使用if/then结构的条件测试可以嵌套。最终结果等同于使用 && 复合比较运算符。
a=3
if [ "$a" -gt 0 ]
then
if [ "$a" -lt 5 ]
then
echo "The value of \"a\" lies somewhere between 0 and 5."
fi
fi
# Same result as:
if [ "$a" -gt 0 ] && [ "$a" -lt 5 ]
then
echo "The value of \"a\" lies somewhere between 0 and 5."
fi |