napping: 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/napping - from package: nap

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

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