如下脚本
#!/bin/bash def1=1 for i in def1 def2; do if [ "${!i}" = "" ]; then echo "not define" $i else echo "define" $i ${!i} fi done
执行结果为
define def1 1 not define def2
shell编程笔记
原文：https://www.cnblogs.com/armme/p/9891203.html
