nwipe: 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 CentOS possible default full paths are:

/usr/bin/nwipe - from package: nwipe

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/nwipe - from package: nwipe

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

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