debfoster: 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/debfoster - from package: debfoster

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

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