sd-engf: 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
/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/sd-engf - from package: snowdrop

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