regfiletype: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/regfiletype - from package: regina-normal

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