hdf2adf: 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/hdf2adf - from package: cgns-convert

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

Error in other languages:
hdf2adf: bevel nie gevind nie
hdf2adf: comandă negăsită
hdf2adf: comando não encontrado
hdf2adf: commande introuvable
hdf2adf: command not found
hdf2adf: käsku ei ole
hdf2adf: không tìm thấy lệnh
hdf2adf: komanda nerasta
hdf2adf: Kommando nicht gefunden.
hdf2adf: kommandot finns inte
hdf2adf: komut yok
hdf2adf: nie znaleziono polecenia
hdf2adf: níor aimsíodh an t-ordú
hdf2adf: no se encontró la orden
hdf2adf: no s'ha trobat l'ordre
hdf2adf: opdracht niet gevonden
hdf2adf: parancs nem található
hdf2adf: perintah tidak ditemukan
hdf2adf: príkaz nenájdený
hdf2adf: příkaz nenalezen
hdf2adf: команда не найдена
hdf2adf: командата не е открита
hdf2adf: 命令找不到
hdf2adf: コマンドが見つかりません