file software package provides Recognize the type of data in a file using magic numbers, 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 file
file is installed in your system.
Make ensure the file package were installed using the commands given below,
$ sudo dpkg-query -l | grep file *
You will get with file package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Utilities |
| Package | file |
| Version | 1:5.29-1 |
| Description | Recognize the type of data in a file using magic numbers |
| Sub Section | Utils |