conky-cli software package provides highly configurable system monitor (basic version), you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install conky-cli
conky-cli is installed in your system.
Make ensure the conky-cli package were installed using the commands given below,
$ sudo dpkg-query -l | grep conky-cli *
You will get with conky-cli package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Utilities |
| Package | conky-cli |
| Version | 1.10.5-1 |
| Description | highly configurable system monitor (basic version) |
| Sub Section | Utils |