ncdump-hdf: 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/ncdump-hdf - from package: hdf4-tools

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

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