Finding about which OS is running via shell script

[Paul Smith]

On Fri, 2013-04-26 at 22:46 +0300, Kevin Wilson wrote:
> My aim is to right a script that will behave differently
> when running it on Fedora or running it on Ubuntu.
> Is there a way to know from Bash whether the OS is ubuntu or
> Fedora (besides parsing /etc/issue ) ?

All LSB-compliant distributions will support the lsb_release command.
See the man page.

  $ lsb_release -a
  LSB Version:    :core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
  Distributor ID: CentOS
  Description:    CentOS release 6.3 (Final)
  Release:        6.3
  Codename:       Final

  $ lsb_release -s -i
  CentOS

  $ lsb_release -s -r
  6.3