创建新文件：touch test.sh
添加可执行权限：chmod +x test.sh
编辑文件：gedit test.sh
输出命令：echo "hello world"
正常退出：exit 0
给命令起别名：alias hello="echo ‘hello world‘"
撤销别名：unalias hello
取命令执行结果：echo "the current directory is $(pwd)" | echo "the current directory is `pwd`"
原文：https://www.cnblogs.com/abuduri/p/12814183.html