h4fromh5: 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/h4fromh5 - from package: h5utils

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

Error in other languages:
h4fromh5: bevel nie gevind nie
h4fromh5: comandă negăsită
h4fromh5: comando não encontrado
h4fromh5: commande introuvable
h4fromh5: command not found
h4fromh5: käsku ei ole
h4fromh5: không tìm thấy lệnh
h4fromh5: komanda nerasta
h4fromh5: Kommando nicht gefunden.
h4fromh5: kommandot finns inte
h4fromh5: komut yok
h4fromh5: nie znaleziono polecenia
h4fromh5: níor aimsíodh an t-ordú
h4fromh5: no se encontró la orden
h4fromh5: no s'ha trobat l'ordre
h4fromh5: opdracht niet gevonden
h4fromh5: parancs nem található
h4fromh5: perintah tidak ditemukan
h4fromh5: príkaz nenájdený
h4fromh5: příkaz nenalezen
h4fromh5: команда не найдена
h4fromh5: командата не е открита
h4fromh5: 命令找不到
h4fromh5: コマンドが見つかりません