What is the command to check a port?检测端口的命令是什么？

[Firfr]

For some reasons, I need to identify if a device is online by checking the status of a specified port instead of using the default ping method. The software has the functionality to check ports. So, can the default ping command be replaced with a command to check a specified port? If so, what is the command?

因为一些原因，我需要通过判断设备指定的端口状态来识别是否在线，而不是默认的ping，软件有检测端口的功能，那么能否把默认得到ping命令替换成检测指定端口的命令？如果可以，请问命令是什么？

[seriousm4x]

You could use the following ping command:

nc -z -w 1 <ip> <port>; exit $?

Replace the ip and port. The command will exit 0 if port is open and exit 1 if closed. -w 1 sets a timeout of 1 second.

[Firfr]

非常感谢您得到回答，帮了大忙
Thank you very much for your answer. It was a great help!