nwrite: 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/nwrite - from package: nwrite

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

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