总结

Don‘t use a piping operator, which is what ">" Redirection is.

不要使用管道运算符，即“>”。

All programs have three streams:

• Standard Input (the input from the console)
• Standard Output (general logging/UI output to the console)
• Standard Error (logging/UI output to the console meant for error messages or other exceptional behavior)

command >nul

^ This says to pipe the standard-output stream to null.

command 2>nul

^ This says to pipe the standard-error stream to null.

command 2>&1

^ This says to pipe the standard-error stream to the same place as the standard-output stream.

1>nul 2>nul

uses 1 for Standard Output and 2 for Standard Error.

1>nul 意思是不显示命令运行的正确提示
2>nul 是不显示错误提示

如果放在一起就是， 正确提示&错误提示将都不显示

>是重定向符号

nul是空设备的意思

把提示输入到空设备就不显示了 

Batch - 重定向符号 >

原文：https://www.cnblogs.com/frankcui/p/11630307.html