$ firejail firefox            # starting Mozilla Firefox
$ firejail transmission-gtk   # starting Transmission BitTorrent
$ firejail vlc                # starting VideoLAN Client
$ sudo firejail /etc/init.d/nginx start

      --private-opt=file,directory
              Build  a  new /opt in a temporary filesystem, and copy the files
              and directories in the list.  If no listed file is  found,  /opt
              directory  will  be empty.  All modifications are discarded when
              the sandbox is closed.

              Example:
              $ firejail --private-opt=firefox /opt/firefox/firefox

       --private-srv=file,directory
              Build a new /srv in a temporary filesystem, and copy  the  files
              and  directories  in the list.  If no listed file is found, /srv
              directory will be empty.  All modifications are  discarded  when
              the sandbox is closed.

              Example:
              # firejail --private-srv=www /etc/init.d/apache2 start

      --machine-id
              Spoof id number in /etc/machine-id file - a  new  random  id  is
              generated inside the sandbox.

              Example:
              $ firejail --machine-id

       --allow-private-blacklist
              Allow  blacklisting  files in private home directory. By default
              these blacklists are disabled.

              Example:
              $   firejail    --allow-private-blacklist   --private=~/priv-dir
              --blacklist=~/.mozilla

      --hosts-file=file
              Use file as /etc/hosts.

              Example:
              $ firejail --hosts-file=~/myhosts firefox
             
      --writable-var-log
              Use the real /var/log directory, not  a  clone.  By  default,  a
              tmpfs  is  mounted  on top of /var/log directory, and a skeleton
              filesystem is created based on the original /var/log.

              Example:
              $ sudo firejail --writable-var-log
              
       --git-install
              Download, compile and install mainline git version  of  Firejail
              from  the  official  repository  on  GitHub.   The  software  is
              installed in /usr/local/bin, and takes precedence over the (old)
              version installed in /usr/bin. If for any reason the new version
              doesn't work, the user can uninstall  it  using  --git-uninstall
              command and revert to the old version.

              Prerequisites: git and compile support are required for this com‐
              mand to work. On Debian/Ubuntu systems this support is installed
              using "sudo apt-get install build-essential git".

              Example:

              $ firejail --git-install

       --git-uninstall
              Remove    the   Firejail   version   previously   installed   in
              /usr/local/bin using --git-install command.

              Example:

              $ firejail --git-uninstall