gfplus: 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/gfplus - from package: gadfly

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

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