clex software package provides command line file manager which uses the ncurses library, 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 clex
clex is installed in your system.
Make ensure the clex package were installed using the commands given below,
$ sudo dpkg-query -l | grep clex *
You will get with clex package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Miscellaneous |
| Package | clex |
| Version | 3.15-1.1 |
| Description | command line file manager which uses the ncurses library |
| Sub Section | Miscellaneous |