h5fromtxt: 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/h5fromtxt - from package: h5utils

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

Error in other languages:
h5fromtxt: bevel nie gevind nie
h5fromtxt: comandă negăsită
h5fromtxt: comando não encontrado
h5fromtxt: commande introuvable
h5fromtxt: command not found
h5fromtxt: käsku ei ole
h5fromtxt: không tìm thấy lệnh
h5fromtxt: komanda nerasta
h5fromtxt: Kommando nicht gefunden.
h5fromtxt: kommandot finns inte
h5fromtxt: komut yok
h5fromtxt: nie znaleziono polecenia
h5fromtxt: níor aimsíodh an t-ordú
h5fromtxt: no se encontró la orden
h5fromtxt: no s'ha trobat l'ordre
h5fromtxt: opdracht niet gevonden
h5fromtxt: parancs nem található
h5fromtxt: perintah tidak ditemukan
h5fromtxt: príkaz nenájdený
h5fromtxt: příkaz nenalezen
h5fromtxt: команда не найдена
h5fromtxt: командата не е открита
h5fromtxt: 命令找不到
h5fromtxt: コマンドが見つかりません