shell to for

#!/bin/bash
#echo -n "*" 不回車
#seq 9 生成1到9
for i in {1..5}
do

for j in $(seq $[5-i])
    do
          echo -n " "
    done

    for k in $(seq $[2*i-1])
    do
        echo -n "*"
    done

    echo

done

    *
   ***
  *****
 *******
*********

憂化

#!/bin/bash
x=0
for i in {1..10}
do
if [ $i -gt 5 ];then
x=$[x+2]
i=$[i-x]
fi

for j in $(seq $[5-i])
do
    echo -n " "
done

for k in $(seq $[2*i-1])
do
    echo -n "*"
done
echo

done

    *
   ***
  *****
 *******
*********
 *******
  *****
   ***
    *