Fpurge: 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/Fpurge - from package: ferret-vis

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

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