Stopping Android Emulator From Command Line

To stop all Android emulator instance, we do,

adb emu kill

If we want to kill a specific Android emulator instance, we need to find out the device's serial number or identifier. For this, we do,

adb devices

The typical emulator serial number or identifier is emulator-5554. Using this as an example, we can kill the emulator instance using the command below,

adb -s emulator-5554 emu kill

Reinstalling disappeared ddclient

I upgraded a CentOS 8 host to CentOS Stream 8. Later I discovered the ddclient package disappeared. I attempted to install it, and this error occurred. 

$ sudo dnf install ddclient
 Problem: conflicting requests
  - nothing provides perl(Digest::SHA1) needed by ddclient-3.9.1-1.el8.noarch
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)
$

A research on the web tells me that I need the PowerTools package. To find out the exact name of the package, 

$ dnf repolist all | grep -i tool
powertools                               CentOS Stream 8 - PowerTools   enabled
powertools-source                        CentOS Stream 8 - PowerTools - disabled
$

Following this, I enable the repo

$ sudo dnf install ddclient
CentOS Stream 8 - PowerTools                    2.5 MB/s | 4.2 MB     00:01
......
......
Complete!
$