if fi shell 脚本

weiqifa@ubuntu:~/logcat$ source test.sh 
please input the packageName
weiqifa@ubuntu:~/logcat$ source test.sh aa
input ok
weiqifa@ubuntu:~/logcat$ cat test.sh 
#!/bin/bash
if [ -z "$1" ];then
echo "please input the packageName"
else
echo "input ok"
fi
weiqifa@ubuntu:~/logcat$ 

1、开头还是要有#!/bin/bash

2、if 和[之间要有一个空格，否则会提示 {syntax error near unexpected token `then'}

3、[ -z "$1" ]  $1是输入的第一个参数，-z跟左边的[也要有空格，不然判断结果都是跑else了。