Linux shell 基础语法 逻辑条件判断 if

1.Linux if 条件判断 是单等于号，str1 = str2　当两个串有相同内容、长度时为真

2.If 的好前后要用空格

3.方括号前后要有空格 if [ $1 = 'a' ]

4.condition [] 后要接分号;

4.条件判断与逻辑 需要两个方括号包含 条件逻辑

5.if elif，而不是if else if

if [[ $1 = 'tomcat' ]];
then
  echo "Input is tomcat"
elif [[ $1 = 'redis' ]] || [[ $1 = 'zookeeper' ]];
then
  echo "Input is $1"
else
  echo "Input Is Error."
fi

if [ $2 = 'true' ]; then
	echo "fake data true"
fi

if [ condition ];then

...statement..

elif [ condition ];then

...statement..

fi