nmcli 是 NetworkManager 的控制客户端，通过 man 查看可知：
NMCLI(1) General Commands Manual NMCLI(1)
NAME
nmcli - command-line tool for controlling NetworkManager
SYNOPSIS
nmcli [OPTIONS...] {help | general | networking | radio | connection | device | agent | monitor} [COMMAND] [ARGUMENTS...]
DESCRIPTION
nmcli is a command-line tool for controlling NetworkManager and reporting network status. It can be utilized as a replacement for nm-applet or other
graphical clients. nmcli is used to create, display, edit, delete, activate, and deactivate network connections, as well as control and display network
device status.
Typical uses include:
· Scripts: Utilize NetworkManager via nmcli instead of managing network connections manually. nmcli supports a terse output format which is better
suited for script processing. Note that NetworkManager can also execute scripts, called "dispatcher scripts", in response to network events. See
NetworkManager(8) for details about these dispatcher scripts.
· Servers, headless machines, and terminals: nmcli can be used to control NetworkManager without a GUI, including creating, editing, starting and
stopping network connections and viewing network status.
man 手册中 有两个关于nmcli 的使用条目，使用 man -k 命令即可以查看：
nmcli (1) - command-line tool for controlling NetworkManager
nmcli-examples (7) - usage examples of nmcli
使用 man nmcli-examples 命令，可以查看 nmcli 的最新的用法。
详细的使用，可以参考如下链接，我就不做重复工作了:
man nmcli-examples
https://access.redhat.com/documentation/zh-cn/red_hat_enterprise_linux/7/html/networking_guide/sec-using_the_networkmanager_command_line_tool_nmcli
https://nullr0ute.com/2016/09/connect-to-a-wireless-network-using-command-line-nmcli/
https://www.cnblogs.com/MiKaDoNik/p/8064313.html
以下链接，你将更好得了解 networkmanager :
https://access.redhat.com/documentation/zh-cn/red_hat_enterprise_linux/7/html/networking_guide/sec-introduction_to_networkmanager
[NetworkManager 提供的默认联网服务是一个动态网络控制和配置守护进程，它尝试在其可用时保持网络设备和连接处于活动状态。]
保持更新，转载请注明出处。