hfssh: 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/hfssh - from package: hfsutils-tcltk

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

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