bob: 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/bob - from package: python-sponge

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

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