Bash中判断一个命令的输出结果是否为空

如果我们想在Bash中判断一个命令的输出结果是否为空，我们可以使用test命令和-z参数。示例代码如下：

if test -z "$(ls | grep test1.txt)"; then
    echo "The result is empty."
else
    echo "The result is not empty."
fi
 
if test ! -z "$(ls | grep test2.txt)"; then
    echo "The result is not empty."
else
    echo "The result is empty."
fi