Bonjour
michel@debg53sw:~$ lsb_release -a
No LSB modules are available.
Distributor ID:	Debian
Description:	Debian GNU/Linux 8.8 (jessie)
Release:	8.8
Codename:	jessie
michel@debg53sw:~$ grep '^ID=' '/etc/os-release' | cut --delimiter='=' --fields=2
debian
michel@debg53sw:~$ head --lines=1 '/etc/issue' | cut --delimiter=' ' --fields=1 | tr [:upper:] [:lower:]
debian
michel@debg53sw:~$ lsb_release --id --short | tr [:upper:] [:lower:]
debian
michel@debg53sw:~$ 
michel@debstretch:~$ lsb_release -a
No LSB modules are available.
Distributor ID:	Debian
Description:	Debian GNU/Linux 9.0 (stretch)
Release:	9.0
Codename:	stretch
michel@debstretch:~$ grep '^ID=' '/etc/os-release' | cut --delimiter='=' --fields=2
debian
michel@debstretch:~$ head --lines=1 '/etc/issue' | cut --delimiter=' ' --fields=1 | tr [:upper:] [:lower:]
debian
michel@debstretch:~$ lsb_release --id --short | tr [:upper:] [:lower:]
debian
michel@debstretch:~$ 
michel@virtubu:~$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 16.04.2 LTS
Release:	16.04
Codename:	xenial
michel@virtubu:~$ grep '^ID=' '/etc/os-release' | cut --delimiter='=' --fields=2
ubuntu
michel@virtubu:~$ head --lines=1 '/etc/issue' | cut --delimiter=' ' --fields=1 | tr [:upper:] [:lower:]
ubuntu
michel@virtubu:~$ lsb_release --id --short | tr [:upper:] [:lower:]
ubuntu
michel@virtubu:~$ 
      
    
