h4fc: 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/h4fc - from package: hdf

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

On Debian possible default full paths are:

/usr/bin/h4fc - from package: hdf4-tools

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

Error in other languages:
h4fc: bevel nie gevind nie
h4fc: comandă negăsită
h4fc: comando não encontrado
h4fc: commande introuvable
h4fc: command not found
h4fc: käsku ei ole
h4fc: không tìm thấy lệnh
h4fc: komanda nerasta
h4fc: Kommando nicht gefunden.
h4fc: kommandot finns inte
h4fc: komut yok
h4fc: nie znaleziono polecenia
h4fc: níor aimsíodh an t-ordú
h4fc: no se encontró la orden
h4fc: no s'ha trobat l'ordre
h4fc: opdracht niet gevonden
h4fc: parancs nem található
h4fc: perintah tidak ditemukan
h4fc: príkaz nenájdený
h4fc: příkaz nenalezen
h4fc: команда не найдена
h4fc: командата не е открита
h4fc: 命令找不到
h4fc: コマンドが見つかりません