1、变量声明不能有空格,不然会报变量找不到。
将空格去掉后
2、if else
name="ke"
# -z是判断长度的 if [ -z "${name}" ]; then echo "Jordon" else echo ${name} fi
if [ -z "${SPARK_HOME}" ];then echo ${SPARK_HOME} else echo "SPARK_HOME is:" ${SPARK_HOME} fi
3、输出执行命令
home=`cd $(dirname "$0");pwd` echo "current dir is :" ${home}