can be performed-bash:let:result=result+0.9: syntaxError: Invalid arithmetic operator (ErrorToken is ". 9") [Zhengweiwu A: -~]$ echo $result9

[]

[zhengweiwu 22  :  26  ~]$  Result=$[ no1+no2][zhengweiwu 22  :  27  ~]$  echo $ Result  9  [Zhengweiwu 22  :  27  ~]$  result=$[  no1+no2+1 ][zhengweiwu 22  :  27  ~]$  echo  $result  10   

(())

[Zhengweiwu A: -~]$ result=$((1+1)) [Zhengweiwu A: -~]$ Echo$result2[Zhengweiwu A: -~]$ result=$((Ten+1)) [Zhengweiwu A: in~]$ Echo$result One

Bc

[zhengweiwu 22 : 29  ~]$ echo  " 4*3.5 " | Bc14.0  [Zhengweiwu 22 : 29  ~]$ echo   "4*3.54 " | Bc14.16  [Zhengweiwu 22 : 30  ~]$ result=$ (echo   " $no 1  *0.44"  | BC) # as a child shell calculation result  [Zhengweiwu 22 : 30  ~]$ echo   $result  Span class= "Hljs-number" >1.76   

[zhengweiwu 22 : 30  ~]$ echo  " SCALE=2;3/8 " | BC # set decimal precision . 37  [Zhengweiwu 22 : 31  ~]$ echo   "SCALE=4;3/8"  | Bc. 3750  [Zhengweiwu 22 : 31  ~]$ echo   "SCALE=6;3/8"  | Bc. 375000   

[zhengweiwu 22 : 31  ~]$ no=100  [Zhengweiwu 22  : 33  ~]$ echo   "Obase = 2;  $no  " | BC # output is 2 binary, the default input is 10 binary  1100100  [Zhengweiwu Span class= "Hljs-number" >22 : 33  ~]$ no=1100100  [Zhengweiwu 22 : 33  ~]$ echo   $no   | BC # indicates output and input  100   

22:34echo"sqrt(100)" | bc1022:35echo"10^10" | bc10000000000

Using the shell for mathematical operations