nap: 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/nap - from package: nap

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

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