cdfvhst: 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/cdfvhst - from package: cdftools

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

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