ftpgrab: 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/ftpgrab - from package: ftpgrab

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

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