shell脚本打印平行四边形、菱形

#!/bin/bash

for ((i=1;i<=9;i++))
do
     for ((j=9;j>=i;j--))
     do
           echo -n " "
     done

     for ((j=2;j<=i;j++))
     do
           echo -n "*"
     done
     for ((j=1;j<=i;j++))
     do
           echo -n "*"
     done
     for ((j=9;j>=i;j--))
     do
           echo -n "*"
     done
     for ((j=9;j>=i;j--))
     do
           echo -n "*"
     done
     echo 
done

#! /bin/bash
for ((i=1;i<=9;i++))
do
     for ((j=9;j>=i;j--))
     do
           echo -n " "
     done

     for ((j=2;j<=i;j++))
     do
           echo -n "*"
     done
     for ((j=1;j<=i;j++))
     do
           echo -n "*"
     done
     echo
done

for ((i=1;i<=9;i++))
do
     for ((j=1;j<=i;j++))
     do
           echo -n " "
     done
     for ((j=8;j>=i;j--))
     do
           echo -n "*"
     done
     for ((j=9;j>=i;j--))
     do
           echo -n "*"
     done
     echo 
done