Shell program to display multiplication tables

Introduction

I created it as a small story of Bash programming. This is the 4th bullet.

Display the multiplication table

Source

#!/bin/bash

ans=0
spc=' '

for i in $(seq 1 9)
do
  for j in $(seq 1 9)
  do
    ((  ans = $i * $j ))
    printf "%2d" $ans
    echo -e "${spc}\c"
    if (( $j == 9 ))
      then
      echo #Line break
    fi
  done
done

I used printf to force it to be 2 digits even if it is 1 digit. Since it is difficult to see if the numbers are continuous, I put a space between each value.

Execution result

$ ./kuku.sh
 1  2  3  4  5  6  7  8  9
 2  4  6  8 10 12 14 16 18
 3  6  9 12 15 18 21 24 27
 4  8 12 16 20 24 28 32 36
 5 10 15 20 25 30 35 40 45
 6 12 18 24 30 36 42 48 54
 7 14 21 28 35 42 49 56 63
 8 16 24 32 40 48 56 64 72
 9 18 27 36 45 54 63 72 81

in conclusion

By creating this program

--Repeating syntax --printf command -Calculation using (()) --Bash's manners

I understand.