shell基础之99乘法表

方法一：

 1 #!/bin/bash
 2 for a in {1..9};do
 3         for b in {1..9};do
 4         c=`echo "$a*$b" |bc`
 5         if [ "$a" -ge "$b" ];then
 6         echo -n -e "$b*$a=$c\t"
 7         fi
 8         done
 9         echo
10 done

方法二：

1 #!/bin/bash
2 for a in `seq 1 9`;do
3         for b in `seq 1 $a`;do
4         c=`awk BEGIN"{print $a*$b}"`
5         echo -n -e "$b*$a=$c\t"
6         done
7         echo
8 done

方法三：

1 #!/bin/bash
2 for ((a=1;a<=9;a++));do
3         for ((b=1;b<=a;b++));do
4         echo -n -e "$b*$a=$((a*b))\t"
5         done
6         echo
7 done