roger: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/roger - from package: roger-router

You may install the required package with command apt-get install {package}

Error in other languages:
roger: bevel nie gevind nie
roger: comandă negăsită
roger: comando não encontrado
roger: commande introuvable
roger: command not found
roger: käsku ei ole
roger: không tìm thấy lệnh
roger: komanda nerasta
roger: Kommando nicht gefunden.
roger: kommandot finns inte
roger: komut yok
roger: nie znaleziono polecenia
roger: níor aimsíodh an t-ordú
roger: no se encontró la orden
roger: no s'ha trobat l'ordre
roger: opdracht niet gevonden
roger: parancs nem található
roger: perintah tidak ditemukan
roger: príkaz nenájdený
roger: příkaz nenalezen
roger: команда не найдена
roger: командата не е открита
roger: 命令找不到
roger: コマンドが見つかりません