1.判断输入是否是数字,并且输出简单图形
#!/bin/bash read -p "input a num: " num #判断输入是否是数字,直到输入正确数字为止 flag=true while $flag do if [ -n "$num" ];then test=$(echo "$num"|sed 's/[0-9]//g') if [ -z "$test" ];then flag=false fi fi [ "$flag" == "false" ] || read -p "input correct num: " num done for (( i=1;i<=$num;i++ )) do for j in $(seq 1 $i) do echo -n "*" done echo done echo "############" for (( i=$num;i>=1;i-- )) do for j in $(seq 1 $i) do echo -n "*" done echo done
2.测试结果: